+++ /dev/null
-require 'active_record/connection_adapters/abstract_adapter'
-
-begin
- require_library_or_gem 'pg'
-rescue LoadError => e
- begin
- require_library_or_gem 'postgres'
- class PGresult
- alias_method :nfields, :num_fields unless self.method_defined?(:nfields)
- alias_method :ntuples, :num_tuples unless self.method_defined?(:ntuples)
- alias_method :ftype, :type unless self.method_defined?(:ftype)
- alias_method :cmd_tuples, :cmdtuples unless self.method_defined?(:cmd_tuples)
- end
- rescue LoadError
- raise e
- end
-end
-
-module ActiveRecord
- class Base
- # Establishes a connection to the database that's used by all Active Record objects
- def self.postgresql_connection(config) # :nodoc:
- config = config.symbolize_keys
- host = config[:host]
- port = config[:port] || 5432
- username = config[:username].to_s if config[:username]
- password = config[:password].to_s if config[:password]
-
- if config.has_key?(:database)
- database = config[:database]
- else
- raise ArgumentError, "No database specified. Missing argument: database."
- end
-
- # The postgres drivers don't allow the creation of an unconnected PGconn object,
- # so just pass a nil connection object for the time being.
- ConnectionAdapters::PostgreSQLAdapter.new(nil, logger, [host, port, nil, nil, database, username, password], config)
- end
- end
-
- module ConnectionAdapters
- # PostgreSQL-specific extensions to column definitions in a table.
- class PostgreSQLColumn < Column #:nodoc:
- # Instantiates a new PostgreSQL column definition in a table.
- def initialize(name, default, sql_type = nil, null = true)
- super(name, self.class.extract_value_from_default(default), sql_type, null)
- end
-
- private
- def extract_limit(sql_type)
- case sql_type
- when /^bigint/i; 8
- when /^smallint/i; 2
- else super
- end
- end
-
- # Extracts the scale from PostgreSQL-specific data types.
- def extract_scale(sql_type)
- # Money type has a fixed scale of 2.
- sql_type =~ /^money/ ? 2 : super
- end
-
- # Extracts the precision from PostgreSQL-specific data types.
- def extract_precision(sql_type)
- # Actual code is defined dynamically in PostgreSQLAdapter.connect
- # depending on the server specifics
- super
- end
-
- # Maps PostgreSQL-specific data types to logical Rails types.
- def simplified_type(field_type)
- case field_type
- # Numeric and monetary types
- when /^(?:real|double precision)$/
- :float
- # Monetary types
- when /^money$/
- :decimal
- # Character types
- when /^(?:character varying|bpchar)(?:\(\d+\))?$/
- :string
- # Binary data types
- when /^bytea$/
- :binary
- # Date/time types
- when /^timestamp with(?:out)? time zone$/
- :datetime
- when /^interval$/
- :string
- # Geometric types
- when /^(?:point|line|lseg|box|"?path"?|polygon|circle)$/
- :string
- # Network address types
- when /^(?:cidr|inet|macaddr)$/
- :string
- # Bit strings
- when /^bit(?: varying)?(?:\(\d+\))?$/
- :string
- # XML type
- when /^xml$/
- :string
- # Arrays
- when /^\D+\[\]$/
- :string
- # Object identifier types
- when /^oid$/
- :integer
- # Pass through all types that are not specific to PostgreSQL.
- else
- super
- end
- end
-
- # Extracts the value from a PostgreSQL column default definition.
