Class: Sequel::Database
- Extended by:
- Metaprogramming
- Includes:
- Metaprogramming
- 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/extensions/query.rb,
lib/sequel/database/connecting.rb,
lib/sequel/database/schema_methods.rb,
lib/sequel/extensions/schema_dumper.rb,
lib/sequel/database/dataset_defaults.rb,
lib/sequel/extensions/schema_caching.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, Sequel::DB2::Database, Sequel::DBI::Database, Sequel::DataObjects::Database, Firebird::Database, IBMDB::Database, Informix::Database, JDBC::Database, Mock::Database, MySQL::Database, Mysql2::Database, ODBC::Database, OpenBase::Database, Oracle::Database, Postgres::Database, SQLite::Database, Swift::Database, TinyTDS::Database
Constant Summary collapse
- SQL_BEGIN =
:section: 1 - Methods that execute queries and/or return results This methods generally execute SQL code on the database server.
'BEGIN'.freeze
- SQL_COMMIT =
'COMMIT'.freeze
- SQL_RELEASE_SAVEPOINT =
'RELEASE SAVEPOINT autopoint_%d'.freeze
- SQL_ROLLBACK =
'ROLLBACK'.freeze
- SQL_ROLLBACK_TO_SAVEPOINT =
'ROLLBACK TO SAVEPOINT autopoint_%d'.freeze
- SQL_SAVEPOINT =
'SAVEPOINT autopoint_%d'.freeze
- TRANSACTION_BEGIN =
'Transaction.begin'.freeze
- TRANSACTION_COMMIT =
'Transaction.commit'.freeze
- TRANSACTION_ROLLBACK =
'Transaction.rollback'.freeze
- TRANSACTION_ISOLATION_LEVELS =
{:uncommitted=>'READ UNCOMMITTED'.freeze, :committed=>'READ COMMITTED'.freeze, :repeatable=>'REPEATABLE READ'.freeze, :serializable=>'SERIALIZABLE'.freeze}
- POSTGRES_DEFAULT_RE =
/\A(?:B?('.*')::[^']+|\((-?\d+(?:\.\d+)?)\))\z/
- MSSQL_DEFAULT_RE =
/\A(?:\(N?('.*')\)|\(\((-?\d+(?:\.\d+)?)\)\))\z/
- MYSQL_TIMESTAMP_RE =
/\ACURRENT_(?:DATE|TIMESTAMP)?\z/
- STRING_DEFAULT_RE =
/\A'(.*)'\z/
- ADAPTERS =
Array of supported database adapters
%w'ado amalgalite db2 dbi do firebird ibmdb informix jdbc mock mysql mysql2 odbc openbase oracle postgres sqlite swift tinytds'.collect{|x| x.to_sym}
- AUTOINCREMENT =
:section: 2 - Methods that modify the database schema These methods execute code on the database that modifies the database’s schema.
'AUTOINCREMENT'.freeze
- COMMA_SEPARATOR =
', '.freeze
- NOT_NULL =
' NOT NULL'.freeze
- NULL =
' NULL'.freeze
- PRIMARY_KEY =
' PRIMARY KEY'.freeze
- TEMPORARY =
'TEMPORARY '.freeze
- UNDERSCORE =
'_'.freeze
- UNIQUE =
' UNIQUE'.freeze
- UNSIGNED =
' UNSIGNED'.freeze
- COLUMN_DEFINITION_ORDER =
The order of column modifiers to use when defining a column.
[:collate, :default, :null, :unique, :primary_key, :auto_increment, :references]
- DEFAULT_JOIN_TABLE_COLUMN_OPTIONS =
The default options for join table columns.
{:null=>false}
- DatasetClass =
The default class to use for datasets
Sequel::Dataset
- @@single_threaded =
Whether to use the single threaded connection pool by default
false
- @@identifier_input_method =
The identifier input method to use by default
nil
- @@identifier_output_method =
The identifier output method to use by default
nil
- @@quote_identifiers =
Whether to quote identifiers (columns and tables) by default
nil
Instance Attribute Summary collapse
-
#cache_schema ⇒ Object
Whether the schema should be cached for this database.
-
#dataset_class ⇒ Object
The class to use for creating datasets.
-
#default_schema ⇒ Object
The default schema to use, generally should be nil.
-
#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.
-
.connect(conn_string, opts = {}) ⇒ Object
Connects to a database.
-
.identifier_input_method ⇒ Object
The method to call on identifiers going into the database.
-
.identifier_input_method=(v) ⇒ Object
Set the method to call on identifiers going into the database See Sequel.identifier_input_method=.
-
.identifier_output_method ⇒ Object
The method to call on identifiers coming from the database.
-
.identifier_output_method=(v) ⇒ Object
Set the method to call on identifiers coming from the database See Sequel.identifier_output_method=.
-
.quote_identifiers=(value) ⇒ Object
Sets the default quote_identifiers mode for new databases.
-
.single_threaded=(value) ⇒ Object
Sets the default single_threaded mode for new databases.
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 = {}) ⇒ 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 = {}, &block) ⇒ Object
If a transaction is not currently in process, yield to the block immediately.
-
#after_rollback(opts = {}, &block) ⇒ Object
If a transaction is not currently in progress, ignore the block.
-
#alter_table(name, generator = nil, &block) ⇒ Object
Alters the given table with the specified block.
-
#call(ps_name, hash = {}) ⇒ 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.
-
#connect(server) ⇒ Object
Connects to the database.
-
#create_join_table(hash, options = {}) ⇒ Object
Create a join table using a hash of foreign keys to referenced table names.
