# File lib/sequel/adapters/shared/mysql.rb, line 416 def primary_key_from_schema(table) schema(table).select{|a| a[1][:primary_key]}.map{|a| a[0]} end
module Sequel::MySQL::DatabaseMethods
Methods shared by Database instances that connect to MySQL, currently supported by the native and JDBC adapters.
Constants
- AUTO_INCREMENT
- CAST_TYPES
- COLUMN_DEFINITION_ORDER
- DATABASE_ERROR_REGEXPS
- MYSQL_TIMESTAMP_RE
- PRIMARY
Public Instance Methods
MySQL's cast rules are restrictive in that you can't just cast to any possible database type.
# File lib/sequel/adapters/shared/mysql.rb, line 46 def cast_type_literal(type) CAST_TYPES[type] || super end
Commit an existing prepared transaction with the given transaction identifier string.
# File lib/sequel/adapters/shared/mysql.rb, line 52 def commit_prepared_transaction(transaction_id) run("XA COMMIT #{literal(transaction_id)}") end
MySQL uses the :mysql database type
# File lib/sequel/adapters/shared/mysql.rb, line 57 def database_type :mysql end
Use the Information Schema's KEY_COLUMN_USAGE table to get basic information on foreign key columns, but include the constraint name.
# File lib/sequel/adapters/shared/mysql.rb, line 64 def foreign_key_list(table, opts={}) m = output_identifier_meth im = input_identifier_meth ds = metadata_dataset. from(:INFORMATION_SCHEMA__KEY_COLUMN_USAGE). where(:TABLE_NAME=>im.call(table), :TABLE_SCHEMA=>Sequel.function(:DATABASE)). exclude(:CONSTRAINT_NAME=>'PRIMARY'). exclude(:REFERENCED_TABLE_NAME=>nil). select(:CONSTRAINT_NAME___name, :COLUMN_NAME___column, :REFERENCED_TABLE_NAME___table, :REFERENCED_COLUMN_NAME___key) h = {} ds.each do |row| if r = h[row[:name]] r[:columns] << m.call(row[:column]) r[:key] << m.call(row[:key]) else h[row[:name]] = {:name=>m.call(row[:name]), :columns=>[m.call(row[:column])], :table=>m.call(row[:table]), :key=>[m.call(row[:key])]} end end h.values end
MySQL namespaces indexes per table.
# File lib/sequel/adapters/shared/mysql.rb, line 87 def global_index_namespace? false end
Use SHOW INDEX FROM to get the index information for the table.
By default partial indexes are not included, you can use the option :partial to override this.
# File lib/sequel/adapters/shared/mysql.rb, line 96 def indexes(table, opts={}) indexes = {} remove_indexes = [] m = output_identifier_meth im = input_identifier_meth metadata_dataset.with_sql("SHOW INDEX FROM ?", SQL::Identifier.new(im.call(table))).each do |r| name = r[:Key_name] next if name == PRIMARY name = m.call(name) remove_indexes << name if r[:Sub_part] && ! opts[:partial] i = indexes[name] ||= {:columns=>[], :unique=>r[:Non_unique] != 1} i[:columns] << m.call(r[:Column_name]) end indexes.reject{|k,v| remove_indexes.include?(k)} end
Rollback an existing prepared transaction with the given transaction identifier string.
# File lib/sequel/adapters/shared/mysql.rb, line 114 def rollback_prepared_transaction(transaction_id) run("XA ROLLBACK #{literal(transaction_id)}") end
Get version of MySQL server, used for determined capabilities.
# File lib/sequel/adapters/shared/mysql.rb, line 119 def server_version @server_version ||= begin m = /(\d+)\.(\d+)\.(\d+)/.match(get(SQL::Function.new(:version))) (m[1].to_i * 10000) + (m[2].to_i * 100) + m[3].to_i end end
MySQL supports CREATE TABLE IF NOT EXISTS syntax.
