Class: Sequel::Database
- Defined in:
- lib/sequel/database.rb,
lib/sequel/database/misc.rb,
lib/sequel/database/query.rb,
lib/sequel/database/dataset.rb,
lib/sequel/database/logging.rb,
lib/sequel/database/features.rb,
lib/sequel/database/connecting.rb,
lib/sequel/database/transactions.rb,
lib/sequel/database/schema_methods.rb,
lib/sequel/database/dataset_defaults.rb,
lib/sequel/extensions/run_transaction_hooks.rb
Overview
A Database object represents a virtual connection to a database. The Database class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.
Direct Known Subclasses
ADO::Database, Amalgalite::Database, IBMDB::Database, JDBC::Database, Mock::Database, MySQL::Database, Mysql2::Database, ODBC::Database, Oracle::Database, Postgres::Database, SQLite::Database, SqlAnywhere::Database, TinyTDS::Database, Trilogy::Database
Defined Under Namespace
Modules: AsyncThreadPool, RunTransactionHooks, SQLComments, SplitAlterTable
Constant Summary collapse
- OPTS =
Sequel::OPTS
- EXTENSIONS =
Hash of extension name symbols to callable objects to load the extension into the Database object (usually by extending it with a module defined in the extension).
{}
- DEFAULT_STRING_COLUMN_SIZE =
The general default size for string columns for all Sequel::Database instances.
255
- DEFAULT_DATABASE_ERROR_REGEXPS =
Empty exception regexp to class map, used by default if Sequel doesn’t have specific support for the database in use.
{}.freeze
- SCHEMA_TYPE_CLASSES =
Mapping of schema type symbols to class or arrays of classes for that symbol.
{:string=>String, :integer=>Integer, :date=>Date, :datetime=>[Time, DateTime].freeze, :time=>Sequel::SQLTime, :boolean=>[TrueClass, FalseClass].freeze, :float=>Float, :decimal=>BigDecimal, :blob=>Sequel::SQL::Blob}.freeze
- COLUMN_SCHEMA_DATETIME_TYPES =
:section: 1 - Methods that execute queries and/or return results This methods generally execute SQL code on the database server.
[:date, :datetime].freeze
- COLUMN_SCHEMA_STRING_TYPES =
[:string, :blob, :date, :datetime, :time, :enum, :set, :interval].freeze
- ADAPTERS =
Array of supported database adapters
%w'ado amalgalite ibmdb jdbc mock mysql mysql2 odbc oracle postgres sqlanywhere sqlite tinytds trilogy'.map(&:to_sym)
- TRANSACTION_ISOLATION_LEVELS =
:section: 8 - Methods related to database transactions Database transactions make multiple queries atomic, so that either all of the queries take effect or none of them do.
{:uncommitted=>'READ UNCOMMITTED'.freeze, :committed=>'READ COMMITTED'.freeze, :repeatable=>'REPEATABLE READ'.freeze, :serializable=>'SERIALIZABLE'.freeze}.freeze
- COLUMN_DEFINITION_ORDER =
The order of column modifiers to use when defining a column.
[:collate, :default, :null, :unique, :primary_key, :auto_increment, :references].freeze
- COMBINABLE_ALTER_TABLE_OPS =
The alter table operations that are combinable.
[:add_column, :drop_column, :rename_column, :set_column_type, :set_column_default, :set_column_null, :add_constraint, :drop_constraint].freeze
Instance Attribute Summary collapse
-
#cache_schema ⇒ Object
Whether the schema should be cached for this database.
-
#check_string_typecast_bytesize ⇒ Object
Whether to check the bytesize of strings before typecasting (to avoid typecasting strings that would be too long for the given type), true by default.
-
#dataset_class ⇒ Object
The class to use for creating datasets.
-
#default_string_column_size ⇒ Object
The specific default size of string columns for this Sequel::Database, usually 255 by default.
-
#log_connection_info ⇒ Object
Whether to include information about the connection in use when logging queries.
-
#log_warn_duration ⇒ Object
Numeric specifying the duration beyond which queries are logged at warn level instead of info level.
-
#loggers ⇒ Object
Array of SQL loggers to use for this database.
-
#opts ⇒ Object
readonly
The options hash for this database.
-
#pool ⇒ Object
readonly
The connection pool for this Database instance.
-
#prepared_statements ⇒ Object
readonly
The prepared statement object hash for this database, keyed by name symbol.
-
#sql_log_level ⇒ Object
Log level at which to log SQL queries.
-
#timezone ⇒ Object
The timezone to use for this database, defaulting to
Sequel.database_timezone
. -
#transaction_isolation_level ⇒ Object
The default transaction isolation level for this database, used for all future transactions.
Class Method Summary collapse
-
.adapter_class(scheme) ⇒ Object
The Database subclass for the given adapter scheme.
-
.adapter_scheme ⇒ Object
Returns the scheme symbol for the Database class.
-
.after_initialize(&block) ⇒ Object
Register a hook that will be run when a new Database is instantiated.
-
.connect(conn_string, opts = OPTS) ⇒ Object
Connects to a database.
-
.extension(*extensions) ⇒ Object
Apply an extension to all Database objects created in the future.
-
.load_adapter(scheme, opts = OPTS) ⇒ Object
Load the adapter from the file system.
-
.register_extension(ext, mod = nil, &block) ⇒ Object
Register an extension callback for Database objects.
-
.run_after_initialize(instance) ⇒ Object
Run the after_initialize hook for the given
instance
. -
.set_shared_adapter_scheme(scheme, mod) ⇒ Object
Sets the given module as the shared adapter module for the given scheme.
Instance Method Summary collapse
-
#<<(sql) ⇒ Object
Runs the supplied SQL statement string on the database server.
-
#[](*args) ⇒ Object
Returns a dataset for the database.
-
#adapter_scheme ⇒ Object
Returns the scheme symbol for this instance’s class, which reflects which adapter is being used.
-
#add_column(table, *args) ⇒ Object
Adds a column to the specified table.
-
#add_index(table, columns, options = OPTS) ⇒ Object
Adds an index to a table for the given columns:.
-
#add_servers(servers) ⇒ Object
Dynamically add new servers or modify server options at runtime.
-
#after_commit(opts = OPTS, &block) ⇒ Object
If a transaction is not currently in process, yield to the block immediately.
-
#after_rollback(opts = OPTS, &block) ⇒ Object
If a transaction is not currently in progress, ignore the block.
-
#alter_table(name, &block) ⇒ Object
Alters the given table with the specified block.
-
#alter_table_generator(&block) ⇒ Object
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
-
#call(ps_name, hash = OPTS, &block) ⇒ Object
Call the prepared statement with the given name with the given hash of arguments.
-
#cast_type_literal(type) ⇒ Object
Cast the given type to a literal type.
-
#create_join_table(hash, options = OPTS) ⇒ Object
Create a join table using a hash of foreign keys to referenced table names.
-
#create_join_table!(hash, options = OPTS) ⇒ Object
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
-
#create_join_table?(hash, options = OPTS) ⇒ Boolean
Creates the join table unless it already exists.
-
#create_or_replace_view(name, source, options = OPTS) ⇒ Object
Creates a view, replacing a view with the same name if one already exists.
-
#create_table(name, options = OPTS, &block) ⇒ Object
Creates a table with the columns given in the provided block:.
-
#create_table!(name, options = OPTS, &block) ⇒ Object
Forcibly create a table, attempting to drop it if it already exists, then creating it.
-
#create_table?(name, options = OPTS, &block) ⇒ Boolean
Creates the table unless the table already exists.
-
#create_table_generator(&block) ⇒ Object
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
-
#create_view(name, source, options = OPTS) ⇒ Object
Creates a view based on a dataset or an SQL string:.
-
#database_type ⇒ Object
The database type for this database object, the same as the adapter scheme by default.
-
#dataset ⇒ Object
Returns a blank dataset for this database.
-
#disconnect(opts = OPTS) ⇒ Object
Disconnects all available connections from the connection pool.
-
#disconnect_connection(conn) ⇒ Object
Should only be called by the connection pool code to disconnect a connection.
-
#drop_column(table, *args) ⇒ Object
Removes a column from the specified table:.
-
#drop_index(table, columns, options = OPTS) ⇒ Object
Removes an index for the given table and column(s):.
-
#drop_join_table(hash, options = OPTS) ⇒ Object
Drop the join table that would have been created with the same arguments to create_join_table:.
-
#drop_table(*names) ⇒ Object
Drops one or more tables corresponding to the given names:.
-
#drop_table?(*names) ⇒ Boolean
Drops the table if it already exists.
-
#drop_view(*names) ⇒ Object
Drops one or more views corresponding to the given names:.
-
#execute_ddl(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as
create_table
. -
#execute_dui(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when issuing a DELETE or UPDATE statement.