-
#create_or_replace_view(name, source) ⇒ Object
Creates a view, replacing it if it already exists:.
-
#create_table(name, options = {}, &block) ⇒ Object
Creates a table with the columns given in the provided block:.
-
#create_table!(name, options = {}, &block) ⇒ Object
Forcibly create a table, attempting to drop it if it already exists, then creating it.
-
#create_table?(name, options = {}, &block) ⇒ Boolean
Creates the table unless the table already exists.
-
#create_view(name, source) ⇒ 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(opts = nil) ⇒ Object
Returns a blank dataset for this database.
-
#disconnect(opts = {}) ⇒ Object
Disconnects all available connections from the connection pool.
-
#drop_column(table, *args) ⇒ Object
Removes a column from the specified table:.
-
#drop_index(table, columns, options = {}) ⇒ Object
Removes an index for the given table and column/s:.
-
#drop_join_table(hash, options = {}) ⇒ 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:.
-
#dump_foreign_key_migration(options = {}) ⇒ Object
Dump foreign key constraints for all tables as a migration.
-
#dump_indexes_migration(options = {}) ⇒ Object
Dump indexes for all tables as a migration.
-
#dump_schema_cache(file) ⇒ Object
Dump the cached schema to the filename given in Marshal format.
-
#dump_schema_cache?(file) ⇒ Boolean
Dump the cached schema to the filename given unless the file already exists.
-
#dump_schema_migration(options = {}) ⇒ Object
Return a string that contains a Sequel::Migration subclass that when run would recreate the database structure.
-
#dump_table_schema(table, options = {}) ⇒ Object
Return a string with a create table block that will recreate the given table’s schema.
-
#each_server(&block) ⇒ Object
Yield a new Database instance for every server in the connection pool.
-
#execute(sql, opts = {}) ⇒ Object
Executes the given SQL on the database.
-
#execute_ddl(sql, opts = {}, &block) ⇒ Object
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as
create_table
. -
#execute_dui(sql, opts = {}, &block) ⇒ Object
Method that should be used when issuing a DELETE, UPDATE, or INSERT statement.
-
#execute_insert(sql, 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.
-
#fetch(sql, *args, &block) ⇒ Object
Fetches records for an arbitrary SQL statement.
-
#foreign_key_list(table, opts = {}) ⇒ Object
Returns an array of hashes containing foreign key information from the table.
-
#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, e.g.:.
-
#identifier_input_method ⇒ Object
The method to call on identifiers going into the database.
-
#identifier_input_method=(v) ⇒ Object
Set the method to call on identifiers going into the database:.
-
#identifier_output_method ⇒ Object
The method to call on identifiers coming from the database.
-
#identifier_output_method=(v) ⇒ Object
Set the method to call on identifiers coming from the database:.
-
#in_transaction?(opts = {}) ⇒ Boolean
Return true if already in a transaction given the options, false otherwise.
-
#indexes(table, opts = {}) ⇒ Object
Return a hash containing index information for the table.
-
#initialize(opts = {}, &block) ⇒ 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 class name and connection URI and options used when connecting (if any).
-
#literal(v) ⇒ Object
Proxy the literal call to the dataset.
-
#load_schema_cache(file) ⇒ Object
Replace the schema cache with the data from the given file, which should be in Marshal format.
-
#load_schema_cache?(file) ⇒ Boolean
Replace the schema cache with the data from the given file if the file exists.
-
#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.
-
#log_yield(sql, 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.
-
#logger=(logger) ⇒ Object
Remove any existing loggers and just use the given logger:.
-
#prepared_statement(name) ⇒ Object
Synchronize access to the prepared statements cache.
-
#query(&block) ⇒ Object
Return a dataset modified by the query block.
-
#quote_identifiers=(v) ⇒ Object
Set whether to quote identifiers (columns and tables) for this database:.
-
#quote_identifiers? ⇒ Boolean
Returns true if the database quotes identifiers.
-
#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:.
-
#run(sql, opts = {}) ⇒ Object
Runs the supplied SQL statement string on the database server.
-
#schema(table, 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.
-
#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.
-
#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_drop_table_if_exists? ⇒ Boolean
Whether the database supports DROP TABLE IF EXISTS syntax, default is the same as #supports_create_table_if_not_exists?.
-
#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), default is false.
-
#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.
-
#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.
-
#tables(opts = {}) ⇒ Object
Return all tables in the database as an array of symbols.
-
#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 = {}, &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.
-
#views(opts = {}) ⇒ Object
Return all views in the database as an array of symbols.
Methods included from Metaprogramming
Constructor Details
#initialize(opts = {}, &block) ⇒ Database
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :default_schema
-
The default schema to use, should generally be nil
- :disconnection_proc
-
A proc used to disconnect the connection
- :identifier_input_method
-
A string method symbol to call on identifiers going into the database
- :identifier_output_method
-
A string method symbol to call on identifiers coming from the database
- :logger
-
A specific logger to use
- :loggers
-
An array of loggers to use
- :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.
All options given are also passed to the connection pool. If a block is given, it is used as the connection_proc for the ConnectionPool.