# File lib/sequel/adapters/shared/mysql.rb, line 127 def supports_create_table_if_not_exists? true end
MySQL supports prepared transactions (two-phase commit) using XA
# File lib/sequel/adapters/shared/mysql.rb, line 132 def supports_prepared_transactions? server_version >= 50000 end
MySQL supports savepoints
# File lib/sequel/adapters/shared/mysql.rb, line 137 def supports_savepoints? server_version >= 50000 end
MySQL doesn't support savepoints inside prepared transactions in from 5.5.12 to 5.5.23, see bugs.mysql.com/bug.php?id=64374
# File lib/sequel/adapters/shared/mysql.rb, line 143 def supports_savepoints_in_prepared_transactions? super && (server_version <= 50512 || server_version >= 50523) end
MySQL supports transaction isolation levels
# File lib/sequel/adapters/shared/mysql.rb, line 148 def supports_transaction_isolation_levels? true end
Return an array of symbols specifying table names in the current database.
Options:
-
:server - Set the server to use
# File lib/sequel/adapters/shared/mysql.rb, line 156 def tables(opts={}) full_tables('BASE TABLE', opts) end
Changes the database in use by issuing a USE statement. I would be very careful if I used this.
# File lib/sequel/adapters/shared/mysql.rb, line 162 def use(db_name) disconnect @opts[:database] = db_name if self << "USE #{db_name}" @schemas = {} self end
Return an array of symbols specifying view names in the current database.
Options:
-
:server - Set the server to use
# File lib/sequel/adapters/shared/mysql.rb, line 173 def views(opts={}) full_tables('VIEW', opts) end
Private Instance Methods
Use MySQL specific syntax for some alter table operations.
# File lib/sequel/adapters/shared/mysql.rb, line 180 def alter_table_op_sql(table, op) case op[:op] when :add_column if related = op.delete(:table) sql = super op[:table] = related op[:key] ||= primary_key_from_schema(related) sql << ", ADD FOREIGN KEY (#{quote_identifier(op[:name])})#{column_references_sql(op)}" else super end when :rename_column, :set_column_type, :set_column_null, :set_column_default o = op[:op] opts = schema(table).find{|x| x.first == op[:name]} opts = opts ? opts.last.dup : {} opts[:name] = o == :rename_column ? op[:new_name] : op[:name] opts[:type] = o == :set_column_type ? op[:type] : opts[:db_type] opts[:null] = o == :set_column_null ? op[:null] : opts[:allow_null] opts[:default] = o == :set_column_default ? op[:default] : opts[:ruby_default] opts.delete(:default) if opts[:default] == nil opts.delete(:primary_key) unless op[:type] || opts[:type] raise Error, "cannot determine database type to use for CHANGE COLUMN operation" end opts = op.merge(opts) opts.delete(:auto_increment) if op[:auto_increment] == false "CHANGE COLUMN #{quote_identifier(op[:name])} #{column_definition_sql(opts)}" when :drop_constraint case op[:type] when :primary_key "DROP PRIMARY KEY" when :foreign_key name = op[:name] || foreign_key_name(table, op[:columns]) "DROP FOREIGN KEY #{quote_identifier(name)}" when :unique "DROP INDEX #{quote_identifier(op[:name])}" end when :add_constraint if op[:type] == :foreign_key op[:key] ||= primary_key_from_schema(op[:table]) end super else super end end
MySQL server requires table names when dropping indexes.
# File lib/sequel/adapters/shared/mysql.rb, line 228 def alter_table_sql(table, op) case op[:op] when :drop_index "#{drop_index_sql(table, op)} ON #{quote_schema_table(table)}" when :drop_constraint if op[:type] == :primary_key if (pk = primary_key_from_schema(table)).length == 1 return [alter_table_sql(table, {:op=>:rename_column, :name=>pk.first, :new_name=>pk.first, :auto_increment=>false}), super] end end super else super end end
Use MySQL specific AUTO_INCREMENT text.
# File lib/sequel/adapters/shared/mysql.rb, line 281 def auto_increment_sql AUTO_INCREMENT end
MySQL needs to set transaction isolation before begining a transaction
# File lib/sequel/adapters/shared/mysql.rb, line 286 def begin_new_transaction(conn, opts) set_transaction_isolation(conn, opts) log_connection_execute(conn, begin_transaction_sql) end
Use XA START to start a new prepared transaction if the :prepare option is given.
# File lib/sequel/adapters/shared/mysql.rb, line 293 def begin_transaction(conn, opts={}) if (s = opts[:prepare]) && (th = _trans(conn))[:savepoint_level] == 0 log_connection_execute(conn, "XA START #{literal(s)}") th[:savepoint_level] += 1 else super end end
The order of the column definition, as an array of symbols.