-
#execute_insert(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when issuing a INSERT statement.
-
#extend_datasets(mod = nil, &block) ⇒ Object
Equivalent to extending all datasets produced by the database with a module.
-
#extension(*exts) ⇒ Object
Load an extension into the receiver.
-
#fetch(sql, *args, &block) ⇒ Object
Returns a dataset instance for the given SQL string:.
-
#freeze ⇒ Object
Freeze internal data structures for the Database instance.
-
#from(*args, &block) ⇒ Object
Returns a new dataset with the
from
method invoked. -
#from_application_timestamp(v) ⇒ Object
Convert the given timestamp from the application’s timezone, to the databases’s timezone or the default database timezone if the database does not have a timezone.
-
#get(*args, &block) ⇒ Object
Returns a single value from the database, see Dataset#get.
-
#global_index_namespace? ⇒ Boolean
Whether the database uses a global namespace for the index, true by default.
-
#in_transaction?(opts = OPTS) ⇒ Boolean
Return true if already in a transaction given the options, false otherwise.
-
#initialize(opts = OPTS) ⇒ Database
constructor
Constructs a new instance of a database connection with the specified options hash.
-
#inspect ⇒ Object
Returns a string representation of the Database object, including the database type, host, database, and user, if present.
-
#literal(v) ⇒ Object
Proxy the literal call to the dataset.
-
#literal_symbol(sym) ⇒ Object
Return the literalized version of the symbol if cached, or nil if it is not cached.
-
#literal_symbol_set(sym, lit) ⇒ Object
Set the cached value of the literal symbol.
-
#log_connection_yield(sql, conn, args = nil) ⇒ Object
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
-
#log_exception(exception, message) ⇒ Object
Log a message at error level, with information about the exception.
-
#log_info(message, args = nil) ⇒ Object
Log a message at level info to all loggers.
-
#logger=(logger) ⇒ Object
Remove any existing loggers and just use the given logger:.
-
#new_connection(server) ⇒ Object
Connect to the given server/shard.
-
#prepared_statement(name) ⇒ Object
Synchronize access to the prepared statements cache.
-
#quote_identifier(v) ⇒ Object
Proxy the quote_identifier method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
-
#remove_servers(*servers) ⇒ Object
Dynamically remove existing servers from the connection pool.
-
#rename_column(table, *args) ⇒ Object
Renames a column in the specified table.
-
#rename_table(name, new_name) ⇒ Object
Renames a table:.
-
#rollback_checker(opts = OPTS) ⇒ Object
Returns a proc that you can call to check if the transaction has been rolled back.
-
#rollback_on_exit(opts = OPTS) ⇒ Object
When exiting the transaction block through methods other than an exception (e.g. normal exit, non-local return, or throw), set the current transaction to rollback instead of committing.
-
#run(sql, opts = OPTS) ⇒ Object
Runs the supplied SQL statement string on the database server.
-
#schema(table, opts = OPTS) ⇒ Object
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information.
-
#schema_type_class(type) ⇒ Object
Return ruby class or array of classes for the given type symbol.
-
#select(*args, &block) ⇒ Object
Returns a new dataset with the select method invoked.
-
#serial_primary_key_options ⇒ Object
Default serial primary key options, used by the table creation code.
-
#servers ⇒ Object
An array of servers/shards for this Database object.
-
#set_column_default(table, *args) ⇒ Object
Sets the default value for the given column in the given table:.
-
#set_column_type(table, *args) ⇒ Object
Set the data type for the given column in the given table:.
-
#set_prepared_statement(name, ps) ⇒ Object
Cache the prepared statement object at the given name.
-
#sharded? ⇒ Boolean
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
-
#single_threaded? ⇒ Boolean
Returns true if the database is using a single-threaded connection pool.
-
#supports_create_table_if_not_exists? ⇒ Boolean
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
-
#supports_deferrable_constraints? ⇒ Boolean
Whether the database supports deferrable constraints, false by default as few databases do.
-
#supports_deferrable_foreign_key_constraints? ⇒ Boolean
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
-
#supports_drop_table_if_exists? ⇒ Boolean
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
-
#supports_foreign_key_parsing? ⇒ Boolean
Whether the database supports Database#foreign_key_list for parsing foreign keys.
-
#supports_index_parsing? ⇒ Boolean
Whether the database supports Database#indexes for parsing indexes.
-
#supports_partial_indexes? ⇒ Boolean
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
-
#supports_prepared_transactions? ⇒ Boolean
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
-
#supports_savepoints? ⇒ Boolean
Whether the database and adapter support savepoints, false by default.
-
#supports_savepoints_in_prepared_transactions? ⇒ Boolean
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
-
#supports_schema_parsing? ⇒ Boolean
Whether the database supports schema parsing via Database#schema.
-
#supports_table_listing? ⇒ Boolean
Whether the database supports Database#tables for getting list of tables.
-
#supports_transaction_isolation_levels? ⇒ Boolean
Whether the database and adapter support transaction isolation levels, false by default.
-
#supports_transactional_ddl? ⇒ Boolean
Whether DDL statements work correctly in transactions, false by default.
-
#supports_view_listing? ⇒ Boolean
Whether the database supports Database#views for getting list of views.
-
#supports_views_with_check_option? ⇒ Boolean
Whether CREATE VIEW …
-
#supports_views_with_local_check_option? ⇒ Boolean
Whether CREATE VIEW …
-
#synchronize(server = nil, &block) ⇒ Object
Acquires a database connection, yielding it to the passed block.
-
#table_exists?(name) ⇒ Boolean
Returns true if a table with the given name exists.
-
#test_connection(server = nil) ⇒ Object
Attempts to acquire a database connection.
-
#to_application_timestamp(v) ⇒ Object
Convert the given timestamp to the application’s timezone, from the databases’s timezone or the default database timezone if the database does not have a timezone.
-
#transaction(opts = OPTS, &block) ⇒ Object
Starts a database transaction.
-
#typecast_value(column_type, value) ⇒ Object
Typecast the value to the given column_type.
-
#uri ⇒ Object
Returns the URI use to connect to the database.
-
#url ⇒ Object
Explicit alias of uri for easier subclassing.
-
#valid_connection?(conn) ⇒ Boolean
Check whether the given connection is currently valid, by running a query against it.
Constructor Details
#initialize(opts = OPTS) ⇒ Database
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :after_connect
-
A callable object called after each new connection is made, with the connection object (and server argument if the callable accepts 2 arguments), useful for customizations that you want to apply to all connections.
- :before_preconnect
-
Callable that runs after extensions from :preconnect_extensions are loaded, but before any connections are created.
- :cache_schema
-
Whether schema should be cached for this Database instance
- :check_string_typecast_bytesize
-
Whether to check the bytesize of strings before typecasting.
- :connect_sqls
-
An array of sql strings to execute on each new connection, after :after_connect runs.
- :connect_opts_proc
-
Callable object for modifying options hash used when connecting, designed for cases where the option values (e.g. password) are automatically rotated on a regular basis without involvement from the application using Sequel.
- :default_string_column_size
-
The default size of string columns, 255 by default.
- :extensions
-
Extensions to load into this Database instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option.
- :keep_reference
-
Whether to keep a reference to this instance in Sequel::DATABASES, true by default.
- :logger
-
A specific logger to use.
- :loggers
-
An array of loggers to use.
- :log_connection_info
-
Whether connection information should be logged when logging queries.
- :log_warn_duration
-
The number of elapsed seconds after which queries should be logged at warn level.
- :name
-
A name to use for the Database object, displayed in PoolTimeout.
- :preconnect
-
Automatically create the maximum number of connections, so that they don’t need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they’ll be created sequentially.
- :preconnect_extensions
-
Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.
- :quote_identifiers
-
Whether to quote identifiers.
- :servers
-
A hash specifying a server/shard specific options, keyed by shard symbol.
- :single_threaded
-
Whether to use a single-threaded connection pool.
- :sql_log_level
-
Method to use to log SQL to a logger, :info by default.
For sharded connection pools, :after_connect and :connect_sqls can be specified per-shard.
All options given are also passed to the connection pool. Additional options respected by the connection pool are :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.