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# File 'lib/sequel/database/misc.rb', line 42 def initialize(opts = {}, &block) @opts ||= opts @opts = .merge(@opts) @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) self.log_warn_duration = @opts[:log_warn_duration] @opts[:disconnection_proc] ||= proc{|conn| disconnect_connection(conn)} block ||= proc{|server| connect(server)} @opts[:servers] = {} if @opts[:servers].is_a?(String) @opts[:adapter_class] = self.class @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, @@single_threaded)) @schemas = {} @default_schema = @opts.fetch(:default_schema, default_schema_default) @prepared_statements = {} @transactions = {} @identifier_input_method = nil @identifier_output_method = nil @quote_identifiers = nil @timezone = nil @dataset_class = dataset_class_default @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) @dataset_modules = [] self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info @pool = ConnectionPool.get_pool(@opts, &block) Sequel.synchronize{::Sequel::DATABASES.push(self)} 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.
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# File 'lib/sequel/database/query.rb', line 42 def cache_schema @cache_schema 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.
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# File 'lib/sequel/database/dataset_defaults.rb', line 51 def dataset_class @dataset_class end |
#default_schema ⇒ Object
The default schema to use, generally should be nil.
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# File 'lib/sequel/database/dataset_defaults.rb', line 54 def default_schema @default_schema end |
#log_warn_duration ⇒ Object
Numeric specifying the duration beyond which queries are logged at warn level instead of info level.
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# File 'lib/sequel/database/logging.rb', line 10 def log_warn_duration @log_warn_duration end |
#loggers ⇒ Object
Array of SQL loggers to use for this database.
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# File 'lib/sequel/database/logging.rb', line 13 def loggers @loggers end |
#opts ⇒ Object (readonly)
The options hash for this database
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# File 'lib/sequel/database/misc.rb', line 20 def opts @opts end |
#pool ⇒ Object (readonly)
The connection pool for this Database instance. All Database instances have their own connection pools.
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# File 'lib/sequel/database/connecting.rb', line 116 def pool @pool end |
#prepared_statements ⇒ Object (readonly)
The prepared statement object hash for this database, keyed by name symbol
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# File 'lib/sequel/database/query.rb', line 30 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.
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# File 'lib/sequel/database/logging.rb', line 18 def sql_log_level @sql_log_level end |
#timezone ⇒ Object
The timezone to use for this database, defaulting to Sequel.database_timezone
.
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# File 'lib/sequel/database/misc.rb', line 200 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.
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# File 'lib/sequel/database/query.rb', line 37 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.
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# File 'lib/sequel/database/connecting.rb', line 17 def self.adapter_class(scheme) return scheme if scheme.is_a?(Class) scheme = scheme.to_s.gsub('-', '_').to_sym unless klass = ADAPTER_MAP[scheme] # attempt to load the adapter file begin Sequel.tsk_require "sequel/adapters/#{scheme}" rescue LoadError => e raise Sequel.convert_exception_class(e, AdapterNotFound) end # make sure we actually loaded the adapter unless klass = ADAPTER_MAP[scheme] raise AdapterNotFound, "Could not load #{scheme} adapter: adapter class not registered in ADAPTER_MAP" end end klass end |
.adapter_scheme ⇒ Object
Returns the scheme symbol for the Database class.
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# File 'lib/sequel/database/connecting.rb', line 39 def self.adapter_scheme @scheme end |
.connect(conn_string, opts = {}) ⇒ Object
Connects to a database. See Sequel.connect.
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# File 'lib/sequel/database/connecting.rb', line 44 def self.connect(conn_string, opts = {}) case conn_string when String if match = /\A(jdbc|do):/o.match(conn_string) c = adapter_class(match[1].to_sym) opts = opts.merge(:orig_opts=>opts.dup) opts = {:uri=>conn_string}.merge(opts) else uri = URI.parse(conn_string) scheme = uri.scheme scheme = :dbi if scheme =~ /\Adbi-/ c = adapter_class(scheme) = c.send(:uri_to_options, uri) uri.query.split('&').collect{|s| s.split('=')}.each{|k,v| [k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? .to_a.each{|k,v| [k] = URI.unescape(v) if v.is_a?(String)} opts = opts.merge(:orig_opts=>opts.dup) opts[:uri] = conn_string opts = .merge(opts) opts[: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 # process opts a bit 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) db.test_connection if opts[:test] && db.send(:typecast_value_boolean, opts[:test]) result = yield(db) if block_given? ensure if block_given? db.disconnect if db Sequel.synchronize{::Sequel::DATABASES.delete(db)} end end block_given? ? result : db end |
.identifier_input_method ⇒ Object
The method to call on identifiers going into the database
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# File 'lib/sequel/database/dataset_defaults.rb', line 21 def self.identifier_input_method @@identifier_input_method end |
.identifier_input_method=(v) ⇒ Object
Set the method to call on identifiers going into the database See Sequel.identifier_input_method=.
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# File 'lib/sequel/database/dataset_defaults.rb', line 27 def self.identifier_input_method=(v) @@identifier_input_method = v || "" end |
.identifier_output_method ⇒ Object
The method to call on identifiers coming from the database
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# File 'lib/sequel/database/dataset_defaults.rb', line 32 def self.identifier_output_method @@identifier_output_method end |
.identifier_output_method=(v) ⇒ Object
Set the method to call on identifiers coming from the database See Sequel.identifier_output_method=.
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# File 'lib/sequel/database/dataset_defaults.rb', line 38 def self.identifier_output_method=(v) @@identifier_output_method = v || "" end |
.quote_identifiers=(value) ⇒ Object
Sets the default quote_identifiers mode for new databases. See Sequel.quote_identifiers=.
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# File 'lib/sequel/database/dataset_defaults.rb', line 44 def self.quote_identifiers=(value) @@quote_identifiers = value end |
.single_threaded=(value) ⇒ Object
Sets the default single_threaded mode for new databases. See Sequel.single_threaded=.
