diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/postgresql')
5 files changed, 902 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb b/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb new file mode 100644 index 0000000000..20e482dcc2 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql/cast.rb @@ -0,0 +1,80 @@ +module ActiveRecord + module ConnectionAdapters + class PostgreSQLColumn < Column + module Cast + def string_to_time(string) + return string unless String === string + + case string + when 'infinity'; 1.0 / 0.0 + when '-infinity'; -1.0 / 0.0 + else + super + end + end + + def hstore_to_string(object) + if Hash === object + object.map { |k,v| + "#{escape_hstore(k)}=>#{escape_hstore(v)}" + }.join ',' + else + object + end + end + + def string_to_hstore(string) + if string.nil? + nil + elsif String === string + Hash[string.scan(HstorePair).map { |k,v| + v = v.upcase == 'NULL' ? nil : v.gsub(/^"(.*)"$/,'\1').gsub(/\\(.)/, '\1') + k = k.gsub(/^"(.*)"$/,'\1').gsub(/\\(.)/, '\1') + [k,v] + }] + else + string + end + end + + def string_to_cidr(string) + if string.nil? + nil + elsif String === string + IPAddr.new(string) + else + string + end + end + + def cidr_to_string(object) + if IPAddr === object + "#{object.to_s}/#{object.instance_variable_get(:@mask_addr).to_s(2).count('1')}" + else + object + end + end + + private + + HstorePair = begin + quoted_string = /"[^"\\]*(?:\\.[^"\\]*)*"/ + unquoted_string = /(?:\\.|[^\s,])[^\s=,\\]*(?:\\.[^\s=,\\]*|=[^,>])*/ + /(#{quoted_string}|#{unquoted_string})\s*=>\s*(#{quoted_string}|#{unquoted_string})/ + end + + def escape_hstore(value) + if value.nil? + 'NULL' + else + if value == "" + '""' + else + '"%s"' % value.to_s.gsub(/(["\\])/, '\\\\\1') + end + end + end + end + end + end +end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb new file mode 100644 index 0000000000..eb3084e066 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb @@ -0,0 +1,234 @@ +module ActiveRecord + module ConnectionAdapters + class PostgreSQLAdapter < AbstractAdapter + module DatabaseStatements + def explain(arel, binds = []) + sql = "EXPLAIN #{to_sql(arel, binds)}" + ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds)) + end + + class ExplainPrettyPrinter # :nodoc: + # Pretty prints the result of a EXPLAIN in a way that resembles the output of the + # PostgreSQL shell: + # + # QUERY PLAN + # ------------------------------------------------------------------------------ + # Nested Loop Left Join (cost=0.00..37.24 rows=8 width=0) + # Join Filter: (posts.user_id = users.id) + # -> Index Scan using users_pkey on users (cost=0.00..8.27 rows=1 width=4) + # Index Cond: (id = 1) + # -> Seq Scan on posts (cost=0.00..28.88 rows=8 width=4) + # Filter: (posts.user_id = 1) + # (6 rows) + # + def pp(result) + header = result.columns.first + lines = result.rows.map(&:first) + + # We add 2 because there's one char of padding at both sides, note + # the extra hyphens in the example above. + width = [header, *lines].map(&:length).max + 2 + + pp = [] + + pp << header.center(width).rstrip + pp << '-' * width + + pp += lines.map {|line| " #{line}"} + + nrows = result.rows.length + rows_label = nrows == 1 ? 'row' : 'rows' + pp << "(#{nrows} #{rows_label})" + + pp.join("\n") + "\n" + end + end + + # 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(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) + unless pk + # Extract the table from the insert sql. Yuck. + table_ref = extract_table_ref_from_insert_sql(sql) + pk = primary_key(table_ref) if table_ref + end + + if pk && use_insert_returning? + select_value("#{sql} RETURNING #{quote_column_name(pk)}") + elsif pk + super + last_insert_id_value(sequence_name || default_sequence_name(table_ref, pk)) + else + super + end + end + + def create + super.insert + 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 + ftypes = Array.new(res.nfields) do |i| + [i, res.ftype(i)] + end + + rows = res.values + return rows unless ftypes.any? { |_, x| + x == BYTEA_COLUMN_TYPE_OID || x == MONEY_COLUMN_TYPE_OID + } + + typehash = ftypes.group_by { |_, type| type } + binaries = typehash[BYTEA_COLUMN_TYPE_OID] || [] + monies = typehash[MONEY_COLUMN_TYPE_OID] || [] + + rows.each do |row| + # unescape string passed BYTEA field (OID == 17) + binaries.each do |index, _| + row[index] = unescape_bytea(row[index]) + end + + # 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. + monies.each do |index, _| + data = row[index] + # 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) $12.345.678,12 + case data + when /^-?