154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 |
# File 'lib/sequel/database/misc.rb', line 154 def initialize(opts = OPTS) @opts ||= opts @opts = .merge(@opts) @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) @opts[:servers] = {} if @opts[:servers].is_a?(String) @sharded = !!@opts[:servers] @opts[:adapter_class] = self.class @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded)) @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE @check_string_typecast_bytesize = typecast_value_boolean(@opts.fetch(:check_string_typecast_bytesize, true)) @schemas = {} @prepared_statements = {} @transactions = {} @transactions.compare_by_identity @symbol_literal_cache = {} @timezone = nil @dataset_class = dataset_class_default @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) @dataset_modules = [] @loaded_extensions = [] @schema_type_classes = SCHEMA_TYPE_CLASSES.dup self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info self.log_warn_duration = @opts[:log_warn_duration] self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info]) @pool = ConnectionPool.get_pool(self, @opts) reset_default_dataset adapter_initialize keep_reference = typecast_value_boolean(@opts[:keep_reference]) != false begin Sequel.synchronize{::Sequel::DATABASES.push(self)} if keep_reference Sequel::Database.run_after_initialize(self) initialize_load_extensions(:preconnect_extensions) if before_preconnect = @opts[:before_preconnect] before_preconnect.call(self) end if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true) concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently" @pool.send(:preconnect, concurrent) end initialize_load_extensions(:extensions) test_connection if typecast_value_boolean(@opts.fetch(:test, true)) && respond_to?(:connect, true) rescue Sequel.synchronize{::Sequel::DATABASES.delete(self)} if keep_reference raise end end |
Instance Attribute Details
#cache_schema ⇒ Object
Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.
19 20 21 |
# File 'lib/sequel/database/query.rb', line 19 def cache_schema @cache_schema end |
#check_string_typecast_bytesize ⇒ Object
Whether to check the bytesize of strings before typecasting (to avoid typecasting strings that would be too long for the given type), true by default. Strings that are too long will raise a typecasting error.
110 111 112 |
# File 'lib/sequel/database/misc.rb', line 110 def check_string_typecast_bytesize @check_string_typecast_bytesize end |
#dataset_class ⇒ Object
The class to use for creating datasets. Should respond to new with the Database argument as the first argument, and an optional options hash.
13 14 15 |
# File 'lib/sequel/database/dataset_defaults.rb', line 13 def dataset_class @dataset_class end |
#default_string_column_size ⇒ Object
The specific default size of string columns for this Sequel::Database, usually 255 by default.
105 106 107 |
# File 'lib/sequel/database/misc.rb', line 105 def default_string_column_size @default_string_column_size end |
#log_connection_info ⇒ Object
Whether to include information about the connection in use when logging queries.
18 19 20 |
# File 'lib/sequel/database/logging.rb', line 18 def log_connection_info @log_connection_info end |
#log_warn_duration ⇒ Object
Numeric specifying the duration beyond which queries are logged at warn level instead of info level.
12 13 14 |
# File 'lib/sequel/database/logging.rb', line 12 def log_warn_duration @log_warn_duration end |
#loggers ⇒ Object
Array of SQL loggers to use for this database.
15 16 17 |
# File 'lib/sequel/database/logging.rb', line 15 def loggers @loggers end |
#opts ⇒ Object (readonly)
The options hash for this database
99 100 101 |
# File 'lib/sequel/database/misc.rb', line 99 def opts @opts end |
#pool ⇒ Object (readonly)
The connection pool for this Database instance. All Database instances have their own connection pools.
149 150 151 |
# File 'lib/sequel/database/connecting.rb', line 149 def pool @pool end |
#prepared_statements ⇒ Object (readonly)
The prepared statement object hash for this database, keyed by name symbol
14 15 16 |
# File 'lib/sequel/database/query.rb', line 14 def prepared_statements @prepared_statements end |
#sql_log_level ⇒ Object
Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
23 24 25 |
# File 'lib/sequel/database/logging.rb', line 23 def sql_log_level @sql_log_level end |
#timezone ⇒ Object
The timezone to use for this database, defaulting to Sequel.database_timezone
.
346 347 348 |
# File 'lib/sequel/database/misc.rb', line 346 def timezone @timezone || Sequel.database_timezone end |
#transaction_isolation_level ⇒ Object
The default transaction isolation level for this database, used for all future transactions. For MSSQL, this should be set to something if you ever plan to use the :isolation option to Database#transaction, as on MSSQL if affects all future transactions on the same connection.
22 23 24 |
# File 'lib/sequel/database/transactions.rb', line 22 def transaction_isolation_level @transaction_isolation_level end |
Class Method Details
.adapter_class(scheme) ⇒ Object
The Database subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
16 17 18 |
# File 'lib/sequel/database/connecting.rb', line 16 def self.adapter_class(scheme) scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym) end |
.adapter_scheme ⇒ Object
Returns the scheme symbol for the Database class.
21 22 23 |
# File 'lib/sequel/database/connecting.rb', line 21 def self.adapter_scheme @scheme end |
.after_initialize(&block) ⇒ Object
Register a hook that will be run when a new Database is instantiated. It is called with the new database handle.
39 40 41 42 43 44 45 46 47 48 |
# File 'lib/sequel/database/misc.rb', line 39 def self.after_initialize(&block) raise Error, "must provide block to after_initialize" unless block Sequel.synchronize do previous = @initialize_hook @initialize_hook = proc do |db| previous.call(db) block.call(db) end end end |
.connect(conn_string, opts = OPTS) ⇒ Object
Connects to a database. See Sequel.connect.
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 |
# File 'lib/sequel/database/connecting.rb', line 26 def self.connect(conn_string, opts = OPTS) case conn_string when String if conn_string.start_with?('jdbc:') c = adapter_class(:jdbc) opts = opts.merge(:orig_opts=>opts.dup) opts = {:uri=>conn_string}.merge!(opts) else uri = URI.parse(conn_string) scheme = uri.scheme c = adapter_class(scheme) opts = c.send(:options_from_uri, uri).merge!(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) end when Hash opts = conn_string.merge(opts) opts = opts.merge(:orig_opts=>opts.dup) c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) else raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" end opts = opts.inject({}) do |m, (k,v)| k = :user if k.to_s == 'username' m[k.to_sym] = v m end begin db = c.new(opts) if defined?(yield) return yield(db) end ensure if defined?(yield) db.disconnect if db Sequel.synchronize{::Sequel::DATABASES.delete(db)} end end db end |
.extension(*extensions) ⇒ Object
Apply an extension to all Database objects created in the future.
51 52 53 |
# File 'lib/sequel/database/misc.rb', line 51 def self.extension(*extensions) after_initialize{|db| db.extension(*extensions)} end |
.load_adapter(scheme, opts = OPTS) ⇒ Object
Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn’t registered correctly after being loaded. Options:
- :map
-
The Hash in which to look for an already loaded adapter (defaults to ADAPTER_MAP).
- :subdir
-
The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.
73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 |
# File 'lib/sequel/database/connecting.rb', line 73 def self.load_adapter(scheme, opts=OPTS) map = opts[:map] || ADAPTER_MAP if subdir = opts[:subdir] file = "#{subdir}/#{scheme}" else file = scheme end unless obj = Sequel.synchronize{map[scheme]} # attempt to load the adapter file begin require "sequel/adapters/#{file}" rescue LoadError => e # If subadapter file doesn't exist, just return, # using the main adapter class without database customizations. return if subdir raise Sequel.convert_exception_class(e, AdapterNotFound) end # make sure we actually loaded the adapter unless obj = Sequel.synchronize{map[scheme]} raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP" end end obj end |
.register_extension(ext, mod = nil, &block) ⇒ Object
Register an extension callback for Database objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
60 61 62 63 64 65 66 67 68 69 70 |
# File 'lib/sequel/database/misc.rb', line 60 def self.register_extension(ext, mod=nil, &block) if mod raise(Error, "cannot provide both mod and block to Database.register_extension") if block if mod.is_a?(Module) block = proc{|db| db.extend(mod)} else block = mod end end Sequel.synchronize{EXTENSIONS[ext] = block} end |
.run_after_initialize(instance) ⇒ Object
Run the after_initialize hook for the given instance
.
73 74 75 |
# File 'lib/sequel/database/misc.rb', line 73 def self.run_after_initialize(instance) @initialize_hook.call(instance) end |
.set_shared_adapter_scheme(scheme, mod) ⇒ Object
Sets the given module as the shared adapter module for the given scheme. Used to register shared adapters for use by the mock adapter. Example:
# in file sequel/adapters/shared/mydb.rb
module Sequel::MyDB
Sequel::Database.set_shared_adapter_scheme :mydb, self
def self.mock_adapter_setup(db)
# ...
end
module DatabaseMethods
# ...
end
module DatasetMethods
# ...
end
end
would allow the mock adapter to return a Database instance that supports the MyDB syntax via:
Sequel.connect('mock://mydb')
143 144 145 |
# File 'lib/sequel/database/connecting.rb', line 143 def self.set_shared_adapter_scheme(scheme, mod) Sequel.synchronize{SHARED_ADAPTER_MAP[scheme] = mod} end |
Instance Method Details
#<<(sql) ⇒ Object
Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:
DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
25 26 27 28 |
# File 'lib/sequel/database/query.rb', line 25 def <<(sql) run(sql) self end |
#[](*args) ⇒ Object
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all
DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
21 22 23 |
# File 'lib/sequel/database/dataset.rb', line 21 def [](*args) args.first.is_a?(String) ? fetch(*args) : from(*args) end |
#adapter_scheme ⇒ Object
Returns the scheme symbol for this instance’s class, which reflects which adapter is being used. In some cases, this can be the same as the database_type
(for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme
# => :jdbc
158 159 160 |
# File 'lib/sequel/database/connecting.rb', line 158 def adapter_scheme self.class.adapter_scheme end |
#add_column(table, *args) ⇒ Object
25 26 27 |
# File 'lib/sequel/database/schema_methods.rb', line 25 def add_column(table, *args) alter_table(table) {add_column(*args)} end |
#add_index(table, columns, options = OPTS) ⇒ Object
Adds an index to a table for the given columns:
DB.add_index :posts, :title
DB.add_index :posts, [:author, :title], unique: true
Options:
- :ignore_errors
-
Ignore any DatabaseErrors that are raised
- :name
-
Name to use for index instead of default
See alter_table
.