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# File 'lib/sequel/database/connecting.rb', line 92 def self.single_threaded=(value) @@single_threaded = value 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"
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# File 'lib/sequel/database/query.rb', line 48 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"
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# File 'lib/sequel/database/dataset.rb', line 19 def [](*args) (String === args.first) ? 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
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# File 'lib/sequel/database/connecting.rb', line 124 def adapter_scheme self.class.adapter_scheme end |
#add_column(table, *args) ⇒ Object
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, :text, :unique => true, :null => false
DB.add_column :items, :category, :text, :default => 'ruby'
See alter_table
.
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# File 'lib/sequel/database/schema_methods.rb', line 31 def add_column(table, *args) alter_table(table) {add_column(*args)} end |
#add_index(table, columns, options = {}) ⇒ 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
See alter_table
.
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# File 'lib/sequel/database/schema_methods.rb', line 44 def add_index(table, columns, ={}) e = [:ignore_errors] begin alter_table(table){add_index(columns, )} rescue DatabaseError raise unless e end end |
#add_servers(servers) ⇒ Object
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Intended for use with master/slave or shard configurations where it is useful to add new server hosts at runtime.
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"})
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# File 'lib/sequel/database/connecting.rb', line 137 def add_servers(servers) if h = @opts[:servers] Sequel.synchronize{h.merge!(servers)} @pool.add_servers(servers.keys) end end |
#after_commit(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:
- :server
-
The server/shard to use.
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# File 'lib/sequel/database/misc.rb', line 75 def after_commit(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] (h[:after_commit] ||= []) << block else yield end end end |
#after_rollback(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:
- :server
-
The server/shard to use.
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# File 'lib/sequel/database/misc.rb', line 92 def after_rollback(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] (h[:after_rollback] ||= []) << block end end end |
#alter_table(name, generator = nil, &block) ⇒ Object
Alters the given table with the specified block. Example:
DB.alter_table :items do
add_column :category, :text, :default => 'ruby'
drop_column :category
rename_column :cntr, :counter
set_column_type :value, :float
set_column_default :value, :float
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 and Schema Modification” guide.
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# File 'lib/sequel/database/schema_methods.rb', line 70 def alter_table(name, generator=nil, &block) generator ||= Schema::AlterTableGenerator.new(self, &block) remove_cached_schema(name) apply_alter_table(name, generator.operations) nil end |
#call(ps_name, hash = {}) ⇒ Object
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].filter(:id=>1).prepare(:first, :sa)
DB.call(:sa) # SELECT * FROM items WHERE id = 1
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# File 'lib/sequel/database/query.rb', line 58 def call(ps_name, hash={}) prepared_statement(ps_name).call(hash) 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
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# File 'lib/sequel/database/misc.rb', line 106 def cast_type_literal(type) type_literal(:type=>type) end |
#connect(server) ⇒ Object
Connects to the database. This method should be overridden by descendants.
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# File 'lib/sequel/database/connecting.rb', line 145 def connect(server) raise NotImplemented, "#connect should be overridden by adapters" end |
#create_join_table(hash, options = {}) ⇒ 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.
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.
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# File 'lib/sequel/database/schema_methods.rb', line 109 def create_join_table(hash, ={}) keys = hash.keys.sort_by{|k| k.to_s} create_table(join_table_name(hash, ), ) do keys.each do |key| v = hash[key] unless v.is_a?(Hash) v = {:table=>v} end v = DEFAULT_JOIN_TABLE_COLUMN_OPTIONS.merge(v) foreign_key(key, v) end primary_key(keys) unless [:no_primary_key] index(keys.reverse, [:index_options] || {}) unless [:no_index] end end |
#create_or_replace_view(name, source) ⇒ Object
Creates a view, replacing it if it already exists:
DB.create_or_replace_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
DB.create_or_replace_view(:ruby_items, DB[:items].filter(:category => 'ruby'))
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# File 'lib/sequel/database/schema_methods.rb', line 184 def create_or_replace_view(name, source) source = source.sql if source.is_a?(Dataset) execute_ddl("CREATE OR REPLACE VIEW #{quote_schema_table(name)} AS #{source}") remove_cached_schema(name) nil end |
#create_table(name, options = {}, &block) ⇒ Object
Creates a table with the columns given in the provided block:
DB.create_table :posts do
primary_key :id
column :title, :text
String :content
index :title
end
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.
See Schema::Generator
and the “Schema Modification” guide.
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# File 'lib/sequel/database/schema_methods.rb', line 142 def create_table(name, ={}, &block) remove_cached_schema(name) = {:generator=>} if .is_a?(Schema::Generator) 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] || Schema::Generator.new(self, &block) create_table_from_generator(name, generator, ) create_table_indexes_from_generator(name, generator, ) nil end end |
#create_table!(name, options = {}, &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)
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# File 'lib/sequel/database/schema_methods.rb', line 162 def create_table!(name, ={}, &block) drop_table?(name) create_table(name, , &block) end |
#create_table?(name, options = {}, &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
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# File 'lib/sequel/database/schema_methods.rb', line 172 def create_table?(name, ={}, &block) if supports_create_table_if_not_exists? create_table(name, .merge(:if_not_exists=>true), &block) elsif !table_exists?(name) create_table(name, , &block) end end |
#create_view(name, source) ⇒ Object
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100")
DB.create_view(:ruby_items, DB[:items].filter(:category => 'ruby'))
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# File 'lib/sequel/database/schema_methods.rb', line 195 def create_view(name, source) source = source.sql if source.is_a?(Dataset) execute_ddl("CREATE VIEW #{quote_schema_table(name)} AS #{source}") 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 (think JDBC or DataObjects).