- def self.extract_value_from_default(default)
- case default
- # Numeric types
- when /\A\(?(-?\d+(\.\d*)?\)?)\z/
- $1
- # Character types
- when /\A'(.*)'::(?:character varying|bpchar|text)\z/m
- $1
- # Character types (8.1 formatting)
- when /\AE'(.*)'::(?:character varying|bpchar|text)\z/m
- $1.gsub(/\\(\d\d\d)/) { $1.oct.chr }
- # Binary data types
- when /\A'(.*)'::bytea\z/m
- $1
- # Date/time types
- when /\A'(.+)'::(?:time(?:stamp)? with(?:out)? time zone|date)\z/
- $1
- when /\A'(.*)'::interval\z/
- $1
- # Boolean type
- when 'true'
- true
- when 'false'
- false
- # Geometric types
- when /\A'(.*)'::(?:point|line|lseg|box|"?path"?|polygon|circle)\z/
- $1
- # Network address types
- when /\A'(.*)'::(?:cidr|inet|macaddr)\z/
- $1
- # Bit string types
- when /\AB'(.*)'::"?bit(?: varying)?"?\z/
- $1
- # XML type
- when /\A'(.*)'::xml\z/m
- $1
- # Arrays
- when /\A'(.*)'::"?\D+"?\[\]\z/
- $1
- # Object identifier types
- when /\A-?\d+\z/
- $1
- else
- # Anything else is blank, some user type, or some function
- # and we can't know the value of that, so return nil.
- nil
- end
- end
- end
- end
-
- module ConnectionAdapters
- # The PostgreSQL adapter works both with the native C (http://ruby.scripting.ca/postgres/) and the pure
- # Ruby (available both as gem and from http://rubyforge.org/frs/?group_id=234&release_id=1944) drivers.
- #
- # Options:
- #
- # * <tt>:host</tt> - Defaults to "localhost".
- # * <tt>:port</tt> - Defaults to 5432.
- # * <tt>:username</tt> - Defaults to nothing.
- # * <tt>:password</tt> - Defaults to nothing.
- # * <tt>:database</tt> - The name of the database. No default, must be provided.
- # * <tt>:schema_search_path</tt> - An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the <tt>:schema_order</tt> option.
- # * <tt>:encoding</tt> - An optional client encoding that is used in a <tt>SET client_encoding TO <encoding></tt> call on the connection.
- # * <tt>:min_messages</tt> - An optional client min messages that is used in a <tt>SET client_min_messages TO <min_messages></tt> call on the connection.
- # * <tt>:allow_concurrency</tt> - If true, use async query methods so Ruby threads don't deadlock; otherwise, use blocking query methods.
- class PostgreSQLAdapter < AbstractAdapter
- 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" }
- }
-
- # Returns 'PostgreSQL' as adapter name for identification purposes.
- def adapter_name
- ADAPTER_NAME
- end
-
- # Initializes and connects a PostgreSQL adapter.
- def initialize(connection, logger, connection_parameters, config)
- super(connection, logger)
- @connection_parameters, @config = connection_parameters, config
-
- connect
- end
-
- # Is this connection alive and ready for queries?
- def active?
- if @connection.respond_to?(:status)
- @connection.status == PGconn::CONNECTION_OK
- else
- # We're asking the driver, not ActiveRecord, 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
-
- # Close then reopen the connection.
- def reconnect!
- if @connection.respond_to?(:reset)
- @connection.reset
- configure_connection
- else
- disconnect!
- connect
- end
- end
-
- # Close the connection.
- def disconnect!
- @connection.close rescue nil
- end
-
- def native_database_types #:nodoc:
- NATIVE_DATABASE_TYPES
- end
-
- # Does PostgreSQL support migrations?
- def supports_migrations?
- true
- end
-
- # Does PostgreSQL support standard conforming strings?
- def supports_standard_conforming_strings?
- # Temporarily set the client message level above error to prevent unintentional
- # error messages in the logs when working on a PostgreSQL database server that
- # does not support standard conforming strings.
- client_min_messages_old = client_min_messages
- self.client_min_messages = 'panic'
-
- # postgres-pr does not raise an exception when client_min_messages is set higher
- # than error and "SHOW standard_conforming_strings" fails, but returns an empty
- # PGresult instead.
- has_support = query('SHOW standard_conforming_strings')[0][0] rescue false
- self.client_min_messages = client_min_messages_old
- has_support
- end
-
- def supports_insert_with_returning?
- postgresql_version >= 80200
- end
-
- def supports_ddl_transactions?
- true
- end
-
- def supports_savepoints?