40 41 42 43 44 45 46 47 48 |
# File 'lib/sequel/database/schema_methods.rb', line 40 def add_index(table, columns, =OPTS) e = [:ignore_errors] begin alter_table(table){add_index(columns, )} rescue DatabaseError raise unless e end nil end |
#add_servers(servers) ⇒ Object
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it’s value is overridden with the value provided.
DB.add_servers(f: {host: "hash_host_f"})
170 171 172 173 174 175 176 177 178 |
# File 'lib/sequel/database/connecting.rb', line 170 def add_servers(servers) unless sharded? raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool" end h = @opts[:servers] Sequel.synchronize{h.merge!(servers)} @pool.add_servers(servers.keys) end |
#after_commit(opts = OPTS, &block) ⇒ Object
If a transaction is not currently in process, yield to the block immediately. Otherwise, add the block to the list of blocks to call after the currently in progress transaction commits (and only if it commits). Options:
- :savepoint
-
If currently inside a savepoint, only run this hook on transaction commit if all enclosing savepoints have been released.
- :server
-
The server/shard to use.
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 |
# File 'lib/sequel/database/transactions.rb', line 31 def after_commit(opts=OPTS, &block) raise Error, "must provide block to after_commit" unless block synchronize(opts[:server]) do |conn| if h = _trans(conn) raise Error, "cannot call after_commit in a prepared transaction" if h[:prepare] if opts[:savepoint] && in_savepoint?(conn) add_savepoint_hook(conn, :after_commit, block) else add_transaction_hook(conn, :after_commit, block) end else yield end end end |
#after_rollback(opts = OPTS, &block) ⇒ Object
If a transaction is not currently in progress, ignore the block. Otherwise, add the block to the list of the blocks to call after the currently in progress transaction rolls back (and only if it rolls back). Options:
- :savepoint
-
If currently inside a savepoint, run this hook immediately when any enclosing savepoint is rolled back, which may be before the transaction commits or rollsback.
- :server
-
The server/shard to use.
55 56 57 58 59 60 61 62 63 64 65 66 67 |
# File 'lib/sequel/database/transactions.rb', line 55 def after_rollback(opts=OPTS, &block) raise Error, "must provide block to after_rollback" unless block synchronize(opts[:server]) do |conn| if h = _trans(conn) raise Error, "cannot call after_rollback in a prepared transaction" if h[:prepare] if opts[:savepoint] && in_savepoint?(conn) add_savepoint_hook(conn, :after_rollback, block) else add_transaction_hook(conn, :after_rollback, block) end end end end |
#alter_table(name, &block) ⇒ Object
Alters the given table with the specified block. Example:
DB.alter_table :items do
add_column :category, String, default: 'ruby'
drop_column :category
rename_column :cntr, :counter
set_column_type :value, Float
set_column_default :value, 4.2
add_index [:group, :category]
drop_index [:group, :category]
end
Note that add_column
accepts all the options available for column definitions using create_table
, and add_index
accepts all the options available for index definition.
See Schema::AlterTableGenerator
and the Migrations guide.
67 68 69 70 71 72 |
# File 'lib/sequel/database/schema_methods.rb', line 67 def alter_table(name, &block) generator = alter_table_generator(&block) remove_cached_schema(name) apply_alter_table_generator(name, generator) nil end |
#alter_table_generator(&block) ⇒ Object
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
76 77 78 |
# File 'lib/sequel/database/schema_methods.rb', line 76 def alter_table_generator(&block) alter_table_generator_class.new(self, &block) end |
#call(ps_name, hash = OPTS, &block) ⇒ Object
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].where(id: 1).prepare(:first, :sa)
DB.call(:sa) # SELECT * FROM items WHERE id = 1
35 36 37 |
# File 'lib/sequel/database/query.rb', line 35 def call(ps_name, hash=OPTS, &block) prepared_statement(ps_name).call(hash, &block) end |
#cast_type_literal(type) ⇒ Object
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision
DB.cast_type_literal(:foo) # foo
239 240 241 |
# File 'lib/sequel/database/misc.rb', line 239 def cast_type_literal(type) type_literal(:type=>type) end |
#create_join_table(hash, options = OPTS) ⇒ Object
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(cat_id: :cats, dog_id: :dogs)
# CREATE TABLE cats_dogs (
# cat_id integer NOT NULL REFERENCES cats,
# dog_id integer NOT NULL REFERENCES dogs,
# PRIMARY KEY (cat_id, dog_id)
# )
# CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:
create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs
create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)
You can provide a second argument which is a table options hash:
create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)
Some table options are handled specially:
- :index_options
-
The options to pass to the index
- :name
-
The name of the table to create
- :no_index
-
Set to true not to create the second index.
- :no_primary_key
-
Set to true to not create the primary key.
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 |
# File 'lib/sequel/database/schema_methods.rb', line 119 def create_join_table(hash, =OPTS) keys = hash.keys.sort create_table(join_table_name(hash, ), ) do keys.each do |key| v = hash[key] unless v.is_a?(Hash) v = {:table=>v} end v[:null] = false unless v.has_key?(:null) foreign_key(key, v) end primary_key(keys) unless [:no_primary_key] index(keys.reverse, [:index_options] || OPTS) unless [:no_index] end nil end |
#create_join_table!(hash, options = OPTS) ⇒ Object
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
137 138 139 140 |
# File 'lib/sequel/database/schema_methods.rb', line 137 def create_join_table!(hash, =OPTS) drop_table?(join_table_name(hash, )) create_join_table(hash, ) end |
#create_join_table?(hash, options = OPTS) ⇒ Boolean
Creates the join table unless it already exists.
143 144 145 146 147 148 149 |
# File 'lib/sequel/database/schema_methods.rb', line 143 def create_join_table?(hash, =OPTS) if supports_create_table_if_not_exists? && [:no_index] create_join_table(hash, .merge(:if_not_exists=>true)) elsif !table_exists?(join_table_name(hash, )) create_join_table(hash, ) end end |
#create_or_replace_view(name, source, options = OPTS) ⇒ Object
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100")
DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
256 257 258 259 260 261 262 263 264 265 |
# File 'lib/sequel/database/schema_methods.rb', line 256 def create_or_replace_view(name, source, = OPTS) if supports_create_or_replace_view? && ![:materialized] = .merge(:replace=>true) else swallow_database_error{drop_view(name, )} end create_view(name, source, ) nil end |
#create_table(name, options = OPTS, &block) ⇒ Object
Creates a table with the columns given in the provided block:
DB.create_table :posts do
primary_key :id
column :title, String
String :content
index :title
end
General options:
- :as
-
Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method.
- :ignore_index_errors
-
Ignore any errors when creating indexes.
- :temp
-
Create the table as a temporary table.
MySQL specific options:
- :charset
-
The character set to use for the table.
- :collate
-
The collation to use for the table.
- :engine
-
The table engine to use for the table.
PostgreSQL specific options:
- :on_commit
-
Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.
- :foreign
-
Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.
- :inherits
-
Inherit from a different table. An array can be specified to inherit from multiple tables.
- :unlogged
-
Create the table as an unlogged table.
- :options
-
The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.
- :tablespace
-
The tablespace to use for the table.
SQLite specific options:
- :strict
-
Create a STRICT table, which checks that the values for the columns are the correct type (similar to all other SQL databases). Note that when using this option, all column types used should be one of the following:
int
,integer
,real
,text
,blob
, andany
. Theany
type is treated like a SQLite column in a non-strict table, allowing any type of data to be stored. This option is supported on SQLite 3.37.0+. - :using
-
Create a VIRTUAL table with the given USING clause. The value should be a string, as it is used directly in the SQL query.
