The PostgreSQL adapter works with the native C (github.com/ged/ruby-pg) driver.
Options:
-
:host
- Defaults to a Unix-domain socket in /tmp. On machines without Unix-domain sockets, the default is to connect to localhost. -
:port
- Defaults to 5432. -
:username
- Defaults to be the same as the operating system name of the user running the application. -
:password
- Password to be used if the server demands password authentication. -
:database
- Defaults to be the same as the username. -
: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. -
:variables
- An optional hash of additional parameters that will be used inSET SESSION key = val
calls on the connection. -
:insert_returning
- An optional boolean to control the use ofRETURNING
forINSERT
statements defaults to true.
Any further options are used as connection parameters to libpq. See www.postgresql.org/docs/current/static/libpq-connect.html for the list of parameters.
In addition, default connection parameters of libpq can be set per environment variables. See www.postgresql.org/docs/current/static/libpq-envars.html .
Methods
- active?
- create_enum
- create_unlogged_tables
- database_exists?
- datetime_type
- disable_extension
- disconnect!
- enable_extension
- enum_types
- extension_available?
- extension_enabled?
- extensions
- index_algorithms
- max_identifier_length
- new
- new_client
- reconnect!
- reset!
- session_auth=
- set_standard_conforming_strings
- supports_advisory_locks?
- supports_bulk_alter?
- supports_check_constraints?
- supports_comments?
- supports_common_table_expressions?
- supports_datetime_with_precision?
- supports_ddl_transactions?
- supports_deferrable_constraints?
- supports_explain?
- supports_expression_index?
- supports_extensions?
- supports_foreign_keys?
- supports_foreign_tables?
- supports_index_sort_order?
- supports_insert_conflict_target?
- supports_insert_on_conflict?
- supports_insert_on_duplicate_skip?
- supports_insert_on_duplicate_update?
- supports_insert_returning?
- supports_json?
- supports_lazy_transactions?
- supports_materialized_views?
- supports_optimizer_hints?
- supports_partial_index?
- supports_partitioned_indexes?
- supports_pgcrypto_uuid?
- supports_savepoints?
- supports_transaction_isolation?
- supports_validate_constraints?
- supports_views?
- supports_virtual_columns?
- use_insert_returning?
Included Modules
- ActiveRecord::ConnectionAdapters::PostgreSQL::Quoting
- ActiveRecord::ConnectionAdapters::PostgreSQL::SchemaStatements
- ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements
Constants
ADAPTER_NAME | = | "PostgreSQL" |
DEADLOCK_DETECTED | = | "40P01" |
DUPLICATE_DATABASE | = | "42P04" |
FOREIGN_KEY_VIOLATION | = | "23503" |
LOCK_NOT_AVAILABLE | = | "55P03" |
NATIVE_DATABASE_TYPES | = | { primary_key: "bigserial primary key", string: { name: "character varying" }, text: { name: "text" }, integer: { name: "integer", limit: 4 }, bigint: { name: "bigint" }, float: { name: "float" }, decimal: { name: "decimal" }, datetime: {}, # set dynamically based on datetime_type timestamp: { name: "timestamp" }, timestamptz: { name: "timestamptz" }, time: { name: "time" }, date: { name: "date" }, daterange: { name: "daterange" }, numrange: { name: "numrange" }, tsrange: { name: "tsrange" }, tstzrange: { name: "tstzrange" }, int4range: { name: "int4range" }, int8range: { name: "int8range" }, binary: { name: "bytea" }, boolean: { name: "boolean" }, xml: { name: "xml" }, tsvector: { name: "tsvector" }, hstore: { name: "hstore" }, inet: { name: "inet" }, cidr: { name: "cidr" }, macaddr: { name: "macaddr" }, uuid: { name: "uuid" }, json: { name: "json" }, jsonb: { name: "jsonb" }, ltree: { name: "ltree" }, citext: { name: "citext" }, point: { name: "point" }, line: { name: "line" }, lseg: { name: "lseg" }, box: { name: "box" }, path: { name: "path" }, polygon: { name: "polygon" }, circle: { name: "circle" }, bit: { name: "bit" }, bit_varying: { name: "bit varying" }, money: { name: "money" }, interval: { name: "interval" }, oid: { name: "oid" }, enum: {} # special type https://www.postgresql.org/docs/current/datatype-enum.html } |
NOT_NULL_VIOLATION | = | "23502" |
NUMERIC_VALUE_OUT_OF_RANGE | = | "22003" |
QUERY_CANCELED | = | "57014" |
SERIALIZATION_FAILURE | = | "40001" |
UNIQUE_VIOLATION | = | "23505" |
VALUE_LIMIT_VIOLATION | = | "22001" |
