Class: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
- Inherits:
-
AbstractAdapter
- Object
- AbstractAdapter
- ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
- Defined in:
- lib/active_record/connection_adapters/postgresql_adapter.rb
Overview
The PostgreSQL adapter works both with the native C (ruby.scripting.ca/postgres/) and the pure Ruby (available both as gem and from rubyforge.org/frs/?group_id=234&release_id=1944) drivers.
Options:
-
:host
- Defaults to “localhost”. -
:port
- Defaults to 5432. -
:username
- Defaults to nothing. -
:password
- Defaults to nothing. -
:database
- The name of the database. No default, must be provided. -
:schema_search_path
- An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the:schema_order
option. -
:encoding
- An optional client encoding that is used in aSET client_encoding TO <encoding>
call on the connection. -
:min_messages
- An optional client min messages that is used in aSET client_min_messages TO <min_messages>
call on the connection. -
:allow_concurrency
- If true, use async query methods so Ruby threads don’t deadlock; otherwise, use blocking query methods.
Constant Summary collapse
- ADAPTER_NAME =
'PostgreSQL'.freeze
- NATIVE_DATABASE_TYPES =
{ :primary_key => "serial primary key".freeze, :string => { :name => "character varying", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "integer" }, :float => { :name => "float" }, :decimal => { :name => "decimal" }, :datetime => { :name => "timestamp" }, :timestamp => { :name => "timestamp" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "bytea" }, :boolean => { :name => "boolean" }, :xml => { :name => "xml" } }
Instance Attribute Summary
Attributes included from QueryCache
#query_cache, #query_cache_enabled
Instance Method Summary collapse
-
#active? ⇒ Boolean
Is this connection alive and ready for queries?.
-
#adapter_name ⇒ Object
Returns ‘PostgreSQL’ as adapter name for identification purposes.
-
#add_column(table_name, column_name, type, options = {}) ⇒ Object
Adds a new column to the named table.
-
#begin_db_transaction ⇒ Object
Begins a transaction.
-
#change_column(table_name, column_name, type, options = {}) ⇒ Object
Changes the column of a table.
-
#change_column_default(table_name, column_name, default) ⇒ Object
Changes the default value of a table column.
- #change_column_null(table_name, column_name, null, default = nil) ⇒ Object
-
#client_min_messages ⇒ Object
Returns the current client message level.
-
#client_min_messages=(level) ⇒ Object
Set the client message level.
-
#columns(table_name, name = nil) ⇒ Object
Returns the list of all column definitions for a table.
-
#commit_db_transaction ⇒ Object
Commits a transaction.
-
#create_database(name, options = {}) ⇒ Object
Create a new PostgreSQL database.
- #create_savepoint ⇒ Object
-
#current_database ⇒ Object
Returns the current database name.
-
#default_sequence_name(table_name, pk = nil) ⇒ Object
Returns the sequence name for a table’s primary key or some other specified key.
-
#disable_referential_integrity ⇒ Object
:nodoc:.
-
#disconnect! ⇒ Object
Close the connection.
-
#distinct(columns, order_by) ⇒ Object
Returns a SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.
-
#drop_database(name) ⇒ Object
Drops a PostgreSQL database.
-
#encoding ⇒ Object
Returns the current database encoding format.
-
#escape_bytea(value) ⇒ Object
Escapes binary strings for bytea input to the database.
-
#execute(sql, name = nil) ⇒ Object
Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.
- #index_name_length ⇒ Object
-
#indexes(table_name, name = nil) ⇒ Object
Returns the list of all indexes for a table.
-
#initialize(connection, logger, connection_parameters, config) ⇒ PostgreSQLAdapter
constructor
Initializes and connects a PostgreSQL adapter.
-
#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object
(also: #create)
Executes an INSERT query and returns the new record’s ID.
-
#native_database_types ⇒ Object
:nodoc:.
- #outside_transaction? ⇒ Boolean
-
#pk_and_sequence_for(table) ⇒ Object
Returns a table’s primary key and belonging sequence.
-
#primary_key(table) ⇒ Object
Returns just a table’s primary key.
-
#query(sql, name = nil) ⇒ Object
Queries the database and returns the results in an Array-like object.
-
#quote(value, column = nil) ⇒ Object
Quotes PostgreSQL-specific data types for SQL input.