- :without_rowid
-
Create a WITHOUT ROWID table. Every row in SQLite has a special ‘rowid’ column, that uniquely identifies that row within the table. If this option is used, the ‘rowid’ column is omitted, which can sometimes provide some space and speed advantages. Note that you must then provide an explicit primary key when you create the table. This option is supported on SQLite 3.8.2+.
See Schema::CreateTableGenerator
and the “Schema Modification” guide.
204 205 206 207 208 209 210 211 212 213 214 215 |
# File 'lib/sequel/database/schema_methods.rb', line 204 def create_table(name, =OPTS, &block) remove_cached_schema(name) if sql = [:as] raise(Error, "can't provide both :as option and block to create_table") if block create_table_as(name, sql, ) else generator = [:generator] || create_table_generator(&block) create_table_from_generator(name, generator, ) create_table_indexes_from_generator(name, generator, ) end nil end |
#create_table!(name, options = OPTS, &block) ⇒ Object
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a}
# SELECT NULL FROM a LIMIT 1 -- check existence
# DROP TABLE a -- drop table if already exists
# CREATE TABLE a (a integer)
223 224 225 226 |
# File 'lib/sequel/database/schema_methods.rb', line 223 def create_table!(name, =OPTS, &block) drop_table?(name) create_table(name, , &block) end |
#create_table?(name, options = OPTS, &block) ⇒ Boolean
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a}
# SELECT NULL FROM a LIMIT 1 -- check existence
# CREATE TABLE a (a integer) -- if it doesn't already exist
233 234 235 236 237 238 239 240 241 |
# File 'lib/sequel/database/schema_methods.rb', line 233 def create_table?(name, =OPTS, &block) = .dup generator = [:generator] ||= create_table_generator(&block) if generator.indexes.empty? && supports_create_table_if_not_exists? create_table(name, .merge!(:if_not_exists=>true)) elsif !table_exists?(name) create_table(name, ) end end |
#create_table_generator(&block) ⇒ Object
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
245 246 247 |
# File 'lib/sequel/database/schema_methods.rb', line 245 def create_table_generator(&block) create_table_generator_class.new(self, &block) end |
#create_view(name, source, options = OPTS) ⇒ Object
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
# CREATE VIEW cheap_items AS
# SELECT * FROM items WHERE price < 100
DB.create_view(:ruby_items, DB[:items].where(category: 'ruby'))
# CREATE VIEW ruby_items AS
# SELECT * FROM items WHERE (category = 'ruby')
DB.create_view(:checked_items, DB[:items].where(:foo), check: true)
# CREATE VIEW checked_items AS
# SELECT * FROM items WHERE foo
# WITH CHECK OPTION
DB.create_view(:bar_items, DB[:items].select(:foo), columns: [:bar])
# CREATE VIEW bar_items (bar) AS
# SELECT foo FROM items
Options:
- :columns
-
The column names to use for the view. If not given, automatically determined based on the input dataset.
- :check
-
Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.
PostgreSQL/SQLite specific option:
- :temp
-
Create a temporary view, automatically dropped on disconnect.
PostgreSQL specific options:
- :materialized
-
Creates a materialized view, similar to a regular view, but backed by a physical table.
- :recursive
-
Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn’t in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the all: true and from_self: false options.
- :security_invoker
-
Set the security_invoker property on the view, making the access to the view use the current user’s permissions, instead of the view owner’s permissions.
- :tablespace
-
The tablespace to use for materialized views.
310 311 312 313 314 |
# File 'lib/sequel/database/schema_methods.rb', line 310 def create_view(name, source, = OPTS) execute_ddl(create_view_sql(name, source, )) remove_cached_schema(name) nil end |
#database_type ⇒ Object
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database objects that are using the same adapter are connecting to different database types.
Sequel.connect('jdbc:postgres://...').database_type
# => :postgres
189 190 191 |
# File 'lib/sequel/database/connecting.rb', line 189 def database_type adapter_scheme end |
#dataset ⇒ Object
Returns a blank dataset for this database.
DB.dataset # SELECT *
DB.dataset.from(:items) # SELECT * FROM items
29 30 31 |
# File 'lib/sequel/database/dataset.rb', line 29 def dataset @dataset_class.new(self) end |
#disconnect(opts = OPTS) ⇒ Object
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :server
-
Should be a symbol specifing the server to disconnect from,
or an array of symbols to specify multiple servers.
Example:
DB.disconnect # All servers
DB.disconnect(server: :server1) # Single server
DB.disconnect(server: [:server1, :server2]) # Multiple servers
203 204 205 |
# File 'lib/sequel/database/connecting.rb', line 203 def disconnect(opts = OPTS) pool.disconnect(opts) end |
#disconnect_connection(conn) ⇒ Object
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
210 211 212 |
# File 'lib/sequel/database/connecting.rb', line 210 def disconnect_connection(conn) conn.close end |
#drop_column(table, *args) ⇒ Object
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
321 322 323 |
# File 'lib/sequel/database/schema_methods.rb', line 321 def drop_column(table, *args) alter_table(table) {drop_column(*args)} end |
#drop_index(table, columns, options = OPTS) ⇒ Object
Removes an index for the given table and column(s):
DB.drop_index :posts, :title
DB.drop_index :posts, [:author, :title]
See alter_table
.
331 332 333 |
# File 'lib/sequel/database/schema_methods.rb', line 331 def drop_index(table, columns, =OPTS) alter_table(table){drop_index(columns, )} end |
#drop_join_table(hash, options = OPTS) ⇒ Object
Drop the join table that would have been created with the same arguments to create_join_table:
drop_join_table(cat_id: :cats, dog_id: :dogs)
# DROP TABLE cats_dogs
340 341 342 |
# File 'lib/sequel/database/schema_methods.rb', line 340 def drop_join_table(hash, =OPTS) drop_table(join_table_name(hash, ), ) end |
#drop_table(*names) ⇒ Object
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts
DB.drop_table(:posts, :comments)
DB.drop_table(:posts, :comments, cascade: true)
349 350 351 352 353 354 355 356 |
# File 'lib/sequel/database/schema_methods.rb', line 349 def drop_table(*names) = names.last.is_a?(Hash) ? names.pop : OPTS names.each do |n| execute_ddl(drop_table_sql(n, )) remove_cached_schema(n) end nil end |
#drop_table?(*names) ⇒ Boolean
Drops the table if it already exists. If it doesn’t exist, does nothing.
DB.drop_table?(:a)
# SELECT NULL FROM a LIMIT 1 -- check existence
# DROP TABLE a -- if it already exists
364 365 366 367 368 369 370 371 372 373 374 375 376 377 |
# File 'lib/sequel/database/schema_methods.rb', line 364 def drop_table?(*names) = names.last.is_a?(Hash) ? names.pop : OPTS if supports_drop_table_if_exists? = .merge(:if_exists=>true) names.each do |name| drop_table(name, ) end else names.each do |name| drop_table(name, ) if table_exists?(name) end end nil end |
#drop_view(*names) ⇒ Object
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items)
DB.drop_view(:cheap_items, :pricey_items)
DB.drop_view(:cheap_items, :pricey_items, cascade: true)
DB.drop_view(:cheap_items, :pricey_items, if_exists: true)
Options:
- :cascade
-
Also drop objects depending on this view.
- :if_exists
-
Do not raise an error if the view does not exist.
PostgreSQL specific options:
- :materialized
-
Drop a materialized view.
392 393 394 395 396 397 398 399 |
# File 'lib/sequel/database/schema_methods.rb', line 392 def drop_view(*names) = names.last.is_a?(Hash) ? names.pop : OPTS names.each do |n| execute_ddl(drop_view_sql(n, )) remove_cached_schema(n) end nil end |
#execute_ddl(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table
. By default, calls execute_dui
. This method should not be called directly by user code.
42 43 44 |
# File 'lib/sequel/database/query.rb', line 42 def execute_ddl(sql, opts=OPTS, &block) execute_dui(sql, opts, &block) end |
#execute_dui(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.
49 50 51 |
# File 'lib/sequel/database/query.rb', line 49 def execute_dui(sql, opts=OPTS, &block) execute(sql, opts, &block) end |
#execute_insert(sql, opts = OPTS, &block) ⇒ Object
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
56 57 58 |
# File 'lib/sequel/database/query.rb', line 56 def execute_insert(sql, opts=OPTS, &block) execute_dui(sql, opts, &block) end |
#extend_datasets(mod = nil, &block) ⇒ Object
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class as the new dataset_class, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database object uses.
If a block is given, a Dataset::DatasetModule instance is created, allowing for the easy creation of named dataset methods that will do caching.
