You can tell mysqld to use the ANSI mode with the --ansi startup option. See Server options.
Running the server in ANSI mode is the same as starting it with these options:
--sql-mode=REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ONLY_FULL_GROUP_BY --transaction-isolation=SERIALIZABLE
In MySQL 4.1, you can achieve the same effect with these two statements:
SET GLOBAL TRANSACTION ISOLATION LEVEL SERIALIZABLE; SET GLOBAL sql_mode = "REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ONLY_FULL_GROUP_BY";
See SQL mode.
In MySQL 4.1.1, the sql_mode options shown can be also be set with:
SET GLOBAL sql_mode="ansi";
In this case, the value of the sql_mode variable will be set to all options that are relevant for ANSI mode. You can check the result by doing:
mysql> SET GLOBAL sql_mode="ansi"; mysql> SELECT @@GLOBAL.sql_mode; -> "REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ONLY_FULL_GROUP_BY,ANSI"