-
#quote_column_name(name) ⇒ Object
Quotes column names for use in SQL queries.
-
#quote_string(s) ⇒ Object
Quotes strings for use in SQL input.
-
#quote_table_name(name) ⇒ Object
Checks the following cases:.
-
#quoted_date(value) ⇒ Object
Quote date/time values for use in SQL input.
-
#reconnect! ⇒ Object
Close then reopen the connection.
-
#recreate_database(name) ⇒ Object
SCHEMA STATEMENTS ========================================.
- #release_savepoint ⇒ Object
-
#remove_index!(table_name, index_name) ⇒ Object
:nodoc:.
-
#rename_column(table_name, column_name, new_column_name) ⇒ Object
Renames a column in a table.
-
#rename_table(name, new_name) ⇒ Object
Renames a table.
-
#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object
Resets the sequence of a table’s primary key to the maximum value.
-
#result_as_array(res) ⇒ Object
create a 2D array representing the result set.
-
#rollback_db_transaction ⇒ Object
Aborts a transaction.
- #rollback_to_savepoint ⇒ Object
-
#schema_search_path ⇒ Object
Returns the active schema search path.
-
#schema_search_path=(schema_csv) ⇒ Object
Sets the schema search path to a string of comma-separated schema names.
-
#select_rows(sql, name = nil) ⇒ Object
Executes a SELECT query and returns an array of rows.
-
#set_standard_conforming_strings ⇒ Object
Enable standard-conforming strings if available.
- #supports_ddl_transactions? ⇒ Boolean
-
#supports_disable_referential_integrity? ⇒ Boolean
REFERENTIAL INTEGRITY ====================================.
- #supports_insert_with_returning? ⇒ Boolean
-
#supports_migrations? ⇒ Boolean
Does PostgreSQL support migrations?.
-
#supports_primary_key? ⇒ Boolean
Does PostgreSQL support finding primary key on non-Active Record tables?.
- #supports_savepoints? ⇒ Boolean
-
#table_alias_length ⇒ Object
Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.
- #table_exists?(name) ⇒ Boolean
-
#tables(name = nil) ⇒ Object
Returns the list of all tables in the schema search path or a specified schema.
-
#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object
Maps logical Rails types to PostgreSQL-specific data types.
-
#unescape_bytea(value) ⇒ Object
Unescapes bytea output from a database to the binary string it represents.
-
#update_sql(sql, name = nil) ⇒ Object
Executes an UPDATE query and returns the number of affected tuples.
Methods inherited from AbstractAdapter
#current_savepoint_name, #decrement_open_transactions, #ids_in_list_limit, #increment_open_transactions, #open_transactions, #prefetch_primary_key?, #raw_connection, #requires_reloading?, #reset!, #supports_count_distinct?, #transaction_joinable=, #verify!
Methods included from QueryCache
#cache, #clear_query_cache, dirties_query_cache, included, #select_all, #uncached
Methods included from DatabaseLimits
#column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_name_length
Methods included from Quoting
Methods included from DatabaseStatements
#add_limit_offset!, #add_transaction_record, #case_sensitive_equality_operator, #delete, #empty_insert_statement_value, #insert_fixture, #limited_update_conditions, #reset_sequence!, #sanitize_limit, #select_all, #select_one, #select_value, #select_values, #transaction, #update
Methods included from SchemaStatements
#add_column_options!, #add_index, #add_timestamps, #assume_migrated_upto_version, #change_table, #column_exists?, #create_table, #drop_table, #dump_schema_information, #index_exists?, #index_name, #index_name_exists?, #initialize_schema_migrations_table, #remove_column, #remove_index, #remove_timestamps, #rename_index, #structure_dump, #table_alias_for
Constructor Details
#initialize(connection, logger, connection_parameters, config) ⇒ PostgreSQLAdapter
Initializes and connects a PostgreSQL adapter.
237 238 239 240 241 242 243 244 245 246 247 248 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 237 def initialize(connection, logger, connection_parameters, config) super(connection, logger) @connection_parameters, @config = connection_parameters, config # @local_tz is initialized as nil to avoid warnings when connect tries to use it @local_tz = nil @table_alias_length = nil @postgresql_version = nil connect @local_tz = execute('SHOW TIME ZONE').first["TimeZone"] end |
Instance Method Details
#active? ⇒ Boolean
Is this connection alive and ready for queries?
