Returns just a table’s primary key
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 768 def primary_key(table) pk_and_sequence = pk_and_sequence_for(table) pk_and_sequence && pk_and_sequence.first end
The MySQL adapter will work with both Ruby/MySQL, which is a Ruby-based MySQL adapter that comes bundled with Active Record, and with the faster C-based MySQL/Ruby adapter (available both as a gem and from www.tmtm.org/en/mysql/ruby/).
Options:
:host - Defaults to "localhost".
:port - Defaults to 3306.
:socket - Defaults to "/tmp/mysql.sock".
:username - Defaults to "root"
:password - Defaults to nothing.
:database - The name of the database. No default, must be provided.
:encoding - (Optional) Sets the client encoding by executing "SET NAMES <encoding>" after connection.
:reconnect - Defaults to false (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html).
:sslca - Necessary to use MySQL with an SSL connection.
:sslkey - Necessary to use MySQL with an SSL connection.
:sslcert - Necessary to use MySQL with an SSL connection.
:sslcapath - Necessary to use MySQL with an SSL connection.
:sslcipher - Necessary to use MySQL with an SSL connection.
Taken from here:
https://github.com/tmtm/ruby-mysql/blob/master/lib/mysql/charset.rb
Author: TOMITA Masahiro <tommy@tmtm.org>
By default, the MysqlAdapter will consider all columns of type tinyint(1) as boolean. If you wish to disable this emulation (which was the default behavior in versions 0.13.1 and earlier) you can add the following line to your application.rb file:
ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = false
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 160 cattr_accessor :emulate_booleans
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 220 def initialize(connection, logger, connection_options, config) super(connection, logger) @connection_options, @config = connection_options, config @quoted_column_names, @quoted_table_names = {}, {} @statements = {} @statements = StatementPool.new(@connection, config.fetch(:statement_limit) { 1000 }) @client_encoding = nil connect end
CONNECTION MANAGEMENT ====================================
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 323 def active? if @connection.respond_to?(:stat) @connection.stat else @connection.query 'select 1' end # mysql-ruby doesn't raise an exception when stat fails. if @connection.respond_to?(:errno) @connection.errno.zero? else true end rescue Mysql::Error false end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 701 def add_column(table_name, column_name, type, options = {}) execute("ALTER TABLE #{quote_table_name(table_name)} #{add_column_sql(table_name, column_name, type, options)}") end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 742 def add_column_position!(sql, options) if options[:first] sql << " FIRST" elsif options[:after] sql << " AFTER #{quote_column_name(options[:after])}" end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 773 def case_sensitive_equality_operator "= BINARY" end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 778 def case_sensitive_modifier(node) Arel::Nodes::Bin.new(node) end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 710 def change_column_null(table_name, column_name, null, default = nil) column = column_for(table_name, column_name) 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 change_column table_name, column_name, column.sql_type, :null => null end
Returns the database character set.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 612 def charset show_variable 'character_set_database' end
Clears the prepared statements cache.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 371 def clear_cache! @statements.clear end
Get the client encoding for this database
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 423 def client_encoding return @client_encoding if @client_encoding result = exec_query( "SHOW VARIABLES WHERE Variable_name = 'character_set_client'", 'SCHEMA') @client_encoding = ENCODINGS[result.rows.last.last] end
Returns the database collation strategy.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 617 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/mysql_adapter.rb, line 591 def create_database(name, options = {}) if options[:collation] execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`" else execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`" end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 515 def create_savepoint execute("SAVEPOINT #{current_savepoint_name}") end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 607 def current_database select_value 'SELECT DATABASE() as db' end
Disconnects from the database if already connected. Otherwise, this method does nothing.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 348 def disconnect! @connection.close rescue nil end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 642 def drop_table(table_name, options = {}) super(table_name, options) end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 488 def exec_delete(sql, name, binds) log(sql, name, binds) do exec_stmt(sql, name, binds) do |cols, stmt| stmt.affected_rows end end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 432 def exec_query(sql, name = 'SQL', binds = []) log(sql, name, binds) do exec_stmt(sql, name, binds) do |cols, stmt| ActiveRecord::Result.new(cols, stmt.to_a) if cols end end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 440 def last_inserted_id(result) @connection.insert_id end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 782 def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) where_sql end
Returns just a table’s primary key
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 768 def primary_key(table) pk_and_sequence = pk_and_sequence_for(table) pk_and_sequence && pk_and_sequence.first end
QUOTING ==================================================
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 271 def quote(value, column = nil) if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary) s = column.class.string_to_binary(value).unpack("H*")[0] "x'#{s}'" elsif value.kind_of?(BigDecimal) value.to_s("F") else super end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 304 def quoted_false QUOTED_FALSE end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 300 def quoted_true QUOTED_TRUE end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 340 def reconnect! disconnect! clear_cache! connect end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 523 def release_savepoint execute("RELEASE SAVEPOINT #{current_savepoint_name}") end
Renames a table.