- true
- end
-
- # Returns the configured supported identifier length supported by PostgreSQL,
- # or report the default of 63 on PostgreSQL 7.x.
- def table_alias_length
- @table_alias_length ||= (postgresql_version >= 80000 ? query('SHOW max_identifier_length')[0][0].to_i : 63)
- end
-
- # QUOTING ==================================================
-
- # Escapes binary strings for bytea input to the database.
- def escape_bytea(value)
- if PGconn.respond_to?(:escape_bytea)
- self.class.instance_eval do
- define_method(:escape_bytea) do |value|
- PGconn.escape_bytea(value) if value
- end
- end
- else
- self.class.instance_eval do
- define_method(:escape_bytea) do |value|
- if value
- result = ''
- value.each_byte { |c| result << sprintf('\\\\%03o', c) }
- result
- end
- end
- end
- end
- escape_bytea(value)
- end
-
- # 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.
- def unescape_bytea(value)
- # In each case, check if the value actually is escaped PostgreSQL bytea output
- # or an unescaped Active Record attribute that was just written.
- if PGconn.respond_to?(:unescape_bytea)
- self.class.instance_eval do
- define_method(:unescape_bytea) do |value|
- if value =~ /\\\d{3}/
- PGconn.unescape_bytea(value)
- else
- value
- end
- end
- end
- else
- self.class.instance_eval do
- define_method(:unescape_bytea) do |value|
- if value =~ /\\\d{3}/
- result = ''
- i, max = 0, value.size
- while i < max
- char = value[i]
- if char == ?\\
- if value[i+1] == ?\\
- char = ?\\
- i += 1
- else
- char = value[i+1..i+3].oct
- i += 3
- end
- end
- result << char
- i += 1
- end
- result
- else
- value
- end
- end
- end
- end
- unescape_bytea(value)
- end
-
- # Quotes PostgreSQL-specific data types for SQL input.
- def quote(value, column = nil) #:nodoc:
- if value.kind_of?(String) && column && column.type == :binary
- "#{quoted_string_prefix}'#{escape_bytea(value)}'"
- elsif value.kind_of?(String) && column && column.sql_type =~ /^xml$/
- "xml '#{quote_string(value)}'"
- elsif value.kind_of?(Numeric) && column && column.sql_type =~ /^money$/
- # Not truly string input, so doesn't require (or allow) escape string syntax.
- "'#{value.to_s}'"
- elsif value.kind_of?(String) && column && column.sql_type =~ /^bit/
- case value
- when /^[01]*$/
- "B'#{value}'" # Bit-string notation
- when /^[0-9A-F]*$/i
- "X'#{value}'" # Hexadecimal notation
- end
- else
- super
- end
- end
-
- # Quotes strings for use in SQL input in the postgres driver for better performance.
- def quote_string(s) #:nodoc:
- if PGconn.respond_to?(:escape)
- self.class.instance_eval do
- define_method(:quote_string) do |s|
- PGconn.escape(s)
- end
- end
- else
- # There are some incorrectly compiled postgres drivers out there
- # that don't define PGconn.escape.
- self.class.instance_eval do
- remove_method(:quote_string)
- end
- end
- quote_string(s)
- end
-
- # Quotes column names for use in SQL queries.
- def quote_column_name(name) #:nodoc:
- %("#{name}")
- end
-
- # Quote date/time values for use in SQL input. Includes microseconds
- # if the value is a Time responding to usec.
- def quoted_date(value) #:nodoc:
- if value.acts_like?(:time) && value.respond_to?(:usec)
- "#{super}.#{sprintf("%06d", value.usec)}"
- else
- super
- end
- end
-
- # REFERENTIAL INTEGRITY ====================================
-
- def supports_disable_referential_integrity?() #:nodoc:
- version = query("SHOW server_version")[0][0].split('.')
- (version[0].to_i >= 8 && version[1].to_i >= 1) ? true : false
- rescue
- return false
- end
-
- def disable_referential_integrity(&block) #: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
-
- # DATABASE STATEMENTS ======================================
-
- # Executes a SELECT query and returns an array of rows. Each row is an
- # array of field values.