See www.postgresql.org/docs/current/static/errcodes-appendix.html |
Class Public methods
create_unlogged_tables
PostgreSQL allows the creation of “unlogged” tables, which do not record data in the PostgreSQL Write-Ahead Log. This can make the tables faster, but significantly increases the risk of data loss if the database crashes. As a result, this should not be used in production environments. If you would like all created tables to be unlogged in the test environment you can add the following line to your test.rb file:
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.create_unlogged_tables = true
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 103
class_attribute :create_unlogged_tables, default: false
database_exists?(config)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 300
def self.database_exists?(config)
!!ActiveRecord::Base.postgresql_connection(config)
rescue ActiveRecord::NoDatabaseError
false
end
datetime_type
PostgreSQL supports multiple types for DateTimes. By default if you use `datetime` in migrations, Rails will translate this to a PostgreSQL “timestamp without time zone”. Change this in an initializer to use another NATIVE_DATABASE_TYPES
. For example, to store DateTimes as “timestamp with time zone”:
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.datetime_type = :timestamptz
Or if you are adding a custom type:
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::NATIVE_DATABASE_TYPES[:my_custom_type] = { name: "my_custom_type_name" }
ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.datetime_type = :my_custom_type
If you're using :ruby as your config.active_record.schema_format and you change this setting, you should immediately run bin/rails db:migrate to update the types in your schema.rb.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 121
class_attribute :datetime_type, default: :timestamp
new(connection, logger, connection_parameters, config)
Initializes and connects a PostgreSQL adapter.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 281
def initialize(connection, logger, connection_parameters, config)
super(connection, logger, config)
@connection_parameters = connection_parameters || {}
# @local_tz is initialized as nil to avoid warnings when connect tries to use it
@local_tz = nil
@max_identifier_length = nil
configure_connection
add_pg_encoders
add_pg_decoders
@type_map = Type::HashLookupTypeMap.new
initialize_type_map
@local_tz = execute("SHOW TIME ZONE", "SCHEMA").first["TimeZone"]
@use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end
new_client(conn_params)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 77
def new_client(conn_params)
PG.connect(**conn_params)
rescue ::PG::Error => error
if conn_params && conn_params[:dbname] && error.message.include?(conn_params[:dbname])
raise ActiveRecord::NoDatabaseError.db_error(conn_params[:dbname])
elsif conn_params && conn_params[:user] && error.message.include?(conn_params[:user])
raise ActiveRecord::DatabaseConnectionError.username_error(conn_params[:user])
elsif conn_params && conn_params[:hostname] && error.message.include?(conn_params[:hostname])
raise ActiveRecord::DatabaseConnectionError.hostname_error(conn_params[:hostname])
else
raise ActiveRecord::ConnectionNotEstablished, error.message
end
end
Instance Public methods
active?()
Is this connection alive and ready for queries?
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 307
def active?
@lock.synchronize do
@connection.query ";"
end
true
rescue PG::Error
false
end
create_enum(name, values)
Given a name and an array of values, creates an enum type.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 472
def create_enum(name, values)
sql_values = values.map { |s| "'#{s}'" }.join(", ")
query = <<~SQL
DO $$
BEGIN
IF NOT EXISTS (
SELECT 1 FROM pg_type t
WHERE t.typname = '#{name}'
) THEN
CREATE TYPE \"#{name}\" AS ENUM (#{sql_values});
END IF;
END
$$;
SQL
exec_query(query)
end
disable_extension(name)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 439
def disable_extension(name)
exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
reload_type_map
}
end
disconnect!()
Disconnects from the database if already connected. Otherwise, this method does nothing.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 347
def disconnect!
