module ActiveRecord::ConnectionAdapters
Constants
- CHARSETS_OF_4BYTES_MAXLEN
Public Class Methods
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 65 def initialize(connection, logger, connection_options, config) super(connection, logger, config) @statements = StatementPool.new(self.class.type_cast_config_to_integer(config[:statement_limit])) if version < '5.0.0' raise "Your version of MySQL (#{full_version.match(/^\d+\.\d+\.\d+/)[0]}) is too old. Active Record supports MySQL >= 5.0." end end
Public Instance Methods
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 228 def begin_db_transaction execute "BEGIN" end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 232 def begin_isolated_db_transaction(isolation) execute "SET TRANSACTION ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}" begin_db_transaction end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 605 def case_sensitive_comparison(table, attribute, column, value) if !value.nil? && column.collation && !column.case_sensitive? table[attribute].eq(Arel::Nodes::Bin.new(Arel::Nodes::BindParam.new)) else super end end
Returns the database character set.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 300 def charset show_variable 'character_set_database' end
Clears the prepared statements cache.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 198 def clear_cache! reload_type_map @statements.clear end
Returns the database collation strategy.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 305 def collation show_variable 'collation_database' end
Create a new MySQL database
with optional :charset
and :collation
. Charset
defaults to utf8.
Example:
create_database 'charset_test', charset: 'latin1', collation: 'latin1_bin' create_database 'matt_development' create_database 'matt_development', charset: :big5
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 279 def create_database(name, options = {}) if options[:collation] execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset] || 'utf8')} COLLATE #{quote_table_name(options[:collation])}" else execute "CREATE DATABASE #{quote_table_name(name)} DEFAULT CHARACTER SET #{quote_table_name(options[:charset] || 'utf8')}" end end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 295 def current_database select_value 'SELECT DATABASE() as db' end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 347 def data_source_exists?(table_name) return false unless table_name.present? schema, name = extract_schema_qualified_name(table_name) sql = "SELECT table_name FROM information_schema.tables " sql << "WHERE table_schema = #{quote(schema)} AND table_name = #{quote(name)}" select_values(sql, 'SCHEMA').any? end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 325 def data_sources sql = "SELECT table_name FROM information_schema.tables " sql << "WHERE table_schema = #{quote(@config[:database])}" select_values(sql, 'SCHEMA') end
Drops a table from the database.
:force
-
Set to
:cascade
to drop dependent objects as well. Defaults to false. :if_exists
-
Set to
true
to only drop the table if it exists. Defaults to false. :temporary
-
Set to
true
to drop temporary table. Defaults to false.
Although this command ignores most options
and the block if
one is given, it can be helpful to provide these in a migration's
change
method so it can be reverted. In that case,
options
and the block will be used by create_table.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 462 def drop_table(table_name, options = {}) create_table_info_cache.delete(table_name) if create_table_info_cache.key?(table_name) execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_table_name(table_name)}#{' CASCADE' if options[:force] == :cascade}" end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 257 def empty_insert_statement_value "VALUES ()" end
Executes the SQL statement in the context of this connection.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 217 def execute(sql, name = nil) log(sql, name) { @connection.query(sql) } end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 207 def explain(arel, binds = []) sql = "EXPLAIN #{to_sql(arel, binds)}" start = Time.now result = exec_query(sql, 'EXPLAIN', binds) elapsed = Time.now - start MySQL::ExplainPrettyPrinter.new.pp(result, elapsed) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 513 def foreign_keys(table_name) raise ArgumentError unless table_name.present? schema, name = extract_schema_qualified_name(table_name) fk_info = select_all " SELECT fk.referenced_table_name as 'to_table' ,fk.referenced_column_name as 'primary_key' ,fk.column_name as 'column' ,fk.constraint_name as 'name' FROM information_schema.key_column_usage fk WHERE fk.referenced_column_name is not null AND fk.table_schema = #{quote(schema)} AND fk.table_name = #{quote(name)} ".strip_heredoc create_table_info = create_table_info(table_name) fk_info.map do |row| options = { column: row['column'], name: row['name'], primary_key: row['primary_key'] } options[:on_update] = extract_foreign_key_action(create_table_info, row['name'], "UPDATE") options[:on_delete] = extract_foreign_key_action(create_table_info, row['name'], "DELETE") ForeignKeyDefinition.new(table_name, row['to_table'], options) end end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 160 def index_algorithms { default: 'ALGORITHM = DEFAULT', copy: 'ALGORITHM = COPY', inplace: 'ALGORITHM = INPLACE' } end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 156 def native_database_types NATIVE_DATABASE_TYPES end
Drops the database specified on the name
attribute and creates
it again using the provided options
.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 265 def recreate_database(name, options = {}) drop_database(name) sql = create_database(name, options) reconnect! sql end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 467 def rename_index(table_name, old_name, new_name) if supports_rename_index? validate_index_length!(table_name, new_name) execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}" else super end end
Renames a table.