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
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# File 'lib/sequel/database/connecting.rb', line 158 def database_type adapter_scheme end |
#dataset(opts = nil) ⇒ Object
Returns a blank dataset for this database.
DB.dataset # SELECT *
DB.dataset.from(:items) # SELECT * FROM items
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# File 'lib/sequel/database/dataset.rb', line 27 def dataset(opts=nil) @dataset_class.new(self, opts) end |
#disconnect(opts = {}) ⇒ Object
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :servers
-
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(:servers=>:server1) # Single server
DB.disconnect(:servers=>[:server1, :server2]) # Multiple servers
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# File 'lib/sequel/database/connecting.rb', line 172 def disconnect(opts = {}) pool.disconnect(opts) end |
#drop_column(table, *args) ⇒ Object
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
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# File 'lib/sequel/database/schema_methods.rb', line 205 def drop_column(table, *args) alter_table(table) {drop_column(*args)} end |
#drop_index(table, columns, options = {}) ⇒ 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
.
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# File 'lib/sequel/database/schema_methods.rb', line 215 def drop_index(table, columns, ={}) alter_table(table){drop_index(columns, )} end |
#drop_join_table(hash, options = {}) ⇒ 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
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# File 'lib/sequel/database/schema_methods.rb', line 224 def drop_join_table(hash, ={}) 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)
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# File 'lib/sequel/database/schema_methods.rb', line 233 def drop_table(*names) = names.last.is_a?(Hash) ? names.pop : {} 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
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# File 'lib/sequel/database/schema_methods.rb', line 248 def drop_table?(*names) = names.last.is_a?(Hash) ? names.pop : {} 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 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)
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# File 'lib/sequel/database/schema_methods.rb', line 267 def drop_view(*names) = names.last.is_a?(Hash) ? names.pop : {} names.each do |n| execute_ddl(drop_view_sql(n, )) remove_cached_schema(n) end nil end |
#dump_foreign_key_migration(options = {}) ⇒ Object
Dump foreign key constraints for all tables as a migration. This complements the :foreign_keys=>false option to dump_schema_migration. This only dumps the constraints (not the columns) using alter_table/add_foreign_key with an array of columns.
Note that the migration this produces does not have a down block, so you cannot reverse it.
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# File 'lib/sequel/extensions/schema_dumper.rb', line 16 def dump_foreign_key_migration(={}) ts = tables() <<END_MIG Sequel.migration do up do #{ts.sort_by{|t| t.to_s}.map{|t| dump_table_foreign_keys(t)}.reject{|x| x == ''}.join("\n\n").gsub(/^/o, ' ')} end end END_MIG end |
#dump_indexes_migration(options = {}) ⇒ Object
Dump indexes for all tables as a migration. This complements the :indexes=>false option to dump_schema_migration. Options:
-
:same_db - Create a dump for the same database type, so don’t ignore errors if the index statements fail.
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# File 'lib/sequel/extensions/schema_dumper.rb', line 31 def dump_indexes_migration(={}) ts = tables() <<END_MIG Sequel.migration do up do #{ts.sort_by{|t| t.to_s}.map{|t| dump_table_indexes(t, :add_index, )}.reject{|x| x == ''}.join("\n\n").gsub(/^/o, ' ')} end down do #{ts.sort_by{|t| t.to_s}.reverse.map{|t| dump_table_indexes(t, :drop_index, )}.reject{|x| x == ''}.join("\n\n").gsub(/^/o, ' ')} end end END_MIG end |
#dump_schema_cache(file) ⇒ Object
Dump the cached schema to the filename given in Marshal format.
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# File 'lib/sequel/extensions/schema_caching.rb', line 52 def dump_schema_cache(file) File.open(file, 'wb'){|f| f.write(Marshal.dump(@schemas))} nil end |
#dump_schema_cache?(file) ⇒ Boolean
Dump the cached schema to the filename given unless the file already exists.
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# File 'lib/sequel/extensions/schema_caching.rb', line 59 def dump_schema_cache?(file) dump_schema_cache(file) unless File.exist?(file) end |
#dump_schema_migration(options = {}) ⇒ Object
Return a string that contains a Sequel::Migration subclass that when run would recreate the database structure. Options:
-
:same_db - Don’t attempt to translate database types to ruby types. If this isn’t set to true, all database types will be translated to ruby types, but there is no guarantee that the migration generated will yield the same type. Without this set, types that aren’t recognized will be translated to a string-like type.
-
:foreign_keys - If set to false, don’t dump foreign_keys
-
:indexes - If set to false, don’t dump indexes (they can be added later via dump_index_migration).
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# File 'lib/sequel/extensions/schema_dumper.rb', line 56 def dump_schema_migration(={}) = .dup if [:indexes] == false && !.has_key?(:foreign_keys) # Unless foreign_keys option is specifically set, disable if indexes # are disabled, as foreign keys that point to non-primary keys rely # on unique indexes being created first [:foreign_keys] = false end ts = sort_dumped_tables(tables(), ) skipped_fks = if sfk = [:skipped_foreign_keys] # Handle skipped foreign keys by adding them at the end via # alter_table/add_foreign_key. Note that skipped foreign keys # probably result in a broken down migration. sfka = sfk.sort_by{|table, fks| table.to_s}.map{|table, fks| dump_add_fk_constraints(table, fks.values)} sfka.join("\n\n").gsub(/^/o, ' ') unless sfka.empty? end <<END_MIG Sequel.migration do up do #{ts.map{|t| dump_table_schema(t, )}.join("\n\n").gsub(/^/o, ' ')}#{"\n \n" if skipped_fks}#{skipped_fks} end down do drop_table(#{ts.reverse.inspect[1...-1]}) end end END_MIG end |
#dump_table_schema(table, options = {}) ⇒ Object
Return a string with a create table block that will recreate the given table’s schema. Takes the same options as dump_schema_migration.
