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 C-based (www.postgresql.jp/interfaces/ruby/) and the Ruby-base (available both as gem and from rubyforge.org/frs/?group_id=234&release_id=1145) 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 using in a SET client_encoding TO <encoding> call on connection. -
:min_messages
– An optional client min messages that is using in a SET client_min_messages TO <min_messages> call on connection.
Instance Method Summary collapse
-
#active? ⇒ Boolean
Is this connection alive and ready for queries?.
- #adapter_name ⇒ Object
- #add_column(table_name, column_name, type, options = {}) ⇒ Object
-
#begin_db_transaction ⇒ Object
:nodoc:.
-
#change_column(table_name, column_name, type, options = {}) ⇒ Object
:nodoc:.
-
#change_column_default(table_name, column_name, default) ⇒ Object
:nodoc:.
-
#columns(table_name, name = nil) ⇒ Object
:nodoc:.
-
#commit_db_transaction ⇒ Object
:nodoc:.
- #default_sequence_name(table_name, pk = nil) ⇒ Object
- #disconnect! ⇒ Object
-
#execute(sql, name = nil) ⇒ Object
:nodoc:.
-
#indexes(table_name, name = nil) ⇒ Object
:nodoc:.
-
#initialize(connection, logger, config = {}) ⇒ PostgreSQLAdapter
constructor
A new instance of PostgreSQLAdapter.
-
#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object
:nodoc:.
- #native_database_types ⇒ Object
-
#pk_and_sequence_for(table) ⇒ Object
Find a table’s primary key and sequence.
-
#query(sql, name = nil) ⇒ Object
:nodoc:.
-
#quote(value, column = nil) ⇒ Object
QUOTING ==================================================.
- #quote_column_name(name) ⇒ Object
-
#reconnect! ⇒ Object
Close then reopen the connection.
-
#remove_index(table_name, options) ⇒ Object
:nodoc:.
-
#rename_column(table_name, column_name, new_column_name) ⇒ Object
:nodoc:.
- #rename_table(name, new_name) ⇒ Object
-
#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object
Resets sequence to the max value of the table’s pk if present.
-
#rollback_db_transaction ⇒ Object
:nodoc:.
-
#schema_search_path ⇒ Object
:nodoc:.
-
#schema_search_path=(schema_csv) ⇒ Object
Set the schema search path to a string of comma-separated schema names.
-
#select_all(sql, name = nil) ⇒ Object
DATABASE STATEMENTS ======================================.
-
#select_one(sql, name = nil) ⇒ Object
:nodoc:.
- #supports_migrations? ⇒ Boolean
- #table_alias_length ⇒ Object
-
#tables(name = nil) ⇒ Object
Return the list of all tables in the schema search path.
-
#update(sql, name = nil) ⇒ Object
(also: #delete)
:nodoc:.
Methods inherited from AbstractAdapter
#prefetch_primary_key?, #raw_connection, #reset_runtime, #supports_count_distinct?, #verify!
Methods included from Quoting
#quote_string, #quoted_date, #quoted_false, #quoted_true
Methods included from DatabaseStatements
#add_limit!, #add_limit_offset!, #reset_sequence!, #select_value, #select_values, #transaction
Methods included from SchemaStatements
#add_column_options!, #add_index, #create_table, #drop_table, #dump_schema_information, #index_name, #initialize_schema_information, #remove_column, #structure_dump, #table_alias_for, #type_to_sql
Constructor Details
#initialize(connection, logger, config = {}) ⇒ PostgreSQLAdapter
Returns a new instance of PostgreSQLAdapter.
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 54 def initialize(connection, logger, config = {}) super(connection, logger) @config = config configure_connection end |
Instance Method Details
#active? ⇒ Boolean
Is this connection alive and ready for queries?