@lock.synchronize do
super
@connection.close rescue nil
end
end
enable_extension(name)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 433
def enable_extension(name)
exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
reload_type_map
}
end
enum_types()
Returns a list of defined enum types, and their values.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 458
def enum_types
query = <<~SQL
SELECT
type.typname AS name,
string_agg(enum.enumlabel, ',' ORDER BY enum.enumsortorder) AS value
FROM pg_enum AS enum
JOIN pg_type AS type
ON (type.oid = enum.enumtypid)
GROUP BY type.typname;
SQL
exec_query(query, "SCHEMA").cast_values
end
extension_available?(name)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 445
def extension_available?(name)
query_value("SELECT true FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end
extension_enabled?(name)
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 449
def extension_enabled?(name)
query_value("SELECT installed_version IS NOT NULL FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end
extensions()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 453
def extensions
exec_query("SELECT extname FROM pg_extension", "SCHEMA").cast_values
end
index_algorithms()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 252
def index_algorithms
{ concurrently: "CONCURRENTLY" }
end
max_identifier_length()
Returns the configured supported identifier length supported by PostgreSQL
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 490
def max_identifier_length
@max_identifier_length ||= query_value("SHOW max_identifier_length", "SCHEMA").to_i
end
reconnect!()
Close then reopen the connection.
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 322
def reconnect!
@lock.synchronize do
super
@connection.reset
configure_connection
reload_type_map
rescue PG::ConnectionBad
connect
end
end
reset!()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 333
def reset!
@lock.synchronize do
clear_cache!
reset_transaction
unless @connection.transaction_status == ::PG::PQTRANS_IDLE
@connection.query "ROLLBACK"
end
@connection.query "DISCARD ALL"
configure_connection
end
end
session_auth=(user)
Set the authorized user for this session
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 495
def session_auth=(user)
clear_cache!
execute("SET SESSION AUTHORIZATION #{user}")
end
set_standard_conforming_strings()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 372
def set_standard_conforming_strings
execute("SET standard_conforming_strings = on", "SCHEMA")
end
supports_advisory_locks?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 380
def supports_advisory_locks?
true
end
supports_bulk_alter?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 177
def supports_bulk_alter?
true
end
supports_check_constraints?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 205
def supports_check_constraints?
true
end
supports_comments?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 229
def supports_comments?
true
end
supports_common_table_expressions?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 411
def supports_common_table_expressions?
true
end
supports_datetime_with_precision?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 221
def supports_datetime_with_precision?
true
end
supports_ddl_transactions?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 376
def supports_ddl_transactions?
true
end
supports_deferrable_constraints?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 213
def supports_deferrable_constraints?
true
end
supports_explain?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 384
def supports_explain?
true
end
supports_expression_index?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 193
def supports_expression_index?
true
end
supports_extensions?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 388
def supports_extensions?
true
end
supports_foreign_keys?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 201
def supports_foreign_keys?
true
end
supports_foreign_tables?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 396
def supports_foreign_tables?
true
end
supports_index_sort_order?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 181
def supports_index_sort_order?
true
end
supports_insert_on_conflict?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 241
def supports_insert_on_conflict?
database_version >= 90500 # >= 9.5
end
supports_insert_returning?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 237
def supports_insert_returning?
true
end
supports_json?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 225
def supports_json?
true
end
supports_lazy_transactions?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 415
def supports_lazy_transactions?
true
end
supports_materialized_views?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 392
def supports_materialized_views?
true
end
supports_optimizer_hints?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 404
def supports_optimizer_hints?
unless defined?(@has_pg_hint_plan)
@has_pg_hint_plan = extension_available?("pg_hint_plan")
end
@has_pg_hint_plan
end
supports_partial_index?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 189
def supports_partial_index?
true
end
supports_partitioned_indexes?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 185
def supports_partitioned_indexes?
database_version >= 110_000 # >= 11.0
end
supports_pgcrypto_uuid?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 400
def supports_pgcrypto_uuid?
database_version >= 90400 # >= 9.4
end
supports_savepoints?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 233
def supports_savepoints?
true
end
supports_transaction_isolation?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 197
def supports_transaction_isolation?
true
end
supports_validate_constraints?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 209
def supports_validate_constraints?
true
end
supports_views?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 217
def supports_views?
true
end
supports_virtual_columns?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 248
def supports_virtual_columns?
database_version >= 120_000 # >= 12.0
end
use_insert_returning?()
Source:
# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 500
def use_insert_returning?
@use_insert_returning
end