Active Record PostgreSQL 适配器

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 116
class_attribute :create_unlogged_tables, default: false

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 134
class_attribute :datetime_type, default: :timestamp

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 84
def dbconsole(config, options = {})
  pg_config = config.configuration_hash

  ENV["PGUSER"]         = pg_config[:username] if pg_config[:username]
  ENV["PGHOST"]         = pg_config[:host] if pg_config[:host]
  ENV["PGPORT"]         = pg_config[:port].to_s if pg_config[:port]
  ENV["PGPASSWORD"]     = pg_config[:password].to_s if pg_config[:password] && options[:include_password]
  ENV["PGSSLMODE"]      = pg_config[:sslmode].to_s if pg_config[:sslmode]
  ENV["PGSSLCERT"]      = pg_config[:sslcert].to_s if pg_config[:sslcert]
  ENV["PGSSLKEY"]       = pg_config[:sslkey].to_s if pg_config[:sslkey]
  ENV["PGSSLROOTCERT"]  = pg_config[:sslrootcert].to_s if pg_config[:sslrootcert]
  if pg_config[:variables]
    ENV["PGOPTIONS"] = pg_config[:variables].filter_map do |name, value|
      "-c #{name}=#{value.to_s.gsub(/[ \\]/, '\\\\\0')}" unless value == ":default" || value == :default
    end.join(" ")
  end
  find_cmd_and_exec("psql", config.database)
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 322
def initialize(...)
  super

  conn_params = @config.compact

  # Map ActiveRecords param names to PGs.
  conn_params[:user] = conn_params.delete(:username) if conn_params[:username]
  conn_params[:dbname] = conn_params.delete(:database) if conn_params[:database]

  # Forward only valid config params to PG::Connection.connect.
  valid_conn_param_keys = PG::Connection.conndefaults_hash.keys + [:requiressl]
  conn_params.slice!(*valid_conn_param_keys)

  @connection_parameters = conn_params

  @max_identifier_length = nil
  @type_map = nil
  @raw_connection = nil
  @notice_receiver_sql_warnings = []

  @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 68
def new_client(conn_params)
  PG.connect(**conn_params)
rescue ::PG::Error => error
  if conn_params && conn_params[:dbname] == "postgres"
    raise ActiveRecord::ConnectionNotEstablished, error.message
  elsif 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[:host] && error.message.include?(conn_params[:host])
    raise ActiveRecord::DatabaseConnectionError.hostname_error(conn_params[:host])
  else
    raise ActiveRecord::ConnectionNotEstablished, error.message
  end
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 346
def active?
  @lock.synchronize do
    return false unless @raw_connection
    @raw_connection.query ";"
  end
  true
rescue PG::Error
  false
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 570
def add_enum_value(type_name, value, options = {})
  before, after = options.values_at(:before, :after)
  sql = +"ALTER TYPE #{quote_table_name(type_name)} ADD VALUE '#{value}'"

  if before && after
    raise ArgumentError, "Cannot have both :before and :after at the same time"
  elsif before
    sql << " BEFORE '#{before}'"
  elsif after
    sql << " AFTER '#{after}'"
  end

  execute(sql).tap { reload_type_map }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 525
      def create_enum(name, values, **options)
        sql_values = values.map { |s| quote(s) }.join(", ")
        scope = quoted_scope(name)
        query = <<~SQL
          DO $$
          BEGIN
              IF NOT EXISTS (
                SELECT 1
                FROM pg_type t
                JOIN pg_namespace n ON t.typnamespace = n.oid
                WHERE t.typname = #{scope[:name]}
                  AND n.nspname = #{scope[:schema]}
              ) THEN
                  CREATE TYPE #{quote_table_name(name)} AS ENUM (#{sql_values});
              END IF;
          END
          $$;
        SQL
        internal_exec_query(query).tap { reload_type_map }
      end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 483
def disable_extension(name, force: false)
  internal_exec_query("DROP EXTENSION IF EXISTS \"#{name}\"#{' CASCADE' if force == :cascade}").tap {
    reload_type_map
  }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 383
def disconnect!
  @lock.synchronize do
    super
    @raw_connection&.close rescue nil
    @raw_connection = nil
  end
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 555
      def drop_enum(name, values = nil, **options)
        query = <<~SQL
          DROP TYPE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(name)};
        SQL
        internal_exec_query(query).tap { reload_type_map }
      end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 470
def enable_extension(name, **)
  schema, name = name.to_s.split(".").values_at(-2, -1)
  sql = +"CREATE EXTENSION IF NOT EXISTS \"#{name}\""
  sql << " SCHEMA #{schema}" if schema