Examples:
# Introspect columns for all of DB's datasets
DB.extend_datasets(Sequel::ColumnsIntrospection)
# Trace all SELECT queries by printing the SQL and the full backtrace
DB.extend_datasets do
def fetch_rows(sql)
puts sql
puts caller
super
end
end
# Add some named dataset methods
DB.extend_datasets do
order :by_id, :id
select :with_id_and_name, :id, :name
where :active, :active
end
DB[:table].active.with_id_and_name.by_id
# SELECT id, name FROM table WHERE active ORDER BY id
62 63 64 65 66 67 68 69 70 71 72 73 |
# File 'lib/sequel/database/dataset_defaults.rb', line 62 def extend_datasets(mod=nil, &block) raise(Error, "must provide either mod or block, not both") if mod && block mod = Dataset::DatasetModule.new(&block) if block if @dataset_modules.empty? @dataset_modules = [mod] @dataset_class = Class.new(@dataset_class) else @dataset_modules << mod end @dataset_class.send(:include, mod) reset_default_dataset end |
#extension(*exts) ⇒ Object
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database objects, an Error will be raised. Returns self.
248 249 250 251 252 253 254 255 256 257 258 259 260 |
# File 'lib/sequel/database/misc.rb', line 248 def extension(*exts) Sequel.extension(*exts) exts.each do |ext| if pr = Sequel.synchronize{EXTENSIONS[ext]} if Sequel.synchronize{@loaded_extensions.include?(ext) ? false : (@loaded_extensions << ext)} pr.call(self) end else raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})") end end self end |
#fetch(sql, *args, &block) ⇒ Object
Returns a dataset instance for the given SQL string:
ds = DB.fetch('SELECT * FROM items')
You can then call methods on the dataset to retrieve results:
ds.all
# SELECT * FROM items
# => [{:column=>value, ...}, ...]
If a block is given, it is passed to #each on the resulting dataset to iterate over the records returned by the query:
DB.fetch('SELECT * FROM items'){|r| p r}
# {:column=>value, ...}
# ...
fetch
can also perform parameterized queries for protection against SQL injection:
ds = DB.fetch('SELECT * FROM items WHERE name = ?', "my name")
ds.all
# SELECT * FROM items WHERE name = 'my name'
See caveats listed in Dataset#with_sql regarding datasets using custom SQL and the methods that can be called on them.
59 60 61 62 63 |
# File 'lib/sequel/database/dataset.rb', line 59 def fetch(sql, *args, &block) ds = @default_dataset.with_sql(sql, *args) ds.each(&block) if block ds end |
#freeze ⇒ Object
Freeze internal data structures for the Database instance.
213 214 215 216 217 218 219 220 221 222 223 224 225 |
# File 'lib/sequel/database/misc.rb', line 213 def freeze valid_connection_sql @opts.freeze @loggers.freeze @pool.freeze @dataset_class.freeze @dataset_modules.freeze @schema_type_classes.freeze @loaded_extensions.freeze super end |
#from(*args, &block) ⇒ Object
Returns a new dataset with the from
method invoked. If a block is given, it acts as a virtual row block
DB.from(:items) # SELECT * FROM items
DB.from{schema[:table]} # SELECT * FROM schema.table
70 71 72 73 74 75 76 77 78 |
# File 'lib/sequel/database/dataset.rb', line 70 def from(*args, &block) if block @default_dataset.from(*args, &block) elsif args.length == 1 && (table = args[0]).is_a?(Symbol) @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)} else @default_dataset.from(*args) end end |
#from_application_timestamp(v) ⇒ Object
Convert the given timestamp from the application’s timezone, to the databases’s timezone or the default database timezone if the database does not have a timezone.
265 266 267 |
# File 'lib/sequel/database/misc.rb', line 265 def (v) Sequel.(v, timezone) end |
#get(*args, &block) ⇒ Object
Returns a single value from the database, see Dataset#get.
DB.get(1) # SELECT 1
# => 1
DB.get{server_version.function} # SELECT server_version()
65 66 67 |
# File 'lib/sequel/database/query.rb', line 65 def get(*args, &block) @default_dataset.get(*args, &block) end |
#global_index_namespace? ⇒ Boolean
Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.
13 14 15 |
# File 'lib/sequel/database/features.rb', line 13 def global_index_namespace? true end |
#in_transaction?(opts = OPTS) ⇒ Boolean
Return true if already in a transaction given the options, false otherwise. Respects the :server option for selecting a shard.
113 114 115 |
# File 'lib/sequel/database/transactions.rb', line 113 def in_transaction?(opts=OPTS) synchronize(opts[:server]){|conn| !!_trans(conn)} end |
#inspect ⇒ Object
Returns a string representation of the Database object, including the database type, host, database, and user, if present.
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 |
# File 'lib/sequel/database/misc.rb', line 271 def inspect s = String.new s << "#<#{self.class}" s << " database_type=#{database_type}" if database_type && database_type != adapter_scheme keys = [:host, :database, :user] opts = self.opts if !keys.any?{|k| opts[k]} && opts[:uri] opts = self.class.send(:options_from_uri, URI.parse(opts[:uri])) end keys.each do |key| val = opts[key] if val && val != '' s << " #{key}=#{val}" end end s << ">" end |
#literal(v) ⇒ Object
Proxy the literal call to the dataset.
DB.literal(1) # 1
DB.literal(:a) # "a" # or `a`, [a], or a, depending on identifier quoting
DB.literal("a") # 'a'
297 298 299 |
# File 'lib/sequel/database/misc.rb', line 297 def literal(v) schema_utility_dataset.literal(v) end |
#literal_symbol(sym) ⇒ Object
Return the literalized version of the symbol if cached, or nil if it is not cached.
303 304 305 |
# File 'lib/sequel/database/misc.rb', line 303 def literal_symbol(sym) Sequel.synchronize{@symbol_literal_cache[sym]} end |
#literal_symbol_set(sym, lit) ⇒ Object
Set the cached value of the literal symbol.
308 309 310 |
# File 'lib/sequel/database/misc.rb', line 308 def literal_symbol_set(sym, lit) Sequel.synchronize{@symbol_literal_cache[sym] = lit} end |
#log_connection_yield(sql, conn, args = nil) ⇒ Object
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
37 38 39 40 41 42 43 44 45 46 47 48 49 50 |
# File 'lib/sequel/database/logging.rb', line 37 def log_connection_yield(sql, conn, args=nil) return yield if skip_logging? sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}" timer = Sequel.start_timer begin yield rescue => e log_exception(e, sql) raise ensure log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e end end |
#log_exception(exception, message) ⇒ Object
Log a message at error level, with information about the exception.
26 27 28 |
# File 'lib/sequel/database/logging.rb', line 26 def log_exception(exception, ) log_each(:error, "#{exception.class}: #{exception..strip if exception.}: #{}") end |
#log_info(message, args = nil) ⇒ Object
Log a message at level info to all loggers.
31 32 33 |
# File 'lib/sequel/database/logging.rb', line 31 def log_info(, args=nil) log_each(:info, args ? "#{}; #{args.inspect}" : ) end |
#logger=(logger) ⇒ Object
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
55 56 57 |
# File 'lib/sequel/database/logging.rb', line 55 def logger=(logger) @loggers = Array(logger) end |
#new_connection(server) ⇒ Object
Connect to the given server/shard. Handles database-generic post-connection setup not handled by #connect, using the :after_connect and :connect_sqls options.
244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 |
# File 'lib/sequel/database/connecting.rb', line 244 def new_connection(server) conn = connect(server) opts = server_opts(server) if ac = opts[:after_connect] if ac.arity == 2 ac.call(conn, server) else ac.call(conn) end end if cs = opts[:connect_sqls] cs.each do |sql| log_connection_execute(conn, sql) end end conn end |
#prepared_statement(name) ⇒ Object
Synchronize access to the prepared statements cache.
313 314 315 |
# File 'lib/sequel/database/misc.rb', line 313 def prepared_statement(name) Sequel.synchronize{prepared_statements[name]} end |
#quote_identifier(v) ⇒ Object
Proxy the quote_identifier method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
320 321 322 |
# File 'lib/sequel/database/misc.rb', line 320 def quote_identifier(v) schema_utility_dataset.quote_identifier(v) end |
#remove_servers(*servers) ⇒ Object
Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
223 224 225 226 227 228 229 230 231 |
# File 'lib/sequel/database/connecting.rb', line 223 def remove_servers(*servers) unless sharded? raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool" end h = @opts[:servers] servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} @pool.remove_servers(servers) end |
#rename_column(table, *args) ⇒ Object
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table
.
418 419 420 |
# File 'lib/sequel/database/schema_methods.rb', line 418 def rename_column(table, *args) alter_table(table) {rename_column(*args)} end |
#rename_table(name, new_name) ⇒ Object
Renames a table:
DB.tables #=> [:items]
DB.rename_table :items, :old_items
DB.tables #=> [:old_items]
406 407 408 409 410 |
# File 'lib/sequel/database/schema_methods.rb', line 406 def rename_table(name, new_name) execute_ddl(rename_table_sql(name, new_name)) remove_cached_schema(name) nil end |
#rollback_checker(opts = OPTS) ⇒ Object
Returns a proc that you can call to check if the transaction has been rolled back. The proc will return nil if the transaction is still in progress, true if the transaction was rolled back, and false if it was committed. Raises an Error if called outside a transaction. Respects the :server option for selecting a shard.