\D+[\d,]+\.\d{2}$/ # (1) + data.gsub!(/[^-\d.]/, '') + when /^-?\D+[\d.]+,\d{2}$/ # (2) + data.gsub!(/[^-\d,]/, '').sub!(/,/, '.') + end + end + end + end + + # Queries the database and returns the results in an Array-like object + def query(sql, name = nil) #:nodoc: + log(sql, name) do + result_as_array @connection.async_exec(sql) + end + end + + # Executes an SQL statement, returning a PGresult object on success + # or raising a PGError exception otherwise. + def execute(sql, name = nil) + log(sql, name) do + @connection.async_exec(sql) + end + end + + def substitute_at(column, index) + Arel::Nodes::BindParam.new "$#{index + 1}" + end + + def exec_query(sql, name = 'SQL', binds = []) + log(sql, name, binds) do + result = binds.empty? ? exec_no_cache(sql, binds) : + exec_cache(sql, binds) + + types = {} + result.fields.each_with_index do |fname, i| + ftype = result.ftype i + fmod = result.fmod i + types[fname] = OID::TYPE_MAP.fetch(ftype, fmod) { |oid, mod| + warn "unknown OID: #{fname}(#{oid}) (#{sql})" + OID::Identity.new + } + end + + ret = ActiveRecord::Result.new(result.fields, result.values, types) + result.clear + return ret + end + end + + def exec_delete(sql, name = 'SQL', binds = []) + log(sql, name, binds) do + result = binds.empty? ? exec_no_cache(sql, binds) : + exec_cache(sql, binds) + affected = result.cmd_tuples + result.clear + affected + end + end + alias :exec_update :exec_delete + + def sql_for_insert(sql, pk, id_value, sequence_name, binds) + unless pk + # Extract the table from the insert sql. Yuck. + table_ref = extract_table_ref_from_insert_sql(sql) + pk = primary_key(table_ref) if table_ref + end + + if pk && use_insert_returning? + sql = "#{sql} RETURNING #{quote_column_name(pk)}" + end + + [sql, binds] + end + + def exec_insert(sql, name, binds, pk = nil, sequence_name = nil) + val = exec_query(sql, name, binds) + if !use_insert_returning? && pk + unless sequence_name + table_ref = extract_table_ref_from_insert_sql(sql) + sequence_name = default_sequence_name(table_ref, pk) + return val unless sequence_name + end + last_insert_id_result(sequence_name) + else + val + 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 + + def outside_transaction? + @connection.transaction_status == PGconn::PQTRANS_IDLE + 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 + end + end + end +end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb new file mode 100644 index 0000000000..1ae7443cde --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb @@ -0,0 +1,120 @@ +module ActiveRecord + module ConnectionAdapters + class PostgreSQLAdapter < AbstractAdapter + module Quoting + # Escapes binary strings for bytea input to the database. + def escape_bytea(value) + PGconn.escape_bytea(value) if 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) + PGconn.unescape_bytea(value) if value + end + + # Quotes PostgreSQL-specific data types for SQL input. + def quote(value, column = nil) #:nodoc: + return super unless column + + case value + when Hash + case column.sql_type + when 'hstore' then super(PostgreSQLColumn.hstore_to_string(value), column) + else super + end + when IPAddr + case column.sql_type + when 'inet', 'cidr' then super(PostgreSQLColumn.cidr_to_string(value), column) + else super + end + when Float + if value.infinite? && column.type == :datetime + "'#{value.to_s.downcase}'" + elsif value.infinite? || value.nan? + "'#{value.to_s}'" + else + super + end + when Numeric + return super unless column.sql_type == 'money' + # Not truly string input, so doesn't require (or allow) escape string syntax. + "'#{value}'" + when String + case column.sql_type + when 'bytea' then "'#{escape_bytea(value)}'" + when 