- def select_rows(sql, name = nil)
- select_raw(sql, name).last
- end
-
- # Executes an INSERT query and returns the new record's ID
- 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
-
- # create a 2D array representing the result set
- def result_as_array(res) #:nodoc:
- # check if we have any binary column and if they need escaping
- unescape_col = []
- for j in 0...res.nfields do
- # unescape string passed BYTEA field (OID == 17)
- unescape_col << ( res.ftype(j)==17 )
- end
-
- ary = []
- for i in 0...res.ntuples do
- ary << []
- for j in 0...res.nfields do
- data = res.getvalue(i,j)
- data = unescape_bytea(data) if unescape_col[j] and data.is_a?(String)
- ary[i] << data
- end
- end
- return ary
- end
-
-
- # Queries the database and returns the results in an Array-like object
- 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
-
- # Executes an SQL statement, returning a PGresult object on success
- # or raising a PGError exception otherwise.
- def execute(sql, name = nil)
- log(sql, name) do
- if @async
- @connection.async_exec(sql)
- else
- @connection.exec(sql)
- end
- end
- end
-
- # Executes an UPDATE query and returns the number of affected tuples.
- def update_sql(sql, name = nil)
- super.cmd_tuples
- end
-
- # Begins a transaction.
- def begin_db_transaction
- execute "BEGIN"
- end
-
- # Commits a transaction.
- def commit_db_transaction
- execute "COMMIT"
- end
-
- # Aborts a transaction.
- def rollback_db_transaction
- execute "ROLLBACK"
- end
-
- if defined?(PGconn::PQTRANS_IDLE)
- # The ruby-pg driver supports inspecting the transaction status,
- # while the ruby-postgres driver does not.
- def outside_transaction?
- @connection.transaction_status == PGconn::PQTRANS_IDLE
- end
- end
-
- def create_savepoint
- execute("SAVEPOINT #{current_savepoint_name}")
- end
-
- def rollback_to_savepoint
- execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
- end
-
- def release_savepoint
- execute("RELEASE SAVEPOINT #{current_savepoint_name}")
- end
-
- # SCHEMA STATEMENTS ========================================
-
- def recreate_database(name) #:nodoc:
- drop_database(name)
- create_database(name)
- end
-
- # Create a new PostgreSQL database. Options include <tt>:owner</tt>, <tt>:template</tt>,
- # <tt>:encoding</tt>, <tt>:tablespace</tt>, and <tt>:connection_limit</tt> (note that MySQL uses
- # <tt>:charset</tt> while PostgreSQL uses <tt>:encoding</tt>).
- #
- # Example:
- # create_database config[:database], config
- # create_database 'foo_development', :encoding => 'unicode'
- def create_database(name, options = {})
- options = options.reverse_merge(:encoding => "utf8")
-
- option_string = options.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
-
- # Drops a PostgreSQL database
- #
- # Example:
- # drop_database 'matt_development'
- 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
-
-
- # Returns the list of all tables in the schema search path or a specified schema.
- def tables(name = nil)
- 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
-
- # Returns the list of all indexes for a table.
- 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, 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 i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname IN (#{schemas}) )
- 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
-
- # Returns the list of all column definitions for a table.
- 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
-
- # Returns the current database name.
- def current_database
- query('select current_database()')[0][0]
- end
-
- # Returns the current database encoding format.
- 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
-
- # 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: http://www.postgresql.org/docs/current/static/ddl-schemas.html
- #
- # This should be not be called manually but set in database.yml.
- def schema_search_path=(schema_csv)
- if schema_csv
- execute "SET search_path TO #{schema_csv}"
- @schema_search_path = schema_csv
- end
- end
-
- # Returns the active schema search path.
- def schema_search_path
- @schema_search_path ||= query('SHOW search_path')[0][0]
- end
-
- # Returns the current client message level.
- def client_min_messages
- query('SHOW client_min_messages')[0][0]
- end
-
- # Set the client message level.
- def client_min_messages=(level)
- execute("SET client_min_messages TO '#{level}'")
- end
-
- # Returns the sequence name for a table's primary key or some other specified key.