Example:
rename_table('octopuses', 'octopi')
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 442 def rename_table(table_name, new_name) execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}" rename_table_indexes(table_name, new_name) end
SHOW VARIABLES LIKE 'name'
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 584 def show_variable(name) select_value("SELECT @@#{name}", 'SCHEMA') rescue ActiveRecord::StatementInvalid nil end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 633 def strict_mode? self.class.type_cast_config_to_boolean(@config.fetch(:strict, true)) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 144 def supports_advisory_locks? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 136 def supports_datetime_with_precision? if mariadb? version >= '5.3.0' else version >= '5.6.4' end end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 120 def supports_explain? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 128 def supports_foreign_keys? true end
Technically MySQL allows to create indexes with the sort order syntax but at the moment (5.5) it doesn't yet implement them
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 112 def supports_index_sort_order? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 124 def supports_indexes_in_create? true end
Returns true, since this connection adapter supports migrations.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 92 def supports_migrations? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 96 def supports_primary_key? true end
Returns true, since this connection adapter supports prepared statement caching.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 106 def supports_statement_cache? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 116 def supports_transaction_isolation? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 132 def supports_views? true end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 336 def table_exists?(table_name) # Update lib/active_record/internal_metadata.rb when this gets removed ActiveSupport::Deprecation.warn(" #table_exists? currently checks both tables and views. This behavior is deprecated and will be changed with Rails 5.1 to only check tables. Use #data_source_exists? instead. ".squish) data_source_exists?(table_name) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 545 def table_options(table_name) create_table_info = create_table_info(table_name) # strip create_definitions and partition_options raw_table_options = create_table_info.sub(/\A.*\n\) /m, '').sub(/\n\/\*!.*\*\/\n\z/m, '').strip # strip AUTO_INCREMENT raw_table_options.sub!(/(ENGINE=\w+)(?: AUTO_INCREMENT=\d+)/, '\1') # strip COMMENT raw_table_options.sub!(/ COMMENT='.+'/, '') raw_table_options end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 332 def truncate(table_name, name = nil) execute "TRUNCATE TABLE #{quote_table_name(table_name)}", name end
Maps logical Rails types to MySQL-specific data types.
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 561 def type_to_sql(type, limit = nil, precision = nil, scale = nil, unsigned = nil) sql = case type.to_s when 'integer' integer_to_sql(limit) when 'text' text_to_sql(limit) when 'blob' binary_to_sql(limit) when 'binary' if (0..0xfff) === limit "varbinary(#{limit})" else binary_to_sql(limit) end else super(type, limit, precision, scale) end sql << ' unsigned' if unsigned && type != :primary_key sql end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 637 def valid_type?(type) !native_database_types[type].nil? end
Protected Instance Methods
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 743 def add_column_sql(table_name, column_name, type, options = {}) td = create_table_definition(table_name) cd = td.new_column_definition(column_name, type, options) schema_creation.accept(AddColumnDefinition.new(cd)) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 705 def add_index_length(option_strings, column_names, options = {}) if options.is_a?(Hash) && length = options[:length] case length when Hash column_names.each {|name| option_strings[name] += "(#{length[name]})" if length.has_key?(name) && length[name].present?} when Integer column_names.each {|name| option_strings[name] += "(#{length})"} end end return option_strings end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 787 def add_index_sql(table_name, column_name, options = {}) index_name, index_type, index_columns, _, index_algorithm, index_using = add_index_options(table_name, column_name, options) index_algorithm[0, 0] = ", " if index_algorithm.present? "ADD #{index_type} INDEX #{quote_column_name(index_name)} #{index_using} (#{index_columns})#{index_algorithm}" end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 798 def add_timestamps_sql(table_name, options = {}) [add_column_sql(table_name, :created_at, :datetime, options), add_column_sql(table_name, :updated_at, :datetime, options)] end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 749 def change_column_sql(table_name, column_name, type, options = {}) column = column_for(table_name, column_name) unless options_include_default?(options) options[:default] = column.default end unless options.has_key?