- Inheritance
- < ActiveRecord::ConnectionAdapters::AbstractAdapter < Object
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 a SET client_encoding TO <encoding> call on the connection.
- :min_messages - An optional client min messages that is used in a SET 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.
Constants
| Name | Description | |
|---|---|---|
| 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" } |
Methods
Class
| Visibility | Signature |
|---|---|
| public | new (connection, logger, connection_parameters, config) |
Instance
| Visibility | Signature |
|---|---|
| public | active? () |
| public | adapter_name () |
| public | add_column (table_name, column_name, type, options = {}) |
| public | begin_db_transaction () |
| public | change_column (table_name, column_name, type, options = {}) |
| public | change_column_default (table_name, column_name, default) |
| public | change_column_null (table_name, column_name, null, default = nil) |
| public | client_min_messages () |
| public | client_min_messages= (level) |
| public | columns (table_name, name = nil) |
| public | commit_db_transaction () |
| public | create_database (name, options = {}) |
| public | create_savepoint () |
| public | current_database () |
| public | disconnect! () |
| public | encoding () |
| public | escape_bytea (value) |
| public | execute (sql, name = nil) |
| public | indexes (table_name, name = nil) |
| public | insert (sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) |
| public | outside_transaction? () |
| public | reconnect! () |
| public | release_savepoint () |
| public | remove_index (table_name, options = {}) |
| public | rename_column (table_name, column_name, new_column_name) |
| public | rename_table (name, new_name) |
| public | rollback_db_transaction () |
| public | rollback_to_savepoint () |
| public | schema_search_path () |
| public | schema_search_path= (schema_csv) |
| public | select_rows (sql, name = nil) |
| public | supports_ddl_transactions? () |
| public | supports_insert_with_returning? () |
| public | supports_migrations? () |
| public | supports_savepoints? () |
| public | supports_standard_conforming_strings? () |
| public | table_alias_length () |
| public | tables (name = nil) |
| public | type_to_sql (type, limit = nil, precision = nil, scale = nil) |
| public | unescape_bytea (value) |
| public | update_sql (sql, name = nil) |
| protected | postgresql_version () |
Class Method Detail
new(connection, logger, connection_parameters, config)
Initializes and connects a PostgreSQL adapter.
Instance Method Detail
active?()
Is this connection alive and ready for queries?
adapter_name()
Returns ‘PostgreSQL’ as adapter name for identification purposes.
add_column(table_name, column_name, type, options = {})
Adds a new column to the named table. See TableDefinition#column for details of the options you can use.
begin_db_transaction()
Begins a transaction.
change_column(table_name, column_name, type, options = {})
Changes the column of a table.
change_column_default(table_name, column_name, default)
Changes the default value of a table column.
change_column_null(table_name, column_name, null, default = nil)
client_min_messages()
Returns the current client message level.
client_min_messages=(level)
Set the client message level.
columns(table_name, name = nil)
Returns the list of all column definitions for a table.
commit_db_transaction()
Commits a transaction.
create_database(name, options = {})
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'
create_savepoint()
current_database()
Returns the current database name.
disconnect!()
Close the connection.
encoding()
Returns the current database encoding format.
escape_bytea(value)
Escapes binary strings for bytea input to the database.
execute(sql, name = nil)
Executes an SQL statement, returning a PGresult object on success or raising a PGError exception otherwise.
indexes(table_name, name = nil)
Returns the list of all indexes for a table.
insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
Executes an INSERT query and returns the new record‘s ID
outside_transaction?()
The ruby-pg driver supports inspecting the transaction status, while the ruby-postgres driver does not.
reconnect!()
Close then reopen the connection.
release_savepoint()
remove_index(table_name, options = {})
Drops an index from a table.
rename_column(table_name, column_name, new_column_name)
Renames a column in a table.
rename_table(name, new_name)
Renames a table.
rollback_db_transaction()
Aborts a transaction.
rollback_to_savepoint()
schema_search_path()
Returns the active schema search path.
schema_search_path=(schema_csv)
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.
select_rows(sql, name = nil)
Executes a SELECT query and returns an array of rows. Each row is an array of field values.
supports_ddl_transactions?()
supports_insert_with_returning?()
supports_migrations?()
Does PostgreSQL support migrations?
supports_savepoints?()
supports_standard_conforming_strings?()
Does PostgreSQL support standard conforming strings?
table_alias_length()
Returns the configured supported identifier length supported by PostgreSQL, or report the default of 63 on PostgreSQL 7.x.
tables(name = nil)
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)
Maps logical Rails types to PostgreSQL-specific data types.
unescape_bytea(value)
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.
update_sql(sql, name = nil)
Executes an UPDATE query and returns the number of affected tuples.
postgresql_version()
Returns the version of the connected PostgreSQL version.