# File lib/sequel/adapters/shared/mysql.rb, line 303 def column_definition_order COLUMN_DEFINITION_ORDER end
MySQL doesn't allow default values on text columns, so ignore if it the generic text type is used
# File lib/sequel/adapters/shared/mysql.rb, line 309 def column_definition_sql(column) column.delete(:default) if column[:type] == File || (column[:type] == String && column[:text] == true) super end
Handle MySQL specific default format.
# File lib/sequel/adapters/shared/mysql.rb, line 245 def column_schema_normalize_default(default, type) if column_schema_default_string_type?(type) return if [:date, :datetime, :time].include?(type) && MYSQL_TIMESTAMP_RE.match(default) default = "'#{default.gsub("'", "''").gsub('\\', '\\\\')}'" end super(default, type) end
Don't allow combining adding foreign key operations with other operations, since in some cases adding a foreign key constraint in the same query as other operations results in MySQL error 150.
# File lib/sequel/adapters/shared/mysql.rb, line 256 def combinable_alter_table_op?(op) super && !(op[:op] == :add_constraint && op[:type] == :foreign_key) && !(op[:op] == :drop_constraint && op[:type] == :primary_key) end
Prepare the XA transaction for a two-phase commit if the :prepare option is given.
# File lib/sequel/adapters/shared/mysql.rb, line 316 def commit_transaction(conn, opts={}) if (s = opts[:prepare]) && _trans(conn)[:savepoint_level] <= 1 log_connection_execute(conn, "XA END #{literal(s)}") log_connection_execute(conn, "XA PREPARE #{literal(s)}") else super end end
Use MySQL specific syntax for engine type and character encoding
# File lib/sequel/adapters/shared/mysql.rb, line 326 def create_table_sql(name, generator, options = {}) engine = options.fetch(:engine, Sequel::MySQL.default_engine) charset = options.fetch(:charset, Sequel::MySQL.default_charset) collate = options.fetch(:collate, Sequel::MySQL.default_collate) generator.constraints.sort_by{|c| (c[:type] == :primary_key) ? -1 : 1} # Proc for figuring out the primary key for a given table. key_proc = lambda do |t| if t == name if pk = generator.primary_key_name [pk] elsif !(pkc = generator.constraints.select{|con| con[:type] == :primary_key}).empty? pkc.first[:columns] end else primary_key_from_schema(t) end end # Manually set the keys, since MySQL requires one, it doesn't use the primary # key if none are specified. generator.constraints.each do |c| if c[:type] == :foreign_key c[:key] ||= key_proc.call(c[:table]) end end # Split column constraints into table constraints in some cases: # * foreign key - Always # * unique, primary_key - Only if constraint has a name generator.columns.each do |c| if t = c.delete(:table) same_table = t == name k = c[:key] key ||= key_proc.call(t) if same_table && !k.nil? generator.constraints.unshift(:type=>:unique, :columns=>Array(k)) end generator.foreign_key([c[:name]], t, c.merge(:name=>c[:foreign_key_constraint_name], :type=>:foreign_key, :key=>key)) end end "#{super}#{" ENGINE=#{engine}" if engine}#{" DEFAULT CHARSET=#{charset}" if charset}#{" DEFAULT COLLATE=#{collate}" if collate}" end
# File lib/sequel/adapters/shared/mysql.rb, line 380 def database_error_regexps DATABASE_ERROR_REGEXPS end
Backbone of the tables and views support using SHOW FULL TABLES.
# File lib/sequel/adapters/shared/mysql.rb, line 385 def full_tables(type, opts) m = output_identifier_meth metadata_dataset.with_sql('SHOW FULL TABLES').server(opts[:server]).map{|r| m.call(r.values.first) if r.delete(:Table_type) == type}.compact end
MySQL folds unquoted identifiers to lowercase, so it shouldn't need to upcase identifiers on input.
# File lib/sequel/adapters/shared/mysql.rb, line 391 def identifier_input_method_default nil end
MySQL folds unquoted identifiers to lowercase, so it shouldn't need to upcase identifiers on output.