251 252 253 254 255 256 257 258 259 260 261 262 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 251 def active? if @connection.respond_to?(:status) @connection.status == PGconn::CONNECTION_OK else # We're asking the driver, not Active Record, so use @connection.query instead of #query @connection.query 'SELECT 1' true end # postgres-pr raises a NoMethodError when querying if no connection is available. rescue PGError, NoMethodError false end |
#adapter_name ⇒ Object
Returns ‘PostgreSQL’ as adapter name for identification purposes.
232 233 234 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 232 def adapter_name ADAPTER_NAME end |
#add_column(table_name, column_name, type, options = {}) ⇒ Object
Adds a new column to the named table. See TableDefinition#column for details of the options you can use.
813 814 815 816 817 818 819 820 821 822 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 813 def add_column(table_name, column_name, type, = {}) default = [:default] notnull = [:null] == false # Add the column. execute("ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, [:limit], [:precision], [:scale])}") change_column_default(table_name, column_name, default) if () change_column_null(table_name, column_name, false, default) if notnull end |
#begin_db_transaction ⇒ Object
Begins a transaction.
529 530 531 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 529 def begin_db_transaction execute "BEGIN" end |
#change_column(table_name, column_name, type, options = {}) ⇒ Object
Changes the column of a table.
825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 825 def change_column(table_name, column_name, type, = {}) quoted_table_name = quote_table_name(table_name) begin execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, [:limit], [:precision], [:scale])}" rescue ActiveRecord::StatementInvalid => e raise e if postgresql_version > 80000 # This is PostgreSQL 7.x, so we have to use a more arcane way of doing it. begin begin_db_transaction tmp_column_name = "#{column_name}_ar_tmp" add_column(table_name, tmp_column_name, type, ) execute "UPDATE #{quoted_table_name} SET #{quote_column_name(tmp_column_name)} = CAST(#{quote_column_name(column_name)} AS #{type_to_sql(type, [:limit], [:precision], [:scale])})" remove_column(table_name, column_name) rename_column(table_name, tmp_column_name, column_name) commit_db_transaction rescue rollback_db_transaction end end change_column_default(table_name, column_name, [:default]) if () change_column_null(table_name, column_name, [:null], [:default]) if .key?(:null) end |
#change_column_default(table_name, column_name, default) ⇒ Object
Changes the default value of a table column.
851 852 853 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 851 def change_column_default(table_name, column_name, default) execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}" end |
#change_column_null(table_name, column_name, null, default = nil) ⇒ Object
855 856 857 858 859 860 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 855 def change_column_null(table_name, column_name, null, default = nil) unless null || default.nil? execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL") end execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL") end |
#client_min_messages ⇒ Object
Returns the current client message level.
716 717 718 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 716 def query('SHOW client_min_messages')[0][0] end |
#client_min_messages=(level) ⇒ Object
Set the client message level.
721 722 723 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 721 def (level) execute("SET client_min_messages TO '#{level}'") end |
#columns(table_name, name = nil) ⇒ Object
Returns the list of all column definitions for a table.
678 679 680 681 682 683 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 678 def columns(table_name, name = nil) # Limit, precision, and scale are all handled by the superclass. column_definitions(table_name).collect do |name, type, default, notnull| PostgreSQLColumn.new(name, default, type, notnull == 'f') end end |
#commit_db_transaction ⇒ Object
Commits a transaction.
534 535 536 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 534 def commit_db_transaction execute "COMMIT" end |
#create_database(name, options = {}) ⇒ Object
Create a new PostgreSQL database. Options include :owner
, :template
, :encoding
, :tablespace
, and :connection_limit
(note that MySQL uses :charset
while PostgreSQL uses :encoding
).
Example:
create_database config[:database], config
create_database 'foo_development', :encoding => 'unicode'
573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 573 def create_database(name, = {}) = .reverse_merge(:encoding => "utf8") option_string = .symbolize_keys.sum do |key, value| case key when :owner " OWNER = \"#{value}\"" when :template " TEMPLATE = \"#{value}\"" when :encoding " ENCODING = '#{value}'" when :tablespace " TABLESPACE = \"#{value}\"" when :connection_limit " CONNECTION LIMIT = #{value}" else "" end end execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}" end |
#create_savepoint ⇒ Object
547 548 549 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 547 def create_savepoint execute("SAVEPOINT #{current_savepoint_name}") end |
#current_database ⇒ Object
Returns the current database name.
