Methods

Instance Public methods

client_min_messages()

Returns the current client message level.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 237
        def client_min_messages
          query_value("SHOW client_min_messages", "SCHEMA")
        end
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client_min_messages=(level)

Set the client message level.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 242
        def client_min_messages=(level)
          execute("SET client_min_messages TO '#{level}'", "SCHEMA")
        end
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collation()

Returns the current database collation.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 189
        def collation
          query_value("SELECT datcollate FROM pg_database WHERE datname = current_database()", "SCHEMA")
        end
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create_database(name, options = {})

Create a new PostgreSQL database. Options include :owner, :template, :encoding (defaults to utf8), :collation, :ctype, :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'
📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 22
        def create_database(name, options = {})
          options = { encoding: "utf8" }.merge!(options.symbolize_keys)

          option_string = options.each_with_object(+"") do |(key, value), memo|
            memo << case key
                    when :owner
                      " OWNER = \"#{value}\""
                    when :template
                      " TEMPLATE = \"#{value}\""
                    when :encoding
                      " ENCODING = '#{value}'"
                    when :collation
                      " LC_COLLATE = '#{value}'"
                    when :ctype
                      " LC_CTYPE = '#{value}'"
                    when :tablespace
                      " TABLESPACE = \"#{value}\""
                    when :connection_limit
                      " CONNECTION LIMIT = #{value}"
                    else
                      ""
            end
          end

          execute "CREATE DATABASE #{quote_table_name(name)}#{option_string}"
        end
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create_schema(schema_name)

Creates a schema for the given schema name.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 210
        def create_schema(schema_name)
          execute "CREATE SCHEMA #{quote_schema_name(schema_name)}"
        end
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ctype()

Returns the current database ctype.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 194
        def ctype
          query_value("SELECT datctype FROM pg_database WHERE datname = current_database()", "SCHEMA")
        end
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current_database()

Returns the current database name.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 174
        def current_database
          query_value("SELECT current_database()", "SCHEMA")
        end
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current_schema()

Returns the current schema name.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 179
        def current_schema
          query_value("SELECT current_schema", "SCHEMA")
        end
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drop_schema(schema_name, **options)

Drops the schema for the given schema name.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 215
        def drop_schema(schema_name, **options)
          execute "DROP SCHEMA#{' IF EXISTS' if options[:if_exists]} #{quote_schema_name(schema_name)} CASCADE"
        end
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encoding()

Returns the current database encoding format.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 184
        def encoding
          query_value("SELECT pg_encoding_to_char(encoding) FROM pg_database WHERE datname = current_database()", "SCHEMA")
        end
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foreign_keys(table_name)

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 483
        def foreign_keys(table_name)
          scope = quoted_scope(table_name)
          fk_info = exec_query(<<~SQL, "SCHEMA")
            SELECT t2.oid::regclass::text AS to_table, a1.attname AS column, a2.attname AS primary_key, c.conname AS name, c.confupdtype AS on_update, c.confdeltype AS on_delete, c.convalidated AS valid
            FROM pg_constraint c
            JOIN pg_class t1 ON c.conrelid = t1.oid
            JOIN pg_class t2 ON c.confrelid = t2.oid
            JOIN pg_attribute a1 ON a1.attnum = c.conkey[1] AND a1.attrelid = t1.oid
            JOIN pg_attribute a2 ON a2.attnum = c.confkey[1] AND a2.attrelid = t2.oid
            JOIN pg_namespace t3 ON c.connamespace = t3.oid
            WHERE c.contype = 'f'
              AND t1.relname = #{scope[:name]}
              AND t3.nspname = #{scope[:schema]}
            ORDER BY c.conname
          SQL

          fk_info.map do |row|
            options = {
              column: row["column"],
              name: row["name"],
              primary_key: row["primary_key"]
            }

            options[:on_delete] = extract_foreign_key_action(row["on_delete"])
            options[:on_update] = extract_foreign_key_action(row["on_update"])
            options[:validate] = row["valid"]

            ForeignKeyDefinition.new(table_name, row["to_table"], options)
          end
        end
🔎 See on GitHub

foreign_table_exists?(table_name)

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 518
        def foreign_table_exists?(table_name)
          query_values(data_source_sql(table_name, type: "FOREIGN TABLE"), "SCHEMA").any? if table_name.present?
        end
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foreign_tables()

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 514
        def foreign_tables
          query_values(data_source_sql(type: "FOREIGN TABLE"), "SCHEMA")
        end
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index_name_exists?(table_name, index_name)