- 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
-
- # Resets the sequence of a table's primary key to the maximum value.
- 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
-
- # Returns a table's primary key and belonging sequence.
- 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 = '#{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 = '#{table}'::regclass
- AND cons.contype = 'p'
- AND def.adsrc ~* 'nextval'
- end_sql
- end
-
- # [primary_key, sequence]
- [result.first, result.last]
- rescue
- nil
- end
-
- # Renames a table.
- def rename_table(name, new_name)
- execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
- end
-
- # Adds a new column to the named table.
- # See TableDefinition#column for details of the options you can use.
- def add_column(table_name, column_name, type, options = {})
- default = options[:default]
- notnull = options[:null] == false
-
- # Add the column.
- execute("ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}")
-
- change_column_default(table_name, column_name, default) if options_include_default?(options)
- change_column_null(table_name, column_name, false, default) if notnull
- end
-
- # Changes the column of a table.
- def change_column(table_name, column_name, type, options = {})
- 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, options[:limit], options[:precision], options[: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, options)
- execute "UPDATE #{quoted_table_name} SET #{quote_column_name(tmp_column_name)} = CAST(#{quote_column_name(column_name)} AS #{type_to_sql(type, options[:limit], options[:precision], options[: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, options[:default]) if options_include_default?(options)
- change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
- end
-
- # Changes the default value of a table column.
- 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
-
- 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
-
- # Renames a column in a table.
- 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
-
- # Drops an index from a table.
- def remove_index(table_name, options = {})
- execute "DROP INDEX #{index_name(table_name, options)}"
- end
-
- # Maps logical Rails types to PostgreSQL-specific data types.
- def type_to_sql(type, limit = nil, precision = nil, scale = nil)
- return super unless type.to_s == 'integer'
-
- case limit
- when 1..2; 'smallint'
- when 3..4, nil; 'integer'
- when 5..8; 'bigint'
- else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.")
- end
- end
-
- # 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")
- 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 &: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
-
- # Returns an ORDER BY clause for the passed order option.
- #
- # PostgreSQL does not allow arbitrary ordering when using DISTINCT ON, so we work around this
- # by wrapping the +sql+ string as a sub-select and ordering in that query.
- def add_order_by_for_association_limiting!(sql, options) #:nodoc:
- return sql if options[:order].blank?
-
- order = options[:order].split(',').collect { |s| s.strip }.reject(&:blank?)
- order.map! { |s| 'DESC' if s =~ /\bdesc$/i }
- order = order.zip((0...order.size).to_a).map { |s,i| "id_list.alias_#{i} #{s}" }.join(', ')
-
- sql.replace "SELECT * FROM (#{sql}) AS id_list ORDER BY #{order}"
- end
-
- protected
- # Returns the version of the connected PostgreSQL version.
- def postgresql_version
- @postgresql_version ||=
- if @connection.respond_to?(:server_version)
- @connection.server_version
- else
- # Mimic PGconn.server_version behavior
- begin
- query('SELECT version()')[0][0] =~ /PostgreSQL (\d+)\.(\d+)\.(\d+)/
- ($1.to_i * 10000) + ($2.to_i * 100) + $3.to_i
- rescue
- 0
- end
- end
- end
-
- private
- # The internal PostgreSQL identifier of the money data type.
- MONEY_COLUMN_TYPE_OID = 790 #:nodoc:
-
- # Connects to a PostgreSQL server and sets up the adapter depending on the
- # connected server's characteristics.
- def connect
- @connection = PGconn.connect(*@connection_parameters)
- PGconn.translate_results = false if PGconn.respond_to?(:translate_results=)
-
- # Ignore async_exec and async_query when using postgres-pr.
- @async = @config[:allow_concurrency] && @connection.respond_to?(:async_exec)
-
- # Use escape string syntax if available. We cannot do this lazily when encountering
- # the first string, because that could then break any transactions in progress.
