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:
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:host - Defaults to “localhost”.
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:port - Defaults to 3306.
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:socket - Defaults to “/tmp/mysql.sock”.
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:username - Defaults to “root”
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:password - Defaults to nothing.
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:database - The name of the database. No default, must be provided.
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:encoding - (Optional) Sets the client encoding by executing “SET NAMES <encoding>” after connection.
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:reconnect - Defaults to false (See MySQL documentation: dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html).
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:sslca - Necessary to use MySQL with an SSL connection.
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:sslkey - Necessary to use MySQL with an SSL connection.
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:sslcert - Necessary to use MySQL with an SSL connection.
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:sslcapath - Necessary to use MySQL with an SSL connection.
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:sslcipher - Necessary to use MySQL with an SSL connection.
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ADAPTER_NAME | = | 'MySQL' |
LOST_CONNECTION_ERROR_MESSAGES | = | [ "Server shutdown in progress", "Broken pipe", "Lost connection to MySQL server during query", "MySQL server has gone away" ] |
QUOTED_FALSE | = | '1', '0' |
NATIVE_DATABASE_TYPES | = | { :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY", :string => { :name => "varchar", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "int", :limit => 4 }, :float => { :name => "float" }, :decimal => { :name => "decimal" }, :datetime => { :name => "datetime" }, :timestamp => { :name => "datetime" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "blob" }, :boolean => { :name => "tinyint", :limit => 1 } } |
ENCODINGS | = | { "armscii8" => nil, "ascii" => Encoding::US_ASCII, "big5" => Encoding::Big5, "binary" => Encoding::ASCII_8BIT, "cp1250" => Encoding::Windows_1250, "cp1251" => Encoding::Windows_1251, "cp1256" => Encoding::Windows_1256, "cp1257" => Encoding::Windows_1257, "cp850" => Encoding::CP850, "cp852" => Encoding::CP852, "cp866" => Encoding::IBM866, "cp932" => Encoding::Windows_31J, "dec8" => nil, "eucjpms" => Encoding::EucJP_ms, "euckr" => Encoding::EUC_KR, "gb2312" => Encoding::EUC_CN, "gbk" => Encoding::GBK, "geostd8" => nil, "greek" => Encoding::ISO_8859_7, "hebrew" => Encoding::ISO_8859_8, "hp8" => nil, "keybcs2" => nil, "koi8r" => Encoding::KOI8_R, "koi8u" => Encoding::KOI8_U, "latin1" => Encoding::ISO_8859_1, "latin2" => Encoding::ISO_8859_2, "latin5" => Encoding::ISO_8859_9, "latin7" => Encoding::ISO_8859_13, "macce" => Encoding::MacCentEuro, "macroman" => Encoding::MacRoman, "sjis" => Encoding::SHIFT_JIS, "swe7" => nil, "tis620" => Encoding::TIS_620, "ucs2" => Encoding::UTF_16BE, "ujis" => Encoding::EucJP_ms, "utf8" => Encoding::UTF_8, "utf8mb4" => Encoding::UTF_8, } |
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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 187 def initialize(connection, logger, connection_options, config) super(connection, logger) @connection_options, @config = connection_options, config @quoted_column_names, @quoted_table_names = {}, {} @statements = {} @client_encoding = nil connect end
CONNECTION MANAGEMENT ====================================
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 288 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 678 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.
Clears the prepared statements cache.
Get the client encoding for this database
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 391 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.
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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 559 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
Disconnects from the database if already connected. Otherwise, this method does nothing.
Returns just a table’s primary key
QUOTING ==================================================
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 236 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
Renames a table.
Example:
rename_table('octopuses', 'octopi')
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 317 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
DATABASE STATEMENTS ======================================
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 328 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’
Returns true, since this connection adapter supports prepared statement caching.
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 596 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
Maps logical Rails types to MySQL-specific data types.
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 697 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 781 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 826 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 793 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 755 def quoted_columns_for_index(column_names, options = {}) length = options[:length] if options.is_a?(Hash) quoted_column_names = 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 810 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 activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 768 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