# File lib/sequel/adapters/shared/mysql.rb, line 396 def identifier_output_method_default nil end
Handle MySQL specific index SQL syntax
# File lib/sequel/adapters/shared/mysql.rb, line 401 def index_definition_sql(table_name, index) index_name = quote_identifier(index[:name] || default_index_name(table_name, index[:columns])) index_type = case index[:type] when :full_text "FULLTEXT " when :spatial "SPATIAL " else using = " USING #{index[:type]}" unless index[:type] == nil "UNIQUE " if index[:unique] end "CREATE #{index_type}INDEX #{index_name}#{using} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}" end
The SQL queries to execute on initial connection
# File lib/sequel/adapters/shared/mysql.rb, line 261 def mysql_connection_setting_sqls sqls = [] # Increase timeout so mysql server doesn't disconnect us # Value used by default is maximum allowed value on Windows. sqls << "SET @@wait_timeout = #{opts[:timeout] || 2147483}" # By default, MySQL 'where id is null' selects the last inserted id sqls << "SET SQL_AUTO_IS_NULL=0" unless opts[:auto_is_null] # If the user has specified one or more sql modes, enable them if sql_mode = opts[:sql_mode] sql_mode = Array(sql_mode).join(',').upcase sqls << "SET sql_mode = '#{sql_mode}'" end sqls end
Parse the schema for the given table to get an array of primary key columns
Rollback the currently open XA transaction
# File lib/sequel/adapters/shared/mysql.rb, line 421 def rollback_transaction(conn, opts={}) if (s = opts[:prepare]) && _trans(conn)[:savepoint_level] <= 1 log_connection_execute(conn, "XA END #{literal(s)}") log_connection_execute(conn, "XA PREPARE #{literal(s)}") log_connection_execute(conn, "XA ROLLBACK #{literal(s)}") else super end end
Recognize MySQL set type.
# File lib/sequel/adapters/shared/mysql.rb, line 432 def schema_column_type(db_type) case db_type when /\Aset/io :set when /\Amediumint/io :integer when /\Amediumtext/io :string else super end end
Use the MySQL specific DESCRIBE syntax to get a table description.
# File lib/sequel/adapters/shared/mysql.rb, line 446 def schema_parse_table(table_name, opts) m = output_identifier_meth(opts[:dataset]) im = input_identifier_meth(opts[:dataset]) table = SQL::Identifier.new(im.call(table_name)) table = SQL::QualifiedIdentifier.new(im.call(opts[:schema]), table) if opts[:schema] metadata_dataset.with_sql("DESCRIBE ?", table).map do |row| row[:auto_increment] = true if row.delete(:Extra).to_s =~ /auto_increment/io row[:allow_null] = row.delete(:Null) == 'YES' row[:default] = row.delete(:Default) row[:primary_key] = row.delete(:Key) == 'PRI' row[:default] = nil if blank_object?(row[:default]) row[:db_type] = row.delete(:Type) row[:type] = schema_column_type(row[:db_type]) [m.call(row.delete(:Field)), row] end end
MySQL can combine multiple alter table ops into a single query.
# File lib/sequel/adapters/shared/mysql.rb, line 464 def supports_combining_alter_table_ops? true end
MySQL supports CREATE OR REPLACE VIEW.
# File lib/sequel/adapters/shared/mysql.rb, line 469 def supports_create_or_replace_view? true end
MySQL does not support named column constraints.
# File lib/sequel/adapters/shared/mysql.rb, line 474 def supports_named_column_constraints? false end
MySQL has both datetime and timestamp classes, most people are going to want datetime
# File lib/sequel/adapters/shared/mysql.rb, line 496 def type_literal_generic_datetime(column) if column[:default] == Sequel::CURRENT_TIMESTAMP :timestamp else :datetime end end
Respect the :size option if given to produce tinyblob, mediumblob, and longblob if :tiny, :medium, or :long is given.
# File lib/sequel/adapters/shared/mysql.rb, line 481 def type_literal_generic_file(column) case column[:size] when :tiny # < 2^8 bytes :tinyblob when :medium # < 2^24 bytes :mediumblob when :long # < 2^32 bytes :longblob else # 2^16 bytes :blob end end
MySQL has both datetime and timestamp classes, most people are going to want datetime
# File lib/sequel/adapters/shared/mysql.rb, line 506 def type_literal_generic_time(column) column[:only_time] ? :time : type_literal_generic_datetime(column) end
MySQL doesn't have a true boolean class, so it uses tinyint(1)
# File lib/sequel/adapters/shared/mysql.rb, line 511 def type_literal_generic_trueclass(column) :'tinyint(1)' end