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# File 'lib/sequel/extensions/schema_dumper.rb', line 89 def dump_table_schema(table, ={}) table = table.value.to_s if table.is_a?(SQL::Identifier) gen = dump_table_generator(table, ) commands = [gen.dump_columns, gen.dump_constraints, gen.dump_indexes].reject{|x| x == ''}.join("\n\n") "create_table(#{table.inspect}#{', :ignore_index_errors=>true' if ![:same_db] && [:indexes] != false && !gen.indexes.empty?}) do\n#{commands.gsub(/^/o, ' ')}\nend" end |
#each_server(&block) ⇒ Object
Yield a new Database instance for every server in the connection pool. Intended for use in sharded environments where there is a need to make schema modifications (DDL queries) on each shard.
DB.each_server{|db| db.create_table(:users){primary_key :id; String :name}}
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# File 'lib/sequel/database/connecting.rb', line 181 def each_server(&block) servers.each{|s| self.class.connect(server_opts(s), &block)} end |
#execute(sql, opts = {}) ⇒ Object
Executes the given SQL on the database. This method should be overridden in descendants. This method should not be called directly by user code.
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# File 'lib/sequel/database/query.rb', line 64 def execute(sql, opts={}) raise NotImplemented, "#execute should be overridden by adapters" end |
#execute_ddl(sql, 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.
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# File 'lib/sequel/database/query.rb', line 71 def execute_ddl(sql, opts={}, &block) execute_dui(sql, opts, &block) end |
#execute_dui(sql, opts = {}, &block) ⇒ Object
Method that should be used when issuing a DELETE, UPDATE, or INSERT statement. By default, calls execute. This method should not be called directly by user code.
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# File 'lib/sequel/database/query.rb', line 78 def execute_dui(sql, opts={}, &block) execute(sql, opts, &block) end |
#execute_insert(sql, 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.
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# File 'lib/sequel/database/query.rb', line 85 def execute_insert(sql, 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.
Examples:
# Introspec 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
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# File 'lib/sequel/database/dataset_defaults.rb', line 89 def extend_datasets(mod=nil, &block) raise(Error, "must provide either mod or block, not both") if mod && block reset_schema_utility_dataset mod = Module.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) end |
#fetch(sql, *args, &block) ⇒ Object
Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch
method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch
can also perform parameterized queries for protection against SQL injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
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# File 'lib/sequel/database/dataset.rb', line 44 def fetch(sql, *args, &block) ds = dataset.with_sql(sql, *args) ds.each(&block) if block ds end |
#foreign_key_list(table, opts = {}) ⇒ Object
Returns an array of hashes containing foreign key information from the table. Each hash will contain at least the following fields:
- :columns
-
An array of columns in the given table
- :table
-
The table referenced by the columns
- :key
-
An array of columns referenced (in the table specified by :table), but can be nil on certain adapters if the primary key is referenced.
The hash may also contain entries for:
- :deferrable
-
Whether the constraint is deferrable
- :name
-
The name of the constraint
- :on_delete
-
The action to take ON DELETE
- :on_update
-
The action to take ON UPDATE
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# File 'lib/sequel/database/query.rb', line 103 def foreign_key_list(table, opts={}) raise NotImplemented, "#foreign_key_list should be overridden by adapters" end |
#from(*args, &block) ⇒ Object
Returns a new dataset with the from
method invoked. If a block is given, it is used as a filter on the dataset.
DB.from(:items) # SELECT * FROM items
DB.from(:items){id > 2} # SELECT * FROM items WHERE (id > 2)
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# File 'lib/sequel/database/dataset.rb', line 55 def from(*args, &block) ds = dataset.from(*args) block ? ds.filter(&block) : ds 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.
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# File 'lib/sequel/database/misc.rb', line 113 def (v) Sequel.(v, timezone) end |
#get(*args, &block) ⇒ Object
Returns a single value from the database, e.g.:
DB.get(1) # SELECT 1
# => 1
DB.get{server_version{}} # SELECT server_version()
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# File 'lib/sequel/database/query.rb', line 112 def get(*args, &block) dataset.get(*args, &block) end |
#identifier_input_method ⇒ Object
The method to call on identifiers going into the database
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# File 'lib/sequel/database/dataset_defaults.rb', line 103 def identifier_input_method case @identifier_input_method when nil @identifier_input_method = @opts.fetch(:identifier_input_method, (@@identifier_input_method.nil? ? identifier_input_method_default : @@identifier_input_method)) @identifier_input_method == "" ? nil : @identifier_input_method when "" nil else @identifier_input_method end end |
#identifier_input_method=(v) ⇒ Object
Set the method to call on identifiers going into the database:
DB[:items] # SELECT * FROM items
DB.identifier_input_method = :upcase
DB[:items] # SELECT * FROM ITEMS
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# File 'lib/sequel/database/dataset_defaults.rb', line 120 def identifier_input_method=(v) reset_schema_utility_dataset @identifier_input_method = v || "" end |
#identifier_output_method ⇒ Object
The method to call on identifiers coming from the database
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# File 'lib/sequel/database/dataset_defaults.rb', line 126 def identifier_output_method case @identifier_output_method when nil @identifier_output_method = @opts.fetch(:identifier_output_method, (@@identifier_output_method.nil? ? identifier_output_method_default : @@identifier_output_method)) @identifier_output_method == "" ? nil : @identifier_output_method when "" nil else @identifier_output_method end end |
#identifier_output_method=(v) ⇒ Object
Set the method to call on identifiers coming from the database:
DB[:items].first # {:id=>1, :name=>'foo'}
DB.identifier_output_method = :upcase
DB[:items].first # {:ID=>1, :NAME=>'foo'}
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# File 'lib/sequel/database/dataset_defaults.rb', line 143 def identifier_output_method=(v) reset_schema_utility_dataset @identifier_output_method = v || "" end |
#in_transaction?(opts = {}) ⇒ Boolean
Return true if already in a transaction given the options, false otherwise. Respects the :server option for selecting a shard.