  internal_exec_query(sql).tap { reload_type_map }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 502
      def enum_types
        query = <<~SQL
          SELECT
            type.typname AS name,
            type.OID AS oid,
            n.nspname AS schema,
            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)
          JOIN pg_namespace n ON type.typnamespace = n.oid
          WHERE n.nspname = ANY (current_schemas(false))
          GROUP BY type.OID, n.nspname, type.typname;
        SQL

        internal_exec_query(query, "SCHEMA", allow_retry: true, materialize_transactions: false).cast_values.each_with_object({}) do |row, memo|
          name, schema = row[0], row[2]
          schema = nil if schema == current_schema
          full_name = [schema, name].compact.join(".")
          memo[full_name] = row.last
        end.to_a
      end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 489
def extension_available?(name)
  query_value("SELECT true FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 493
def extension_enabled?(name)
  query_value("SELECT installed_version IS NOT NULL FROM pg_available_extensions WHERE name = #{quote(name)}", "SCHEMA")
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 497
def extensions
  internal_exec_query("SELECT extname FROM pg_extension", "SCHEMA", allow_retry: true, materialize_transactions: false).cast_values
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 289
def index_algorithms
  { concurrently: "CONCURRENTLY" }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 600
def max_identifier_length
  @max_identifier_length ||= query_value("SHOW max_identifier_length", "SCHEMA").to_i
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 563
def rename_enum(name, options = {})
  to = options.fetch(:to) { raise ArgumentError, ":to is required" }

  exec_query("ALTER TYPE #{quote_table_name(name)} RENAME TO #{to}").tap { reload_type_map }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 586
def rename_enum_value(type_name, options = {})
  unless database_version >= 10_00_00 # >= 10.0
    raise ArgumentError, "Renaming enum values is only supported in PostgreSQL 10 or later"
  end

  from = options.fetch(:from) { raise ArgumentError, ":from is required" }
  to = options.fetch(:to) { raise ArgumentError, ":to is required" }

  execute("ALTER TYPE #{quote_table_name(type_name)} RENAME VALUE '#{from}' TO '#{to}'").tap {
    reload_type_map
  }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 368
def reset!
  @lock.synchronize do
    return connect! unless @raw_connection

    unless @raw_connection.transaction_status == ::PG::PQTRANS_IDLE
      @raw_connection.query "ROLLBACK"
    end
    @raw_connection.query "DISCARD ALL"

    super
  end
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 605
def session_auth=(user)
  clear_cache!
  internal_execute("SET SESSION AUTHORIZATION #{user}", nil, materialize_transactions: true)
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 409
def set_standard_conforming_strings
  internal_execute("SET standard_conforming_strings = on")
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 417
def supports_advisory_locks?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 190
def supports_bulk_alter?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 222
def supports_check_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 254
def supports_comments?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 448
def supports_common_table_expressions?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 246
def supports_datetime_with_precision?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 413
def supports_ddl_transactions?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 238
def supports_deferrable_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 226
def supports_exclusion_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 421
def supports_explain?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 210
def supports_expression_index?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 425
def supports_extensions?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 218
def supports_foreign_keys?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 433
def supports_foreign_tables?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 206
def supports_index_include?
  database_version >= 11_00_00 # >= 11.0
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 194
def supports_index_sort_order?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 270
def supports_insert_on_conflict?
  database_version >= 9_05_00 # >= 9.5
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 266
def supports_insert_returning?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 250
def supports_json?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 452
def supports_lazy_transactions?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 429
def supports_materialized_views?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 285
def supports_nulls_not_distinct?
  database_version >= 15_00_00 # >= 15.0
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 441
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

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 202
def supports_partial_index?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 198
def supports_partitioned_indexes?
  database_version >= 11_00_00 # >= 11.0
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 437
def supports_pgcrypto_uuid?
  database_version >= 9_04_00 # >= 9.4
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 262
def supports_restart_db_transaction?
  database_version >= 12_00_00 # >= 12.0
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 258
def supports_savepoints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 214
def supports_transaction_isolation?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 230
def supports_unique_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 234
def supports_validate_constraints?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 242
def supports_views?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 277
def supports_virtual_columns?
  database_version >= 12_00_00 # >= 12.0
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 610
def use_insert_returning?
  @use_insert_returning
end