'xml' then "xml '#{quote_string(value)}'" + when /^bit/ + case value + when /^[01]*$/ then "B'#{value}'" # Bit-string notation + when /^[0-9A-F]*$/i then "X'#{value}'" # Hexadecimal notation + end + else + super + end + else + super + end + end + + def type_cast(value, column) + return super unless column + + case value + when String + return super unless 'bytea' == column.sql_type + { :value => value, :format => 1 } + when Hash + return super unless 'hstore' == column.sql_type + PostgreSQLColumn.hstore_to_string(value) + when IPAddr + return super unless ['inet','cidr'].includes? column.sql_type + PostgreSQLColumn.cidr_to_string(value) + else + super + end + end + + # Quotes strings for use in SQL input. + def quote_string(s) #:nodoc: + @connection.escape(s) + end + + # Checks the following cases: + # + # - table_name + # - "table.name" + # - schema_name.table_name + # - schema_name."table.name" + # - "schema.name".table_name + # - "schema.name"."table.name" + def quote_table_name(name) + schema, name_part = extract_pg_identifier_from_name(name.to_s) + + unless name_part + quote_column_name(schema) + else + table_name, name_part = extract_pg_identifier_from_name(name_part) + "#{quote_column_name(schema)}.#{quote_column_name(table_name)}" + end + end + + # Quotes column names for use in SQL queries. + def quote_column_name(name) #:nodoc: + PGconn.quote_ident(name.to_s) + 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 + end + end + end +end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb b/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb new file mode 100644 index 0000000000..16da3ea732 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql/referential_integrity.rb @@ -0,0 +1,22 @@ +module ActiveRecord + module ConnectionAdapters + class PostgreSQLAdapter < AbstractAdapter + module ReferentialIntegrity + def supports_disable_referential_integrity? #:nodoc: + true + end + + def disable_referential_integrity #: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 + end + end + end +end diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb new file mode 100644 index 0000000000..60f01c297e --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb @@ -0,0 +1,446 @@ +module ActiveRecord + module ConnectionAdapters + class PostgreSQLAdapter < AbstractAdapter + module SchemaStatements + # Drops the database specified on the +name+ attribute + # and creates it again using the provided +options+. + def recreate_database(name, options = {}) #:nodoc: + drop_database(name) + create_database(name, options) + end + + # Create a new PostgreSQL database. Options include <tt>:owner</tt>, <tt>:template</tt>, + # <tt>:encoding</tt>, <tt>:collation</tt>, <tt>:ctype</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 :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 + + # Drops a PostgreSQL database. + # + # Example: + # drop_database 'matt_development' + def drop_database(name) #:nodoc: + execute "DROP DATABASE IF EXISTS #{quote_table_name(name)}" + end + + # Returns the list of all tables in the schema search path or a specified schema. + def tables(name = nil) + query(<<-SQL, 'SCHEMA').map { |row| row[0] } + SELECT tablename + FROM pg_tables + WHERE schemaname = ANY (current_schemas(false)) + SQL + end + + # Returns true if table exists. + # If the schema is not specified as part of +name+ then it will only find tables within + # the current schema search path (regardless of permissions to access tables in other schemas) + def table_exists?(name) + schema, table = Utils.extract_schema_and_table(name.to_s) + return false unless table + + binds = [[nil, table]] + binds << [nil, schema] if schema + + exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0 + SELECT COUNT(*) + FROM pg_class c + LEFT JOIN pg_namespace n ON n.oid = c.relnamespace + WHERE c.relkind in ('v','r') + AND c.relname = '#{table.gsub(/(^"|"$)/,'')}' + AND n.nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'} + SQL + end + + # Returns true if schema exists. + def schema_exists?