686 687 688 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 686 def current_database query('select current_database()')[0][0] end |
#default_sequence_name(table_name, pk = nil) ⇒ Object
Returns the sequence name for a table’s primary key or some other specified key.
726 727 728 729 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 726 def default_sequence_name(table_name, pk = nil) #:nodoc: default_pk, default_seq = pk_and_sequence_for(table_name) default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq" end |
#disable_referential_integrity ⇒ Object
:nodoc:
405 406 407 408 409 410 411 412 413 414 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 405 def disable_referential_integrity #:nodoc: if supports_disable_referential_integrity?() then execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} DISABLE TRIGGER ALL" }.join(";")) end yield ensure if supports_disable_referential_integrity?() then execute(tables.collect { |name| "ALTER TABLE #{quote_table_name(name)} ENABLE TRIGGER ALL" }.join(";")) end end |
#disconnect! ⇒ Object
Close the connection.
276 277 278 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 276 def disconnect! @connection.close rescue nil end |
#distinct(columns, order_by) ⇒ Object
Returns a SELECT DISTINCT clause for a given set of columns and a given ORDER BY clause.
PostgreSQL requires the ORDER BY columns in the select list for distinct queries, and requires that the ORDER BY include the distinct column.
distinct("posts.id", "posts.created_at desc")
894 895 896 897 898 899 900 901 902 903 904 905 906 907 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 894 def distinct(columns, order_by) #:nodoc: return "DISTINCT #{columns}" if order_by.blank? # Construct a clean list of column names from the ORDER BY clause, removing # any ASC/DESC modifiers order_columns = order_by.split(',').collect { |s| s.split.first } order_columns.delete_if { |c| c.blank? } order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" } # Return a DISTINCT ON() clause that's distinct on the columns we want but includes # all the required columns for the ORDER BY to work properly. sql = "DISTINCT ON (#{columns}) #{columns}, " sql << order_columns * ', ' end |
#drop_database(name) ⇒ Object
Drops a PostgreSQL database
Example:
drop_database 'matt_development'
600 601 602 603 604 605 606 607 608 609 610 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 600 def drop_database(name) #:nodoc: if postgresql_version >= 80200 execute "DROP DATABASE IF EXISTS #{quote_table_name(name)}" else begin execute "DROP DATABASE #{quote_table_name(name)}" rescue ActiveRecord::StatementInvalid @logger.warn "#{name} database doesn't exist." if @logger end end end |
#encoding ⇒ Object
Returns the current database encoding format.
691 692 693 694 695 696 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 691 def encoding query(<<-end_sql)[0][0] SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database WHERE pg_database.datname LIKE '#{current_database}' end_sql end |
#escape_bytea(value) ⇒ Object
Escapes binary strings for bytea input to the database.
323 324 325 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 323 def escape_bytea(value) @connection.escape_bytea(value) if value end |
#execute(sql, name = nil) ⇒ Object
Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.
513 514 515 516 517 518 519 520 521 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 513 def execute(sql, name = nil) log(sql, name) do if @async @connection.async_exec(sql) else @connection.exec(sql) end end end |
#index_name_length ⇒ Object
871 872 873 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 871 def index_name_length 63 end |
#indexes(table_name, name = nil) ⇒ Object
Returns the list of all indexes for a table.