- # See: http://www.postgresql.org/docs/current/static/runtime-config-compatible.html
- # If PostgreSQL doesn't know the standard_conforming_strings parameter then it doesn't
- # support escape string syntax. Don't override the inherited quoted_string_prefix.
- if supports_standard_conforming_strings?
- self.class.instance_eval do
- define_method(:quoted_string_prefix) { 'E' }
- end
- end
-
- # Money type has a fixed precision of 10 in PostgreSQL 8.2 and below, and as of
- # PostgreSQL 8.3 it has a fixed precision of 19. PostgreSQLColumn.extract_precision
- # should know about this but can't detect it there, so deal with it here.
- money_precision = (postgresql_version >= 80300) ? 19 : 10
- PostgreSQLColumn.module_eval(<<-end_eval)
- def extract_precision(sql_type) # def extract_precision(sql_type)
- if sql_type =~ /^money$/ # if sql_type =~ /^money$/
- #{money_precision} # 19
- else # else
- super # super
- end # end
- end # end
- end_eval
-
- configure_connection
- end
-
- # Configures the encoding, verbosity, and schema search path of the connection.
- # This is called by #connect and should not be called manually.
- def configure_connection
- if @config[:encoding]
- if @connection.respond_to?(:set_client_encoding)
- @connection.set_client_encoding(@config[:encoding])
- else
- execute("SET client_encoding TO '#{@config[:encoding]}'")
- end
- end
- self.client_min_messages = @config[:min_messages] if @config[:min_messages]
- self.schema_search_path = @config[:schema_search_path] || @config[:schema_order]
- end
-
- # Returns the current ID of a table's sequence.
- def last_insert_id(table, sequence_name) #:nodoc:
- Integer(select_value("SELECT currval('#{sequence_name}')"))
- end
-
- # Executes a SELECT query and returns the results, performing any data type
- # conversions that are required to be performed here instead of in PostgreSQLColumn.
- def select(sql, name = nil)
- fields, rows = select_raw(sql, name)
- result = []
- for row in rows
- row_hash = {}
- fields.each_with_index do |f, i|
- row_hash[f] = row[i]
- end
- result << row_hash
- end
- result
- end
-
- def select_raw(sql, name = nil)
- res = execute(sql, name)
- results = result_as_array(res)
- fields = []
- rows = []
- if res.ntuples > 0
- fields = res.fields
- results.each do |row|
- hashed_row = {}
- row.each_index do |cell_index|
- # 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.
- if res.ftype(cell_index) == 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) $12.345.678,12
- case column = row[cell_index]
- when /^-?\D+[\d,]+\.\d{2}$/ # (1)
- row[cell_index] = column.gsub(/[^-\d\.]/, '')
- when /^-?\D+[\d\.]+,\d{2}$/ # (2)
- row[cell_index] = column.gsub(/[^-\d,]/, '').sub(/,/, '.')
- end
- end
-
- hashed_row[fields[cell_index]] = column
- end
- rows << row
- end
- end
- res.clear
- return fields, rows
- end
-
- # Returns the list of a table's column names, data types, and default values.
- #
- # The underlying query is roughly:
- # SELECT column.name, column.type, default.value
- # FROM column LEFT JOIN default
- # ON column.table_id = default.table_id
- # AND column.num = default.column_num
- # WHERE column.table_id = get_table_id('table_name')
- # AND column.num > 0
- # AND NOT column.is_dropped
- # ORDER BY column.num
- #
- # If the table name is not prefixed with a schema, the database will
- # take the first match from the schema search path.
- #
- # Query implementation notes:
- # - format_type includes the column size constraint, e.g. varchar(50)
- # - ::regclass is a function that gives the id for a table name
- def column_definitions(table_name) #:nodoc:
- query <<-end_sql
- SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
- FROM pg_attribute a LEFT JOIN pg_attrdef d
- ON a.attrelid = d.adrelid AND a.attnum = d.adnum
- WHERE a.attrelid = '#{table_name}'::regclass
- AND a.attnum > 0 AND NOT a.attisdropped
- ORDER BY a.attnum
- end_sql
- end
- end
- end
-end
projects / feedcatcher.git / blobdiff