123 124 125 126 127 128 |
# File 'lib/sequel/database/transactions.rb', line 123 def rollback_checker(opts=OPTS) synchronize(opts[:server]) do |conn| raise Error, "not in a transaction" unless t = _trans(conn) t[:rollback_checker] ||= proc{Sequel.synchronize{t[:rolled_back]}} end end |
#rollback_on_exit(opts = OPTS) ⇒ Object
When exiting the transaction block through methods other than an exception (e.g. normal exit, non-local return, or throw), set the current transaction to rollback instead of committing. This is designed for use in cases where you want to preform a non-local return but also want to rollback instead of committing. Options:
- :cancel
-
Cancel the current rollback_on_exit setting, so exiting will commit instead of rolling back.
- :savepoint
-
Rollback only the current savepoint if inside a savepoint. Can also be an positive integer value to rollback that number of enclosing savepoints, up to and including the transaction itself. If the database does not support savepoints, this option is ignored and the entire transaction is affected.
- :server
-
The server/shard the transaction is being executed on.
83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 |
# File 'lib/sequel/database/transactions.rb', line 83 def rollback_on_exit(opts=OPTS) synchronize(opts[:server]) do |conn| raise Error, "Cannot call Sequel:: Database#rollback_on_exit unless inside a transaction" unless h = _trans(conn) rollback = !opts[:cancel] if supports_savepoints? savepoints = h[:savepoints] if level = opts[:savepoint] level = 1 if level == true raise Error, "invalid :savepoint option to Database#rollback_on_exit: #{level.inspect}" unless level.is_a?(Integer) raise Error, "cannot pass nonpositive integer (#{level.inspect}) as :savepoint option to Database#rollback_on_exit" if level < 1 level.times do |i| break unless savepoint = savepoints[-1 - i] savepoint[:rollback_on_exit] = rollback end else savepoints[0][:rollback_on_exit] = rollback end else h[:rollback_on_exit] = rollback end end nil end |
#run(sql, opts = OPTS) ⇒ Object
Runs the supplied SQL statement string on the database server. Returns nil. Options:
- :server
-
The server to run the SQL on.
DB.run("SET some_server_variable = 42")
74 75 76 77 78 |
# File 'lib/sequel/database/query.rb', line 74 def run(sql, opts=OPTS) sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) execute_ddl(sql, opts) nil end |
#schema(table, opts = OPTS) ⇒ Object
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
- :reload
-
Ignore any cached results, and get fresh information from the database.
- :schema
-
An explicit schema to use. It may also be implicitly provided via the table name.
If schema parsing is supported by the database, the column information hash should contain at least the following entries:
- :allow_null
-
Whether NULL is an allowed value for the column.
- :db_type
-
The database type for the column, as a database specific string.
- :default
-
The database default for the column, as a database specific string, or nil if there is no default value.
- :primary_key
-
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.
- :ruby_default
-
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.
- :type
-
A symbol specifying the type, such as :integer or :string.
Example:
DB.schema(:artists)
# [[:id,
# {:type=>:integer,
# :primary_key=>true,
# :default=>"nextval('artist_id_seq'::regclass)",
# :ruby_default=>nil,
# :db_type=>"integer",
# :allow_null=>false}],
# [:name,
# {:type=>:string,
# :primary_key=>false,
# :default=>nil,
# :ruby_default=>nil,
# :db_type=>"text",
# :allow_null=>false}]]
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 |
# File 'lib/sequel/database/query.rb', line 121 def schema(table, opts=OPTS) raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? opts = opts.dup tab = if table.is_a?(Dataset) o = table.opts from = o[:from] raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) table.first_source_table else table end qualifiers = split_qualifiers(tab) table_name = qualifiers.pop sch = qualifiers.pop information_schema_schema = case qualifiers.length when 1 Sequel.identifier(*qualifiers) when 2 Sequel.qualify(*qualifiers) end if table.is_a?(Dataset) quoted_name = table.literal(tab) opts[:dataset] = table else quoted_name = schema_utility_dataset.literal(table) end opts[:schema] = sch if sch && !opts.include?(:schema) opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] if v = Sequel.synchronize{@schemas[quoted_name]} return v end cols = schema_parse_table(table_name, opts) raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty? primary_keys = 0 auto_increment_set = false cols.each do |_,c| auto_increment_set = true if c.has_key?(:auto_increment) primary_keys += 1 if c[:primary_key] end cols.each do |_,c| c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default) if c[:primary_key] && !auto_increment_set # If adapter didn't set it, assume that integer primary keys are auto incrementing c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io) end if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type])) c[:max_length] = max_length end if !c[:max_value] && !c[:min_value] min_max = case c[:type] when :integer column_schema_integer_min_max_values(c) when :decimal column_schema_decimal_min_max_values(c) end c[:min_value], c[:max_value] = min_max if min_max end end schema_post_process(cols) Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema cols end |
#schema_type_class(type) ⇒ Object
Return ruby class or array of classes for the given type symbol.
325 326 327 |
# File 'lib/sequel/database/misc.rb', line 325 def schema_type_class(type) @schema_type_classes[type] end |
#select(*args, &block) ⇒ Object
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1
DB.select{server_version.function} # SELECT server_version()
DB.select(:id).from(:items) # SELECT id FROM items
85 86 87 |
# File 'lib/sequel/database/dataset.rb', line 85 def select(*args, &block) @default_dataset.select(*args, &block) end |
#serial_primary_key_options ⇒ Object
Default serial primary key options, used by the table creation code.
330 331 332 |
# File 'lib/sequel/database/misc.rb', line 330 def {:primary_key => true, :type => Integer, :auto_increment => true} end |
#servers ⇒ Object
An array of servers/shards for this Database object.
DB.servers # Unsharded: => [:default]
DB.servers # Sharded: => [:default, :server1, :server2]
237 238 239 |
# File 'lib/sequel/database/connecting.rb', line 237 def servers pool.servers end |
#set_column_default(table, *args) ⇒ Object
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table
.
427 428 429 |
# File 'lib/sequel/database/schema_methods.rb', line 427 def set_column_default(table, *args) alter_table(table) {set_column_default(*args)} end |
#set_column_type(table, *args) ⇒ Object
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table
.
436 437 438 |
# File 'lib/sequel/database/schema_methods.rb', line 436 def set_column_type(table, *args) alter_table(table) {set_column_type(*args)} end |
#set_prepared_statement(name, ps) ⇒ Object
Cache the prepared statement object at the given name.
335 336 337 |
# File 'lib/sequel/database/misc.rb', line 335 def set_prepared_statement(name, ps) Sequel.synchronize{prepared_statements[name] = ps} end |
#sharded? ⇒ Boolean
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
341 342 343 |
# File 'lib/sequel/database/misc.rb', line 341 def sharded? @sharded end |
#single_threaded? ⇒ Boolean
Returns true if the database is using a single-threaded connection pool.
266 267 268 |
# File 'lib/sequel/database/connecting.rb', line 266 def single_threaded? @single_threaded end |
#supports_create_table_if_not_exists? ⇒ Boolean
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
19 20 21 |
# File 'lib/sequel/database/features.rb', line 19 def supports_create_table_if_not_exists? false end |
#supports_deferrable_constraints? ⇒ Boolean
Whether the database supports deferrable constraints, false by default as few databases do.
25 26 27 |
# File 'lib/sequel/database/features.rb', line 25 def supports_deferrable_constraints? false end |
#supports_deferrable_foreign_key_constraints? ⇒ Boolean
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
31 32 33 |
# File 'lib/sequel/database/features.rb', line 31 def supports_deferrable_foreign_key_constraints? supports_deferrable_constraints? end |
#supports_drop_table_if_exists? ⇒ Boolean
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
37 38 39 |
# File 'lib/sequel/database/features.rb', line 37 def supports_drop_table_if_exists? supports_create_table_if_not_exists? end |
#supports_foreign_key_parsing? ⇒ Boolean
Whether the database supports Database#foreign_key_list for parsing foreign keys.
43 44 45 |
# File 'lib/sequel/database/features.rb', line 43 def supports_foreign_key_parsing? respond_to?(:foreign_key_list) end |
#supports_index_parsing? ⇒ Boolean
Whether the database supports Database#indexes for parsing indexes.