644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 644 def indexes(table_name, name = nil) schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',') result = query(<<-SQL, name) SELECT distinct i.relname, d.indisunique, d.indkey, t.oid FROM pg_class t, pg_class i, pg_index d WHERE i.relkind = 'i' AND d.indexrelid = i.oid AND d.indisprimary = 'f' AND t.oid = d.indrelid AND t.relname = '#{table_name}' AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (#{schemas}) ) ORDER BY i.relname SQL result.map do |row| index_name = row[0] unique = row[1] == 't' indkey = row[2].split(" ") oid = row[3] columns = Hash[query(<<-SQL, "Columns for index #{row[0]} on #{table_name}")] SELECT a.attnum, a.attname FROM pg_attribute a WHERE a.attrelid = #{oid} AND a.attnum IN (#{indkey.join(",")}) SQL column_names = columns.values_at(*indkey).compact column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names) end.compact end |
#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object Also known as: create
Executes an INSERT query and returns the new record’s ID
425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 425 def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) # Extract the table from the insert sql. Yuck. table = sql.split(" ", 4)[2].gsub('"', '') # Try an insert with 'returning id' if available (PG >= 8.2) if supports_insert_with_returning? pk, sequence_name = *pk_and_sequence_for(table) unless pk if pk id = select_value("#{sql} RETURNING #{quote_column_name(pk)}") clear_query_cache return id end end # Otherwise, insert then grab last_insert_id. if insert_id = super insert_id else # If neither pk nor sequence name is given, look them up. unless pk || sequence_name pk, sequence_name = *pk_and_sequence_for(table) end # If a pk is given, fallback to default sequence name. # Don't fetch last insert id for a table without a pk. if pk && sequence_name ||= default_sequence_name(table, pk) last_insert_id(table, sequence_name) end end end |
#native_database_types ⇒ Object
:nodoc:
280 281 282 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 280 def native_database_types #:nodoc: NATIVE_DATABASE_TYPES end |
#outside_transaction? ⇒ Boolean
543 544 545 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 543 def outside_transaction? @connection.transaction_status == PGconn::PQTRANS_IDLE end |
#pk_and_sequence_for(table) ⇒ Object
Returns a table’s primary key and belonging sequence.
752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 752 def pk_and_sequence_for(table) #:nodoc: # First try looking for a sequence with a dependency on the # given table's primary key. result = query(<<-end_sql, 'PK and serial sequence')[0] SELECT attr.attname, seq.relname FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons WHERE seq.oid = dep.objid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND cons.contype = 'p' AND dep.refobjid = '#{quote_table_name(table)}'::regclass end_sql if result.nil? or result.empty? # If that fails, try parsing the primary key's default value. # Support the 7.x and 8.0 nextval('foo'::text) as well as # the 8.1+ nextval('foo'::regclass). result = query(<<-end_sql, 'PK and custom sequence')[0] SELECT attr.attname, CASE WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN substr(split_part(def.adsrc, '''', 2), strpos(split_part(def.adsrc, '''', 2), '.')+1) ELSE split_part(def.adsrc, '''', 2) END FROM pg_class t JOIN pg_attribute attr ON (t.oid = attrelid) JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum) JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1]) WHERE t.oid = '#{quote_table_name(table)}'::regclass AND cons.contype = 'p' AND def.adsrc ~* 'nextval' end_sql end # [primary_key, sequence] [result.first, result.last] rescue nil end |
#primary_key(table) ⇒ Object
Returns just a table’s primary key
801 802 803 804 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 801 def primary_key(table) pk_and_sequence = pk_and_sequence_for(table) pk_and_sequence && pk_and_sequence.first end |
#query(sql, name = nil) ⇒ Object
Queries the database and returns the results in an Array-like object
500 501 502 503 504 505 506 507 508 509 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 500 def query(sql, name = nil) #:nodoc: log(sql, name) do if @async res = @connection.async_exec(sql) else res = @connection.exec(sql) end return result_as_array(res) end end |
#quote(value, column = nil) ⇒ Object
Quotes PostgreSQL-specific data types for SQL input.
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 335 def quote(value, column = nil) #:nodoc: return super unless column if value.kind_of?(String) && column.type == :binary "'#{escape_bytea(value)}'" elsif Float === value && column.type == :datetime return super unless value.infinite? "'#{value.to_s.downcase}'" elsif value.kind_of?(String) && column.sql_type == 'xml' "xml '#{quote_string(value)}'" elsif value.kind_of?(Numeric) && column.sql_type == 'money' # Not truly string input, so doesn't require (or allow) escape string syntax. "'#{value}'" elsif value.kind_of?(String) && column.sql_type =~ /^bit/ case value when /^[01]*$/ "B'#{value}'" # Bit-string notation when /^[0-9A-F]*$/i "X'#{value}'" # Hexadecimal notation end else super end end |
#quote_column_name(name) ⇒ Object
Quotes column names for use in SQL queries.
385 386 387 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 385 def quote_column_name(name) #:nodoc: PGconn.quote_ident(name.to_s) end |
#quote_string(s) ⇒ Object
Quotes strings for use in SQL input.