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 61 def active? if @connection.respond_to?(:status) @connection.status == PGconn::CONNECTION_OK else @connection.query 'SELECT 1' true end # postgres-pr raises a NoMethodError when querying if no conn is available rescue PGError, NoMethodError false end |
#adapter_name ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 50 def adapter_name 'PostgreSQL' end |
#add_column(table_name, column_name, type, options = {}) ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 309 def add_column(table_name, column_name, type, = {}) execute("ALTER TABLE #{table_name} ADD #{column_name} #{type_to_sql(type, [:limit])}") execute("ALTER TABLE #{table_name} ALTER #{column_name} SET NOT NULL") if [:null] == false change_column_default(table_name, column_name, [:default]) unless [:default].nil? end |
#begin_db_transaction ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 158 def begin_db_transaction #:nodoc: execute "BEGIN" end |
#change_column(table_name, column_name, type, options = {}) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 315 def change_column(table_name, column_name, type, = {}) #:nodoc: begin execute "ALTER TABLE #{table_name} ALTER #{column_name} TYPE #{type_to_sql(type, [:limit])}" rescue ActiveRecord::StatementInvalid # This is PG7, so we use a more arcane way of doing it. begin_db_transaction add_column(table_name, "#{column_name}_ar_tmp", type, ) execute "UPDATE #{table_name} SET #{column_name}_ar_tmp = CAST(#{column_name} AS #{type_to_sql(type, [:limit])})" remove_column(table_name, column_name) rename_column(table_name, "#{column_name}_ar_tmp", column_name) commit_db_transaction end change_column_default(table_name, column_name, [:default]) unless [:default].nil? end |
#change_column_default(table_name, column_name, default) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 330 def change_column_default(table_name, column_name, default) #:nodoc: execute "ALTER TABLE #{table_name} ALTER COLUMN #{column_name} SET DEFAULT '#{default}'" end |
#columns(table_name, name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 216 def columns(table_name, name = nil) #:nodoc: column_definitions(table_name).collect do |name, type, default, notnull| Column.new(name, default_value(default), translate_field_type(type), notnull == "f") end end |
#commit_db_transaction ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 162 def commit_db_transaction #:nodoc: execute "COMMIT" end |
#default_sequence_name(table_name, pk = nil) ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 237 def default_sequence_name(table_name, pk = nil) default_pk, default_seq = pk_and_sequence_for(table_name) default_seq || "#{table_name}_#{pk || default_pk || 'id'}_seq" end |
#disconnect! ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 82 def disconnect! # Both postgres and postgres-pr respond to :close @connection.close rescue nil end |
#execute(sql, name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 147 def execute(sql, name = nil) #:nodoc: log(sql, name) { @connection.exec(sql) } end |
#indexes(table_name, name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 183 def indexes(table_name, name = nil) #:nodoc: result = query(<<-SQL, name) SELECT i.relname, d.indisunique, a.attname FROM pg_class t, pg_class i, pg_index d, pg_attribute a WHERE i.relkind = 'i' AND d.indexrelid = i.oid AND d.indisprimary = 'f' AND t.oid = d.indrelid AND t.relname = '#{table_name}' AND a.attrelid = t.oid AND ( d.indkey[0]=a.attnum OR d.indkey[1]=a.attnum OR d.indkey[2]=a.attnum OR d.indkey[3]=a.attnum OR d.indkey[4]=a.attnum OR d.indkey[5]=a.attnum OR d.indkey[6]=a.attnum OR d.indkey[7]=a.attnum OR d.indkey[8]=a.attnum OR d.indkey[9]=a.attnum ) ORDER BY i.relname SQL current_index = nil indexes = [] result.each do |row| if current_index != row[0] indexes << IndexDefinition.new(table_name, row[0], row[1] == "t", []) current_index = row[0] end indexes.last.columns << row[2] end indexes end |
#insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 137 def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc: execute(sql, name) table = sql.split(" ", 4)[2] id_value || last_insert_id(table, sequence_name || default_sequence_name(table, pk)) end |
#native_database_types ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 87 def native_database_types { :primary_key => "serial primary key", :string => { :name => "character varying", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "integer" }, :float => { :name => "float" }, :datetime => { :name => "timestamp" }, :timestamp => { :name => "timestamp" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "bytea" }, :boolean => { :name => "boolean" } } end |
#pk_and_sequence_for(table) ⇒ Object
Find a table’s primary key and sequence.