(:null) options[:null] = column.null end td = create_table_definition(table_name) cd = td.new_column_definition(column.name, type, options) schema_creation.accept(ChangeColumnDefinition.new(cd, column.name)) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 693 def extract_precision(sql_type) if /time/ === sql_type super || 0 else super end end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 701 def fetch_type_metadata(sql_type, extra = "") MySQL::TypeMetadata.new(super(sql_type), extra: extra, strict: strict_mode?) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 718 def quoted_columns_for_index(column_names, options = {}) option_strings = Hash[column_names.map {|name| [name, '']}] # add index length option_strings = add_index_length(option_strings, column_names, options) # add index sort order option_strings = add_index_sort_order(option_strings, column_names, options) column_names.map {|name| quote_column_name(name) + option_strings[name]} end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 779 def remove_column_sql(table_name, column_name, type = nil, options = {}) "DROP #{quote_column_name(column_name)}" end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 783 def remove_columns_sql(table_name, *column_names) column_names.map {|column_name| remove_column_sql(table_name, column_name) } end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 793 def remove_index_sql(table_name, options = {}) index_name = index_name_for_remove(table_name, options) "DROP INDEX #{index_name}" end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 802 def remove_timestamps_sql(table_name, options = {}) [remove_column_sql(table_name, :updated_at), remove_column_sql(table_name, :created_at)] end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 765 def rename_column_sql(table_name, column_name, new_column_name) column = column_for(table_name, column_name) options = { default: column.default, null: column.null, auto_increment: column.auto_increment? } current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'", 'SCHEMA')["Type"] td = create_table_definition(table_name) cd = td.new_column_definition(new_column_name, current_type, options) schema_creation.accept(ChangeColumnDefinition.new(cd, column.name)) end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 730 def translate_exception(exception, message) case error_number(exception) when 1062 RecordNotUnique.new(message) when 1452 InvalidForeignKey.new(message) when 1406 ValueTooLong.new(message) else super end end
Private Instance Methods
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 613 def can_perform_case_insensitive_comparison_for?(column) column.case_sensitive? end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 827 def configure_connection variables = @config.fetch(:variables, {}).stringify_keys # By default, MySQL 'where id is null' selects the last inserted id; Turn this off. variables['sql_auto_is_null'] = 0 # Increase timeout so the server doesn't disconnect us. wait_timeout = @config[:wait_timeout] wait_timeout = 2147483 unless wait_timeout.is_a?(Integer) variables['wait_timeout'] = self.class.type_cast_config_to_integer(wait_timeout) defaults = [':default', :default].to_set # Make MySQL reject illegal values rather than truncating or blanking them, see # http://dev.mysql.com/doc/refman/5.7/en/sql-mode.html#sqlmode_strict_all_tables # If the user has provided another value for sql_mode, don't replace it. if sql_mode = variables.delete('sql_mode') sql_mode = quote(sql_mode) elsif !defaults.include?(strict_mode?) if strict_mode? sql_mode = "CONCAT(@@sql_mode, ',STRICT_ALL_TABLES')" else sql_mode = "REPLACE(@@sql_mode, 'STRICT_TRANS_TABLES', '')" sql_mode = "REPLACE(#{sql_mode}, 'STRICT_ALL_TABLES', '')" sql_mode = "REPLACE(#{sql_mode}, 'TRADITIONAL', '')" end sql_mode = "CONCAT(#{sql_mode}, ',NO_AUTO_VALUE_ON_ZERO')" end sql_mode_assignment = "@@SESSION.sql_mode = #{sql_mode}, " if sql_mode # NAMES does not have an equals sign, see # http://dev.mysql.com/doc/refman/5.7/en/set-statement.html#id944430 # (trailing comma because variable_assignments will always have content) if @config[:encoding] encoding = "NAMES #{@config[:encoding]}" encoding << " COLLATE #{@config[:collation]}" if @config[:collation] encoding << ", " end # Gather up all of the SET variables... variable_assignments = variables.map do |k, v| if defaults.include?(v) "@@SESSION.#{k} = DEFAULT" # Sets the value to the global or compile default elsif !v.nil? "@@SESSION.#{k} = #{quote(v)}" end # or else nil; compact to clear nils out end.compact.join(', ') # ...and send them all in one query @connection.query "SET #{encoding} #{sql_mode_assignment} #{variable_assignments}" end
MySQL is too stupid to create a temporary table for use subquery, so we have to give it some prompting in the form of a subsubquery. Ugh!
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 810 def subquery_for(key, select) subsubselect = select.clone subsubselect.projections = [key] # Materialize subquery by adding distinct # to work with MySQL 5.7.6 which sets optimizer_switch='derived_merge=on' subsubselect.distinct unless select.limit || select.offset || select.orders.any? subselect = Arel::SelectManager.new(select.engine) subselect.project Arel.sql(key.name) subselect.from subsubselect.as('__active_record_temp') end
# File lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 823 def supports_rename_index? mariadb? ? false : version >= '5.7.6' end