48 49 50 |
# File 'lib/sequel/database/features.rb', line 48 def supports_index_parsing? respond_to?(:indexes) end |
#supports_partial_indexes? ⇒ Boolean
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
54 55 56 |
# File 'lib/sequel/database/features.rb', line 54 def supports_partial_indexes? false end |
#supports_prepared_transactions? ⇒ Boolean
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
60 61 62 |
# File 'lib/sequel/database/features.rb', line 60 def supports_prepared_transactions? false end |
#supports_savepoints? ⇒ Boolean
Whether the database and adapter support savepoints, false by default.
65 66 67 |
# File 'lib/sequel/database/features.rb', line 65 def supports_savepoints? false end |
#supports_savepoints_in_prepared_transactions? ⇒ Boolean
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
71 72 73 |
# File 'lib/sequel/database/features.rb', line 71 def supports_savepoints_in_prepared_transactions? supports_prepared_transactions? && supports_savepoints? end |
#supports_schema_parsing? ⇒ Boolean
Whether the database supports schema parsing via Database#schema.
76 77 78 |
# File 'lib/sequel/database/features.rb', line 76 def supports_schema_parsing? respond_to?(:schema_parse_table, true) end |
#supports_table_listing? ⇒ Boolean
Whether the database supports Database#tables for getting list of tables.
81 82 83 |
# File 'lib/sequel/database/features.rb', line 81 def supports_table_listing? respond_to?(:tables) end |
#supports_transaction_isolation_levels? ⇒ Boolean
Whether the database and adapter support transaction isolation levels, false by default.
91 92 93 |
# File 'lib/sequel/database/features.rb', line 91 def supports_transaction_isolation_levels? false end |
#supports_transactional_ddl? ⇒ Boolean
Whether DDL statements work correctly in transactions, false by default.
96 97 98 |
# File 'lib/sequel/database/features.rb', line 96 def supports_transactional_ddl? false end |
#supports_view_listing? ⇒ Boolean
Whether the database supports Database#views for getting list of views.
86 87 88 |
# File 'lib/sequel/database/features.rb', line 86 def supports_view_listing? respond_to?(:views) end |
#supports_views_with_check_option? ⇒ Boolean
Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.
101 102 103 |
# File 'lib/sequel/database/features.rb', line 101 def supports_views_with_check_option? !!view_with_check_option_support end |
#supports_views_with_local_check_option? ⇒ Boolean
Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.
106 107 108 |
# File 'lib/sequel/database/features.rb', line 106 def supports_views_with_local_check_option? view_with_check_option_support == :local end |
#synchronize(server = nil, &block) ⇒ Object
Acquires a database connection, yielding it to the passed block. This is useful if you want to make sure the same connection is used for all database queries in the block. It is also useful if you want to gain direct access to the underlying connection object if you need to do something Sequel does not natively support.
If a server option is given, acquires a connection for that specific server, instead of the :default server.
DB.synchronize do |conn|
# ...
end
282 283 284 |
# File 'lib/sequel/database/connecting.rb', line 282 def synchronize(server=nil, &block) @pool.hold(server || :default, &block) end |
#table_exists?(name) ⇒ Boolean
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false
# SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don’t have permission to SELECT from the table.
202 203 204 205 206 207 208 209 210 |
# File 'lib/sequel/database/query.rb', line 202 def table_exists?(name) sch, table_name = schema_and_table(name) name = SQL::QualifiedIdentifier.new(sch, table_name) if sch ds = from(name) transaction(:savepoint=>:only){_table_exists?(ds)} true rescue DatabaseError false end |
#test_connection(server = nil) ⇒ Object
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
290 291 292 293 |
# File 'lib/sequel/database/connecting.rb', line 290 def test_connection(server=nil) synchronize(server){|conn|} true end |
#to_application_timestamp(v) ⇒ Object
Convert the given timestamp to the application’s timezone, from the databases’s timezone or the default database timezone if the database does not have a timezone.
353 354 355 |
# File 'lib/sequel/database/misc.rb', line 353 def (v) Sequel.(v, timezone) end |
#transaction(opts = OPTS, &block) ⇒ Object
Starts a database transaction. When a database transaction is used, either all statements are successful or none of the statements are successful. Note that MySQL MyISAM tables do not support transactions.
The following general options are respected:
- :auto_savepoint
-
Automatically use a savepoint for Database#transaction calls inside this transaction block.
- :isolation
-
The transaction isolation level to use for this transaction, should be :uncommitted, :committed, :repeatable, or :serializable, used if given and the database/adapter supports customizable transaction isolation levels.
- :num_retries
-
The number of times to retry if the :retry_on option is used. The default is 5 times. Can be set to nil to retry indefinitely, but that is not recommended.
- :before_retry
-
Proc to execute before retrying if the :retry_on option is used. Called with two arguments: the number of retry attempts (counting the current one) and the error the last attempt failed with.
- :prepare
-
A string to use as the transaction identifier for a prepared transaction (two-phase commit), if the database/adapter supports prepared transactions.
- :retry_on
-
An exception class or array of exception classes for which to automatically retry the transaction. Can only be set if not inside an existing transaction. Note that this should not be used unless the entire transaction block is idempotent, as otherwise it can cause non-idempotent behavior to execute multiple times.
- :rollback
-
Can be set to :reraise to reraise any Sequel::Rollback exceptions raised, or :always to always rollback even if no exceptions occur (useful for testing).
- :server
-
The server to use for the transaction. Set to :default, :read_only, or whatever symbol you used in the connect string when naming your servers.
- :savepoint
-
Whether to create a new savepoint for this transaction, only respected if the database/adapter supports savepoints. By default Sequel will reuse an existing transaction, so if you want to use a savepoint you must use this option. If the surrounding transaction uses :auto_savepoint, you can set this to false to not use a savepoint. If the value given for this option is :only, it will only create a savepoint if it is inside a transaction.
- :skip_transaction
-
If set, do not actually open a transaction or savepoint, just checkout a connection and yield it.
PostgreSQL specific options:
- :deferrable
-
(9.1+) If present, set to DEFERRABLE if true or NOT DEFERRABLE if false.
- :read_only
-
If present, set to READ ONLY if true or READ WRITE if false.
- :synchronous
-
if non-nil, set synchronous_commit appropriately. Valid values true, :on, false, :off, :local (9.1+), and :remote_write (9.2+).
179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 |
# File 'lib/sequel/database/transactions.rb', line 179 def transaction(opts=OPTS, &block) opts = Hash[opts] if retry_on = opts[:retry_on] tot_retries = opts.fetch(:num_retries, 5) num_retries = 0 begin opts[:retry_on] = nil opts[:retrying] = true transaction(opts, &block) rescue *retry_on => e num_retries += 1 if tot_retries.nil? || num_retries <= tot_retries opts[:before_retry].call(num_retries, e) if opts[:before_retry] retry end raise end else synchronize(opts[:server]) do |conn| if opts[:skip_transaction] return yield(conn) end if opts[:savepoint] == :only if supports_savepoints? if _trans(conn) opts[:savepoint] = true else return yield(conn) end else opts[:savepoint] = false end end if opts[:savepoint] && !supports_savepoints? raise Sequel::InvalidOperation, "savepoints not supported on #{database_type}" end if already_in_transaction?(conn, opts) if opts[:rollback] == :always && !opts.has_key?(:savepoint) if supports_savepoints? opts[:savepoint] = true else raise Sequel::Error, "cannot set :rollback=>:always transaction option if already inside a transaction" end end if opts[:savepoint] != false && (stack = _trans(conn)[:savepoints]) && stack.last[:auto_savepoint] opts[:savepoint] = true end unless opts[:savepoint] if opts[:retrying] raise Sequel::Error, "cannot set :retry_on options if you are already inside a transaction" end return yield(conn) end end _transaction(conn, opts, &block) end end end |
#typecast_value(column_type, value) ⇒ Object
Typecast the value to the given column_type. Calls typecast_value_#column_type if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
362 363 364 365 366 367 368 369 370 371 |
# File 'lib/sequel/database/misc.rb', line 362 def typecast_value(column_type, value) return nil if value.nil? meth = "typecast_value_#{column_type}" begin # Allow calling private methods as per-type typecasting methods are private respond_to?(meth, true) ? send(meth, value) : value rescue ArgumentError, TypeError => e raise Sequel.convert_exception_class(e, InvalidValue) end end |
#uri ⇒ Object
Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.
375 376 377 |
# File 'lib/sequel/database/misc.rb', line 375 def uri opts[:uri] end |
#url ⇒ Object
Explicit alias of uri for easier subclassing.
380 381 382 |
# File 'lib/sequel/database/misc.rb', line 380 def url uri end |
#valid_connection?(conn) ⇒ Boolean
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
299 300 301 302 303 304 305 306 307 308 |
# File 'lib/sequel/database/connecting.rb', line 299 def valid_connection?(conn) sql = valid_connection_sql begin log_connection_execute(conn, sql) rescue Sequel::DatabaseError, *database_error_classes false else true end end |