1select @@global.date_format; 2@@global.date_format 3%Y-%m-%d 4Warnings: 5Warning 1287 '@@date_format' is deprecated and will be removed in a future release. 6select @@session.date_format; 7ERROR HY000: Variable 'date_format' is a GLOBAL variable 8show global variables like 'date_format'; 9Variable_name Value 10date_format %Y-%m-%d 11show session variables like 'date_format'; 12Variable_name Value 13date_format %Y-%m-%d 14select * from information_schema.global_variables where variable_name='date_format'; 15VARIABLE_NAME VARIABLE_VALUE 16DATE_FORMAT %Y-%m-%d 17select * from information_schema.session_variables where variable_name='date_format'; 18VARIABLE_NAME VARIABLE_VALUE 19DATE_FORMAT %Y-%m-%d 20set global date_format="foo"; 21ERROR HY000: Variable 'date_format' is a read only variable 22set session date_format="foo"; 23ERROR HY000: Variable 'date_format' is a read only variable 24