361 362 363 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 361 def quote_string(s) #:nodoc: @connection.escape(s) end |
#quote_table_name(name) ⇒ Object
Checks the following cases:
-
table_name
-
“table.name”
-
schema_name.table_name
-
schema_name.“table.name”
-
“schema.name”.table_name
-
“schema.name”.“table.name”
373 374 375 376 377 378 379 380 381 382 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 373 def quote_table_name(name) schema, name_part = extract_pg_identifier_from_name(name.to_s) unless name_part quote_column_name(schema) else table_name, name_part = extract_pg_identifier_from_name(name_part) "#{quote_column_name(schema)}.#{quote_column_name(table_name)}" end end |
#quoted_date(value) ⇒ Object
Quote date/time values for use in SQL input. Includes microseconds if the value is a Time responding to usec.
391 392 393 394 395 396 397 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 391 def quoted_date(value) #:nodoc: if value.acts_like?(:time) && value.respond_to?(:usec) "#{super}.#{sprintf("%06d", value.usec)}" else super end end |
#reconnect! ⇒ Object
Close then reopen the connection.
265 266 267 268 269 270 271 272 273 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 265 def reconnect! if @connection.respond_to?(:reset) @connection.reset configure_connection else disconnect! connect end end |
#recreate_database(name) ⇒ Object
SCHEMA STATEMENTS ========================================
561 562 563 564 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 561 def recreate_database(name) #:nodoc: drop_database(name) create_database(name) end |
#release_savepoint ⇒ Object
555 556 557 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 555 def release_savepoint execute("RELEASE SAVEPOINT #{current_savepoint_name}") end |
#remove_index!(table_name, index_name) ⇒ Object
:nodoc:
867 868 869 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 867 def remove_index!(table_name, index_name) #:nodoc: execute "DROP INDEX #{quote_table_name(index_name)}" end |
#rename_column(table_name, column_name, new_column_name) ⇒ Object
Renames a column in a table.
863 864 865 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 863 def rename_column(table_name, column_name, new_column_name) execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}" end |
#rename_table(name, new_name) ⇒ Object
Renames a table.
807 808 809 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 807 def rename_table(name, new_name) execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}" end |
#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object
Resets the sequence of a table’s primary key to the maximum value.
732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 732 def reset_pk_sequence!(table, pk = nil, sequence = nil) #:nodoc: unless pk and sequence default_pk, default_sequence = pk_and_sequence_for(table) pk ||= default_pk sequence ||= default_sequence end if pk if sequence quoted_sequence = quote_column_name(sequence) select_value <<-end_sql, 'Reset sequence' SELECT setval('#{quoted_sequence}', (SELECT COALESCE(MAX(#{quote_column_name pk})+(SELECT increment_by FROM #{quoted_sequence}), (SELECT min_value FROM #{quoted_sequence})) FROM #{quote_table_name(table)}), false) end_sql else @logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger end end end |
#result_as_array(res) ⇒ Object
create a 2D array representing the result set
458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 458 def result_as_array(res) #:nodoc: # check if we have any binary column and if they need escaping unescape_col = [] res.nfields.times do |j| unescape_col << res.ftype(j) end ary = [] res.ntuples.times do |i| ary << [] res.nfields.times do |j| data = res.getvalue(i,j) case unescape_col[j] # unescape string passed BYTEA field (OID == 17) when BYTEA_COLUMN_TYPE_OID data = unescape_bytea(data) if String === data # If this is a money type column and there are any currency symbols, # then strip them off. Indeed it would be prettier to do this in # PostgreSQLColumn.string_to_decimal but would break form input # fields that call value_before_type_cast. when MONEY_COLUMN_TYPE_OID # Because money output is formatted according to the locale, there are two # cases to consider (note the decimal separators): # (1) $12,345,678.12 # (2) $12.345.678,12 case data when /^-?\D+[\d,]+\.\d{2}$/ # (1) data.gsub!(/[^-\d\.]/, '') when /^-?\D+[\d\.]+,\d{2}$/ # (2) data.gsub!(/[^-\d,]/, '').sub!(/,/, '.') end end ary[i] << data end end return ary end |
#rollback_db_transaction ⇒ Object
Aborts a transaction.
