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