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 261 def pk_and_sequence_for(table) # First try looking for a sequence with a dependency on the # given table's primary key. result = execute(<<-end_sql, 'PK and serial sequence')[0] SELECT attr.attname, name.nspname, 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.relnamespace = name.oid 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 = '#{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). # TODO: assumes sequence is in same schema as table. result = execute(<<-end_sql, 'PK and custom sequence')[0] SELECT attr.attname, name.nspname, split_part(def.adsrc, '\\\'', 2) FROM pg_class t JOIN pg_namespace name ON (t.relnamespace = name.oid) 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 = '#{table}'::regclass AND cons.contype = 'p' AND def.adsrc ~* 'nextval' end_sql end # check for existence of . in sequence name as in public.foo_sequence. if it does not exist, join the current namespace result.last['.'] ? [result.first, result.last] : [result.first, "#{result[1]}.#{result[2]}"] rescue nil end |
#query(sql, name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 143 def query(sql, name = nil) #:nodoc: log(sql, name) { @connection.query(sql) } end |
#quote(value, column = nil) ⇒ Object
QUOTING ==================================================
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 113 def quote(value, column = nil) if value.kind_of?(String) && column && column.type == :binary "'#{escape_bytea(value)}'" else super end end |
#quote_column_name(name) ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 121 def quote_column_name(name) %("#{name}") end |
#reconnect! ⇒ Object
Close then reopen the connection.
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 74 def reconnect! # TODO: postgres-pr doesn't have PGconn#reset. if @connection.respond_to?(:reset) @connection.reset configure_connection end end |
#remove_index(table_name, options) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 338 def remove_index(table_name, ) #:nodoc: execute "DROP INDEX #{index_name(table_name, )}" end |
#rename_column(table_name, column_name, new_column_name) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 334 def rename_column(table_name, column_name, new_column_name) #:nodoc: execute "ALTER TABLE #{table_name} RENAME COLUMN #{column_name} TO #{new_column_name}" end |
#rename_table(name, new_name) ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 305 def rename_table(name, new_name) execute "ALTER TABLE #{name} RENAME TO #{new_name}" end |
#reset_pk_sequence!(table, pk = nil, sequence = nil) ⇒ Object
Resets sequence to the max value of the table’s pk if present.
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 243 def reset_pk_sequence!(table, pk = nil, sequence = nil) unless pk and sequence default_pk, default_sequence = pk_and_sequence_for(table) pk ||= default_pk sequence ||= default_sequence end if pk if sequence select_value <<-end_sql, 'Reset sequence' SELECT setval('#{sequence}', (SELECT COALESCE(MAX(#{pk})+(SELECT increment_by FROM #{sequence}), (SELECT min_value FROM #{sequence})) FROM #{table}), false) end_sql else @logger.warn "#{table} has primary key #{pk} with no default sequence" if @logger end end end |
#rollback_db_transaction ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 166 def rollback_db_transaction #:nodoc: execute "ROLLBACK" end |
#schema_search_path ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 233 def schema_search_path #:nodoc: @schema_search_path ||= query('SHOW search_path')[0][0] end |
#schema_search_path=(schema_csv) ⇒ Object
Set the schema search path to a string of comma-separated schema names. Names beginning with $ are quoted (e.g. $user => ‘$user’) See www.postgresql.org/docs/8.0/interactive/ddl-schemas.html
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 226 def schema_search_path=(schema_csv) #:nodoc: if schema_csv execute "SET search_path TO #{schema_csv}" @schema_search_path = nil end end |
#select_all(sql, name = nil) ⇒ Object
DATABASE STATEMENTS ======================================
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 128 def select_all(sql, name = nil) #:nodoc: select(sql, name) end |
#select_one(sql, name = nil) ⇒ Object
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 132 def select_one(sql, name = nil) #:nodoc: result = select(sql, name) result.first if result end |
#supports_migrations? ⇒ Boolean
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 103 def supports_migrations? true end |
#table_alias_length ⇒ Object
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 107 def table_alias_length 63 end |
#tables(name = nil) ⇒ Object
Return the list of all tables in the schema search path.
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 174 def tables(name = nil) #:nodoc: schemas = schema_search_path.split(/,/).map { |p| quote(p) }.join(',') query(<<-SQL, name).map { |row| row[0] } SELECT tablename FROM pg_tables WHERE schemaname IN (#{schemas}) SQL end |
#update(sql, name = nil) ⇒ Object Also known as: delete
:nodoc:
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# File 'lib/active_record/connection_adapters/postgresql_adapter.rb', line 151 def update(sql, name = nil) #:nodoc: execute(sql, name).cmdtuples end |