1.9.3. Running MySQL in ANSI Mode
You can tell mysqld to run in ANSI mode with
the --ansi startup option. Running the server
in ANSI mode is the same as starting it with the following
options:
--transaction-isolation=SERIALIZABLE --sql-mode=ANSI
As of MySQL 4.1.1, you can achieve the same effect at runtime by
executing these two statements:
SET GLOBAL TRANSACTION ISOLATION LEVEL SERIALIZABLE;
SET GLOBAL sql_mode = 'ANSI';
You can see that setting the sql_mode system
variable to 'ANSI' enables all SQL mode
options that are relevant for ANSI mode as follows:
mysql> SET GLOBAL sql_mode='ANSI';
mysql> SELECT @@global.sql_mode;
-> 'REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI'
Note that running the server in ANSI mode with
--ansi is not quite the same as setting the SQL
mode to 'ANSI'. The --ansi
option affects the SQL mode and also sets the transaction
isolation level. Setting the SQL mode to
'ANSI' has no effect on the isolation level.
See Section 5.2.1, “mysqld Command Options”, and
Section 1.9.2, “Selecting SQL Modes”.