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# File 'lib/sequel/database/misc.rb', line 120 def in_transaction?(opts={}) synchronize(opts[:server]){|conn| !!_trans(conn)} end |
#indexes(table, opts = {}) ⇒ Object
Return a hash containing index information for the table. Hash keys are index name symbols. Values are subhashes with two keys, :columns and :unique. The value of :columns is an array of symbols of column names. The value of :unique is true or false depending on if the index is unique.
Should not include the primary key index, functional indexes, or partial indexes.
DB.indexes(:artists)
# => {:artists_name_ukey=>{:columns=>[:name], :unique=>true}}
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# File 'lib/sequel/database/query.rb', line 125 def indexes(table, opts={}) raise NotImplemented, "#indexes should be overridden by adapters" end |
#inspect ⇒ Object
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
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# File 'lib/sequel/database/misc.rb', line 126 def inspect a = [] a << uri.inspect if uri if (oo = opts[:orig_opts]) && !oo.empty? a << oo.inspect end "#<#{self.class}: #{a.join(' ')}>" end |
#literal(v) ⇒ Object
Proxy the literal call to the dataset.
DB.literal(1) # 1
DB.literal(:a) # a
DB.literal('a') # 'a'
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# File 'lib/sequel/database/misc.rb', line 140 def literal(v) schema_utility_dataset.literal(v) end |
#load_schema_cache(file) ⇒ Object
Replace the schema cache with the data from the given file, which should be in Marshal format.
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# File 'lib/sequel/extensions/schema_caching.rb', line 65 def load_schema_cache(file) @schemas = Marshal.load(File.read(file)) nil end |
#load_schema_cache?(file) ⇒ Boolean
Replace the schema cache with the data from the given file if the file exists.
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# File 'lib/sequel/extensions/schema_caching.rb', line 72 def load_schema_cache?(file) load_schema_cache(file) if File.exist?(file) end |
#log_exception(exception, message) ⇒ Object
Log a message at error level, with information about the exception.
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# File 'lib/sequel/database/logging.rb', line 21 def log_exception(exception, ) log_each(:error, "#{exception.class}: #{exception..strip}: #{}") end |
#log_info(message, args = nil) ⇒ Object
Log a message at level info to all loggers.
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# File 'lib/sequel/database/logging.rb', line 26 def log_info(, args=nil) log_each(:info, args ? "#{}; #{args.inspect}" : ) end |
#log_yield(sql, 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.
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# File 'lib/sequel/database/logging.rb', line 32 def log_yield(sql, args=nil) return yield if @loggers.empty? sql = "#{sql}; #{args.inspect}" if args start = Time.now begin yield rescue => e log_exception(e, sql) raise ensure log_duration(Time.now - start, sql) unless e end end |
#logger=(logger) ⇒ Object
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
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# File 'lib/sequel/database/logging.rb', line 49 def logger=(logger) @loggers = Array(logger) end |
#prepared_statement(name) ⇒ Object
Synchronize access to the prepared statements cache.
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# File 'lib/sequel/database/misc.rb', line 145 def prepared_statement(name) Sequel.synchronize{prepared_statements[name]} end |
#query(&block) ⇒ Object
Return a dataset modified by the query block
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# File 'lib/sequel/extensions/query.rb', line 8 def query(&block) dataset.query(&block) end |
#quote_identifiers=(v) ⇒ Object
Set whether to quote identifiers (columns and tables) for this database:
DB[:items] # SELECT * FROM items
DB.quote_identifiers = true
DB[:items] # SELECT * FROM "items"
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# File 'lib/sequel/database/dataset_defaults.rb', line 153 def quote_identifiers=(v) reset_schema_utility_dataset @quote_identifiers = v end |
#quote_identifiers? ⇒ Boolean
Returns true if the database quotes identifiers.
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# File 'lib/sequel/database/dataset_defaults.rb', line 159 def quote_identifiers? return @quote_identifiers unless @quote_identifiers.nil? @quote_identifiers = @opts.fetch(:quote_identifiers, (@@quote_identifiers.nil? ? quote_identifiers_default : @@quote_identifiers)) end |
#remove_servers(*servers) ⇒ Object
Dynamically remove existing servers from the connection pool. Intended for use with master/slave or shard configurations where it is useful to remove existing server hosts at runtime.
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)
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# File 'lib/sequel/database/connecting.rb', line 195 def remove_servers(*servers) if h = @opts[:servers] servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} @pool.remove_servers(servers) end 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
.
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# File 'lib/sequel/database/schema_methods.rb', line 293 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]
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# File 'lib/sequel/database/schema_methods.rb', line 281 def rename_table(name, new_name) execute_ddl(rename_table_sql(name, new_name)) remove_cached_schema(name) nil end |
#run(sql, 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")
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# File 'lib/sequel/database/query.rb', line 134 def run(sql, opts={}) execute_ddl(sql, opts) nil end |
#schema(table, 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 should hash at least contain 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.