539 540 541 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 539 def rollback_db_transaction execute "ROLLBACK" end |
#rollback_to_savepoint ⇒ Object
551 552 553 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 551 def rollback_to_savepoint execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}") end |
#schema_search_path ⇒ Object
Returns the active schema search path.
711 712 713 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 711 def schema_search_path @schema_search_path ||= query('SHOW search_path')[0][0] end |
#schema_search_path=(schema_csv) ⇒ Object
Sets the schema search path to a string of comma-separated schema names. Names beginning with $ have to be quoted (e.g. $user => ‘$user’). See: www.postgresql.org/docs/current/static/ddl-schemas.html
This should be not be called manually but set in database.yml.
703 704 705 706 707 708 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 703 def schema_search_path=(schema_csv) if schema_csv execute "SET search_path TO #{schema_csv}" @schema_search_path = schema_csv end end |
#select_rows(sql, name = nil) ⇒ Object
Executes a SELECT query and returns an array of rows. Each row is an array of field values.
420 421 422 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 420 def select_rows(sql, name = nil) select_raw(sql, name).last end |
#set_standard_conforming_strings ⇒ Object
Enable standard-conforming strings if available.
295 296 297 298 299 300 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 295 def set_standard_conforming_strings old, self. = , 'panic' execute('SET standard_conforming_strings = on') rescue nil ensure self. = old end |
#supports_ddl_transactions? ⇒ Boolean
306 307 308 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 306 def supports_ddl_transactions? true end |
#supports_disable_referential_integrity? ⇒ Boolean
REFERENTIAL INTEGRITY ====================================
401 402 403 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 401 def supports_disable_referential_integrity?() #:nodoc: postgresql_version >= 80100 end |
#supports_insert_with_returning? ⇒ Boolean
302 303 304 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 302 def supports_insert_with_returning? postgresql_version >= 80200 end |
#supports_migrations? ⇒ Boolean
Does PostgreSQL support migrations?
285 286 287 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 285 def supports_migrations? true end |
#supports_primary_key? ⇒ Boolean
Does PostgreSQL support finding primary key on non-Active Record tables?
290 291 292 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 290 def supports_primary_key? #:nodoc: true end |
#supports_savepoints? ⇒ Boolean
310 311 312 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 310 def supports_savepoints? true end |
#table_alias_length ⇒ Object
Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.
316 317 318 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 316 def table_alias_length @table_alias_length ||= (postgresql_version >= 80000 ? query('SHOW max_identifier_length')[0][0].to_i : 63) end |
#table_exists?(name) ⇒ Boolean
621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 621 def table_exists?(name) name = name.to_s schema, table = name.split('.', 2) unless table # A table was provided without a schema table = schema schema = nil end if name =~ /^"/ # Handle quoted table names table = name schema = nil end query(<<-SQL).first[0].to_i > 0 SELECT COUNT(*) FROM pg_tables WHERE tablename = '#{table.gsub(/(^"|"$)/,'')}' AND schemaname = #{schema ? "'#{schema}'" : "ANY (current_schemas(false))"} SQL end |
#tables(name = nil) ⇒ Object
Returns the list of all tables in the schema search path or a specified schema.
613 614 615 616 617 618 619 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 613 def tables(name = nil) query(<<-SQL, name).map { |row| row[0] } SELECT tablename FROM pg_tables WHERE schemaname = ANY (current_schemas(false)) SQL end |
#type_to_sql(type, limit = nil, precision = nil, scale = nil) ⇒ Object
Maps logical Rails types to PostgreSQL-specific data types.
876 877 878 879 880 881 882 883 884 885 886 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 876 def type_to_sql(type, limit = nil, precision = nil, scale = nil) return super unless type.to_s == 'integer' return 'integer' unless limit case limit when 1, 2; 'smallint' when 3, 4; 'integer' when 5..8; 'bigint' else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.") end end |
#unescape_bytea(value) ⇒ Object
Unescapes bytea output from a database to the binary string it represents. NOTE: This is NOT an inverse of escape_bytea! This is only to be used
on escaped binary output from database drive.
330 331 332 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 330 def unescape_bytea(value) @connection.unescape_bytea(value) if value end |
#update_sql(sql, name = nil) ⇒ Object
Executes an UPDATE query and returns the number of affected tuples.
524 525 526 |
# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 524 def update_sql(sql, name = nil) super.cmd_tuples end |