Verifies existence of an index with a given name.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 68
        def index_name_exists?(table_name, index_name)
          table = quoted_scope(table_name)
          index = quoted_scope(index_name)

          query_value(<<~SQL, "SCHEMA").to_i > 0
            SELECT COUNT(*)
            FROM pg_class t
            INNER JOIN pg_index d ON t.oid = d.indrelid
            INNER JOIN pg_class i ON d.indexrelid = i.oid
            LEFT JOIN pg_namespace n ON n.oid = i.relnamespace
            WHERE i.relkind IN ('i', 'I')
              AND i.relname = #{index[:name]}
              AND t.relname = #{table[:name]}
              AND n.nspname = #{index[:schema]}
          SQL
        end
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rename_index(table_name, old_name, new_name)

Renames an index of a table. Raises error if length of new index name is greater than allowed limit.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 477
        def rename_index(table_name, old_name, new_name)
          validate_index_length!(table_name, new_name)

          execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}"
        end
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rename_table(table_name, new_name)

Renames a table. Also renames a table's primary key sequence if the sequence name exists and matches the Active Record default.

Example:

rename_table('octopuses', 'octopi')
📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 378
        def rename_table(table_name, new_name)
          clear_cache!
          schema_cache.clear_data_source_cache!(table_name.to_s)
          schema_cache.clear_data_source_cache!(new_name.to_s)
          execute "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
          pk, seq = pk_and_sequence_for(new_name)
          if pk
            idx = "#{table_name}_pkey"
            new_idx = "#{new_name}_pkey"
            execute "ALTER INDEX #{quote_table_name(idx)} RENAME TO #{quote_table_name(new_idx)}"
            if seq && seq.identifier == "#{table_name}_#{pk}_seq"
              new_seq = "#{new_name}_#{pk}_seq"
              execute "ALTER TABLE #{seq.quoted} RENAME TO #{quote_table_name(new_seq)}"
            end
          end
          rename_table_indexes(table_name, new_name)
        end
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schema_exists?(name)

Returns true if schema exists.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 63
        def schema_exists?(name)
          query_value("SELECT COUNT(*) FROM pg_namespace WHERE nspname = #{quote(name)}", "SCHEMA").to_i > 0
        end
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schema_names()

Returns an array of schema names.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 199
        def schema_names
          query_values(<<~SQL, "SCHEMA")
            SELECT nspname
              FROM pg_namespace
             WHERE nspname !~ '^pg_.*'
               AND nspname NOT IN ('information_schema')
             ORDER by nspname;
          SQL
        end
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schema_search_path()

Returns the active schema search path.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 232
        def schema_search_path
          @schema_search_path ||= query_value("SHOW search_path", "SCHEMA")
        end
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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.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 224
        def schema_search_path=(schema_csv)
          if schema_csv
            execute("SET search_path TO #{schema_csv}", "SCHEMA")
            @schema_search_path = schema_csv
          end
        end
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serial_sequence(table, column)

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 255
        def serial_sequence(table, column)
          query_value("SELECT pg_get_serial_sequence(#{quote(table)}, #{quote(column)})", "SCHEMA")
        end
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validate_check_constraint(table_name, **options)

Validates the given check constraint.

validate_check_constraint :products, name: "price_check"

The options hash accepts the same keys as add_check_constraint[rdoc-ref:ConnectionAdapters::SchemaStatements#add_check_constraint].

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 637
        def validate_check_constraint(table_name, **options)
          chk_name_to_validate = check_constraint_for!(table_name, **options).name

          validate_constraint table_name, chk_name_to_validate
        end
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validate_constraint(table_name, constraint_name)

Validates the given constraint.

Validates the constraint named constraint_name on accounts.

validate_constraint :accounts, :constraint_name
📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 604
        def validate_constraint(table_name, constraint_name)
          at = create_alter_table table_name
          at.validate_constraint constraint_name

          execute schema_creation.accept(at)
        end
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validate_foreign_key(from_table, to_table = nil, **options)

Validates the given foreign key.

Validates the foreign key on accounts.branch_id.

validate_foreign_key :accounts, :branches

Validates the foreign key on accounts.owner_id.

validate_foreign_key :accounts, column: :owner_id

Validates the foreign key named special_fk_name on the accounts table.

validate_foreign_key :accounts, name: :special_fk_name

The options hash accepts the same keys as SchemaStatements#add_foreign_key.

📝 Source code
# File activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb, line 626
        def validate_foreign_key(from_table, to_table = nil, **options)
          fk_name_to_validate = foreign_key_for!(from_table, to_table: to_table, **options).name

          validate_constraint from_table, fk_name_to_validate
        end
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