- :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}]]
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# File 'lib/sequel/database/query.rb', line 179 def schema(table, opts={}) raise(Error, 'schema parsing is not implemented on this database') unless respond_to?(:schema_parse_table, true) opts = opts.dup 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) tab = table.first_source_table sch, table_name = schema_and_table(tab) quoted_name = table.literal(tab) opts[:dataset] = table else sch, table_name = schema_and_table(table) quoted_name = quote_schema_table(table) end opts[:schema] = sch if sch && !opts.include?(:schema) Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] return Sequel.synchronize{@schemas[quoted_name]} if @schemas[quoted_name] cols = schema_parse_table(table_name, opts) raise(Error, 'schema parsing returned no columns, table probably doesn\'t exist') if cols.nil? || cols.empty? cols.each{|_,c| c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type])} Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema cols end |
#select(*args, &block) ⇒ Object
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1
DB.select{server_version{}} # SELECT server_version()
DB.select(:id).from(:items) # SELECT id FROM items
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# File 'lib/sequel/database/dataset.rb', line 65 def select(*args, &block) dataset.select(*args, &block) end |
#serial_primary_key_options ⇒ Object
Default serial primary key options, used by the table creation code.
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# File 'lib/sequel/database/misc.rb', line 151 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]
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# File 'lib/sequel/database/connecting.rb', line 206 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
.
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# File 'lib/sequel/database/schema_methods.rb', line 302 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
.
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# File 'lib/sequel/database/schema_methods.rb', line 311 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.
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# File 'lib/sequel/database/misc.rb', line 156 def set_prepared_statement(name, ps) Sequel.synchronize{prepared_statements[name] = ps} end |
#single_threaded? ⇒ Boolean
Returns true if the database is using a single-threaded connection pool.
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# File 'lib/sequel/database/connecting.rb', line 211 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.
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# File 'lib/sequel/database/misc.rb', line 162 def supports_create_table_if_not_exists? false end |
#supports_drop_table_if_exists? ⇒ Boolean
Whether the database supports DROP TABLE IF EXISTS syntax, default is the same as #supports_create_table_if_not_exists?.
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# File 'lib/sequel/database/misc.rb', line 168 def supports_drop_table_if_exists? supports_create_table_if_not_exists? end |
#supports_prepared_transactions? ⇒ Boolean
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
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# File 'lib/sequel/database/misc.rb', line 174 def supports_prepared_transactions? false end |
#supports_savepoints? ⇒ Boolean
Whether the database and adapter support savepoints, false by default.
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# File 'lib/sequel/database/misc.rb', line 179 def supports_savepoints? false end |
#supports_savepoints_in_prepared_transactions? ⇒ Boolean
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), default is false.
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# File 'lib/sequel/database/misc.rb', line 185 def supports_savepoints_in_prepared_transactions? supports_prepared_transactions? && supports_savepoints? end |
#supports_transaction_isolation_levels? ⇒ Boolean
Whether the database and adapter support transaction isolation levels, false by default.
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# File 'lib/sequel/database/misc.rb', line 190 def supports_transaction_isolation_levels? false end |
#supports_transactional_ddl? ⇒ Boolean
Whether DDL statements work correctly in transactions, false by default.
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# File 'lib/sequel/database/misc.rb', line 195 def supports_transactional_ddl? false 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
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# File 'lib/sequel/database/connecting.rb', line 228 def synchronize(server=nil) @pool.hold(server || :default){|conn| yield conn} 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.
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# File 'lib/sequel/database/query.rb', line 215 def table_exists?(name) sch, table_name = schema_and_table(name) name = SQL::QualifiedIdentifier.new(sch, table_name) if sch _table_exists?(from(name)) true rescue DatabaseError false end |
#tables(opts = {}) ⇒ Object
Return all tables in the database as an array of symbols.
DB.tables # => [:albums, :artists]
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# File 'lib/sequel/database/query.rb', line 227 def tables(opts={}) raise NotImplemented, "#tables should be overridden by adapters" 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.
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# File 'lib/sequel/database/connecting.rb', line 241 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.
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# File 'lib/sequel/database/misc.rb', line 207 def (v) Sequel.(v, timezone) end |
#transaction(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 tabels do not support transactions.
The following options are respected:
- :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.
- :prepare
-
A string to use as the transaction identifier for a prepared transaction (two-phase commit), if the database/adapter supports prepared transactions.
- :rollback
-
Can the 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.
- :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.
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# File 'lib/sequel/database/query.rb', line 252 def transaction(opts={}, &block) synchronize(opts[:server]) do |conn| return yield(conn) if already_in_transaction?(conn, opts) _transaction(conn, opts, &block) 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.
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# File 'lib/sequel/database/misc.rb', line 216 def typecast_value(column_type, value) return nil if value.nil? meth = "typecast_value_#{column_type}" begin 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.
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# File 'lib/sequel/database/misc.rb', line 228 def uri opts[:uri] end |
#url ⇒ Object
Explicit alias of uri for easier subclassing.
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# File 'lib/sequel/database/misc.rb', line 233 def url uri end |
#views(opts = {}) ⇒ Object
Return all views in the database as an array of symbols.
DB.views # => [:gold_albums, :artists_with_many_albums]
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# File 'lib/sequel/database/query.rb', line 262 def views(opts={}) raise NotImplemented, "#views should be overridden by adapters" end |