Example:
rename_table('octopuses', 'octopi')
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 682 def rename_table(table_name, new_name) execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}" end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 352 def reset! if @connection.respond_to?(:change_user) # See http://bugs.mysql.com/bug.php?id=33540 -- the workaround way to # reset the connection is to change the user to the same user. @connection.change_user(@config[:username], @config[:password], @config[:database]) configure_connection end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 519 def rollback_to_savepoint execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}") end
DATABASE STATEMENTS ======================================
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 363 def select_rows(sql, name = nil) @connection.query_with_result = true rows = exec_without_stmt(sql, name).rows @connection.more_results && @connection.next_result # invoking stored procedures with CLIENT_MULTI_RESULTS requires this to tidy up else connection will be dropped rows end
SHOW VARIABLES LIKE ‘name’
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 751 def show_variable(name) variables = select_all("SHOW VARIABLES LIKE '#{name}'") variables.first['Value'] unless variables.empty? end
Returns true, since this connection adapter supports prepared statement caching.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 245 def supports_statement_cache? true end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 628 def table_exists?(name) return true if super name = name.to_s schema, table = name.split('.', 2) unless table # A table was provided without a schema table = schema schema = nil end tables(nil, schema).include? table end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 282 def type_cast(value, column) return super unless value == true || value == false value ? 1 : 0 end
Maps logical Rails types to MySQL-specific data types.
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 729 def type_to_sql(type, limit = nil, precision = nil, scale = nil) return super unless type.to_s == 'integer' case limit when 1; 'tinyint' when 2; 'smallint' when 3; 'mediumint' when nil, 4, 11; 'int(11)' # compatibility with MySQL default when 5..8; 'bigint' else raise(ActiveRecordError, "No integer type has byte size #{limit}") end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 813 def add_column_sql(table_name, column_name, type, options = {}) add_column_sql = "ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" add_column_options!(add_column_sql, options) add_column_position!(add_column_sql, options) add_column_sql end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 858 def add_index_sql(table_name, column_name, options = {}) index_name, index_type, index_columns = add_index_options(table_name, column_name, options) "ADD #{index_type} INDEX #{index_name} (#{index_columns})" end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 868 def add_timestamps_sql(table_name) [add_column_sql(table_name, :created_at, :datetime), add_column_sql(table_name, :updated_at, :datetime)] end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 825 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 change_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" add_column_options!(change_column_sql, options) add_column_position!(change_column_sql, options) change_column_sql end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 787 def quoted_columns_for_index(column_names, options = {}) length = options[:length] if options.is_a?(Hash) case length when Hash column_names.map {|name| length[name] ? "#{quote_column_name(name)}(#{length[name]})" : quote_column_name(name) } when Fixnum column_names.map {|name| "#{quote_column_name(name)}(#{length})"} else column_names.map {|name| quote_column_name(name) } end end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 820 def remove_column_sql(table_name, *column_names) columns_for_remove(table_name, *column_names).map {|column_name| "DROP #{column_name}" } end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 863 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/mysql_adapter.rb, line 872 def remove_timestamps_sql(table_name) [remove_column_sql(table_name, :updated_at), remove_column_sql(table_name, :created_at)] end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 842 def rename_column_sql(table_name, column_name, new_column_name) options = {} if column = columns(table_name).find { |c| c.name == column_name.to_s } options[:default] = column.default options[:null] = column.null else raise ActiveRecordError, "No such column: #{table_name}.#{column_name}" end current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"] rename_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}" add_column_options!(rename_column_sql, options) rename_column_sql end
# File lib/active_record/connection_adapters/mysql_adapter.rb, line 800 def translate_exception(exception, message) return super unless exception.respond_to?(:errno) case exception.errno when 1062 RecordNotUnique.new(message, exception) when 1452 InvalidForeignKey.new(message, exception) else super end end
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