(name) + exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0 + SELECT COUNT(*) + FROM pg_namespace + WHERE nspname = '#{name}' + SQL + end + + # Returns an array of indexes for the given table. + def indexes(table_name, name = nil) + result = query(<<-SQL, 'SCHEMA') + SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid + FROM pg_class t + INNER JOIN pg_index d ON t.oid = d.indrelid + INNER JOIN pg_class i ON d.indexrelid = i.oid + WHERE i.relkind = 'i' + AND d.indisprimary = 'f' + AND t.relname = '#{table_name}' + AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (current_schemas(false)) ) + ORDER BY i.relname + SQL + + result.map do |row| + index_name = row[0] + unique = row[1] == 't' + indkey = row[2].split(" ") + inddef = row[3] + oid = row[4] + + columns = Hash[query(<<-SQL, "Columns for index #{row[0]} on #{table_name}")] + SELECT a.attnum, a.attname + FROM pg_attribute a + WHERE a.attrelid = #{oid} + AND a.attnum IN (#{indkey.join(",")}) + SQL + + column_names = columns.values_at(*indkey).compact + + # add info on sort order for columns (only desc order is explicitly specified, asc is the default) + desc_order_columns = inddef.scan(/(\w+) DESC/).flatten + orders = desc_order_columns.any? ? Hash[desc_order_columns.map {|order_column| [order_column, :desc]}] : {} + where = inddef.scan(/WHERE (.+)$/).flatten[0] + + column_names.empty? ? nil : IndexDefinition.new(table_name, index_name, unique, column_names, [], orders, where) + end.compact + end + + # Returns the list of all column definitions for a table. + def columns(table_name) + # Limit, precision, and scale are all handled by the superclass. + column_definitions(table_name).map do |column_name, type, default, notnull, oid, fmod| + oid = OID::TYPE_MAP.fetch(oid.to_i, fmod.to_i) { + OID::Identity.new + } + PostgreSQLColumn.new(column_name, default, oid, type, notnull == 'f') + end + end + + # Returns the current database name. + def current_database + query('select current_database()', 'SCHEMA')[0][0] + end + + # Returns the current schema name. + def current_schema + query('SELECT current_schema', 'SCHEMA')[0][0] + end + + # Returns the current database encoding format. + def encoding + query(<<-end_sql, 'SCHEMA')[0][0] + SELECT pg_encoding_to_char(pg_database.encoding) FROM pg_database + WHERE pg_database.datname LIKE '#{current_database}' + end_sql + end + + # Returns the current database collation. + def collation + query(<<-end_sql, 'SCHEMA')[0][0] + SELECT pg_database.datcollate FROM pg_database WHERE pg_database.datname LIKE '#{current_database}' + end_sql + end + + # Returns the current database ctype. + def ctype + query(<<-end_sql, 'SCHEMA')[0][0] + SELECT pg_database.datctype FROM pg_database WHERE pg_database.datname LIKE '#{current_database}' + end_sql + end + + # Returns an array of schema names. + def schema_names + query(<<-SQL, 'SCHEMA').flatten + SELECT nspname + FROM pg_namespace + WHERE nspname !~ '^pg_.*' + AND nspname NOT IN ('information_schema') + ORDER by nspname; + SQL + end + + # Creates a schema for the given schema name. + def create_schema schema_name + execute "CREATE SCHEMA #{schema_name}" + end + + # Drops the schema for the given schema name. + def drop_schema schema_name + execute "DROP SCHEMA #{schema_name} CASCADE" + 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') + @schema_search_path = schema_csv + end + end + + # Returns the active schema search path. + def schema_search_path + @schema_search_path ||= query('SHOW search_path', 'SCHEMA')[0][0] + end + + # Returns the current client message level. + def client_min_messages + query('SHOW client_min_messages', 'SCHEMA')[0][0] + end + + # Set the client message level. + def client_min_messages=(level) + execute("SET client_min_messages TO '#{level}'", 'SCHEMA') + 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: + result = serial_sequence(table_name, pk || 'id') + return nil unless result + result.split('.').last + rescue ActiveRecord::StatementInvalid + "#{table_name}_#{pk || 'id'}_seq" + end + + def serial_sequence(table, column) + result = exec_query(<<-eosql, 'SCHEMA') + SELECT pg_get_serial_sequence('#{table}', '#{column}') + eosql + result.rows.first.first + 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 @logger && pk && !sequence + @logger.warn "#{table} has primary key #{pk} with no default sequence" + end + + if pk && sequence + quoted_sequence = quote_table_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 + 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 = '#{quote_table_name(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 = '#{quote_table_name(table)}'::regclass + AND cons.contype = 'p' + AND def.adsrc ~* 'nextval' + end_sql + end + + [result.first, result.last] + rescue + nil + end + + # Returns just a table's primary key + def primary_key(table) + row = exec_query(<<-end_sql, 'SCHEMA').rows.first + SELECT DISTINCT(attr.attname) + FROM pg_attribute attr + INNER JOIN pg_depend dep ON attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid + INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] + WHERE cons.contype = 'p' + AND dep.refobjid = '#{table}'::regclass + end_sql + + row && row.first + end + + # Renames a table. + # Also renames a table's primary key sequence if the sequence name matches the + # Active Record default. + # + # Example: + # rename_table('octopuses', 'octopi') + def rename_table(name, new_name) + clear_cache! + execute "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}" + pk, seq = pk_and_sequence_for(new_name) + if seq == "#{name}_#{pk}_seq" + new_seq = "#{new_name}_#{pk}_seq" + execute "ALTER TABLE #{quote_table_name(seq)} RENAME TO #{quote_table_name(new_seq)}" + end + 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 = {}) + clear_cache! + add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD COLUMN #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" + add_column_options!(add_column_sql, options) + + execute add_column_sql + end + + # Changes the column of a table. + def change_column(table_name, column_name, type, options = {}) + clear_cache! + quoted_table_name = quote_table_name(table_name) + + execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" + + 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) + clear_cache! + 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) + clear_cache! + 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) + clear_cache! + execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}" + end + + def remove_index!(table_name, index_name) #:nodoc: + execute "DROP INDEX #{quote_table_name(index_name)}" + end + + def rename_index(table_name, old_name, new_name) + execute "ALTER INDEX #{quote_column_name(old_name)} RENAME TO #{quote_table_name(new_name)}" + end + + def index_name_length + 63 + end + + # Maps logical Rails types to PostgreSQL-specific data types. + def type_to_sql(type, limit = nil, precision = nil, scale = nil) + case type.to_s + when 'binary' + # PostgreSQL doesn't support limits on binary (bytea) columns. + # The hard limit is 1Gb, because of a 32-bit size field, and TOAST. + case limit + when nil, 0..0x3fffffff; super(type) + else raise(ActiveRecordError, "No binary type has byte size #{limit}.") + end + when 'integer' + return 'integer' unless limit + + case limit + when 1, 2; 'smallint' + when 3, 4; 'integer' + when 5..8; 'bigint' + else raise(ActiveRecordError, "No integer type has byte size #{limit}. Use a numeric with precision 0 instead.") + end + when 'datetime' + return super unless precision + + case precision + when 0..6; "timestamp(#{precision})" + else raise(ActiveRecordError, "No timestamp type has precision of #{precision}. The allowed range of precision is from 0 to 6") + end + else + super + 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, orders) #:nodoc: + return "DISTINCT #{columns}" if orders.empty? + + # Construct a clean list of column names from the ORDER BY clause, removing + # any ASC/DESC modifiers + order_columns = orders.collect do |s| + s = s.to_sql unless s.is_a?(String) + s.gsub(/\s+(ASC|DESC)\s*(NULLS\s+(FIRST|LAST)\s*)?/i, '') + end + order_columns.delete_if { |c| c.blank? } + order_columns = order_columns.zip((0...order_columns.size).to_a).map { |s,i| "#{s} AS alias_#{i}" } + + "DISTINCT #{columns}, #{order_columns * ', '}" + end + end + end + end +end |