1select @@global.datetime_format; 2@@global.datetime_format 3%Y-%m-%d %H:%i:%s 4select @@session.datetime_format; 5ERROR HY000: Variable 'datetime_format' is a GLOBAL variable 6show global variables like 'datetime_format'; 7Variable_name Value 8datetime_format %Y-%m-%d %H:%i:%s 9show session variables like 'datetime_format'; 10Variable_name Value 11datetime_format %Y-%m-%d %H:%i:%s 12select * from information_schema.global_variables where variable_name='datetime_format'; 13VARIABLE_NAME VARIABLE_VALUE 14DATETIME_FORMAT %Y-%m-%d %H:%i:%s 15select * from information_schema.session_variables where variable_name='datetime_format'; 16VARIABLE_NAME VARIABLE_VALUE 17DATETIME_FORMAT %Y-%m-%d %H:%i:%s 18set global datetime_format="foo"; 19ERROR HY000: Variable 'datetime_format' is a read only variable 20set session datetime_format="foo"; 21ERROR HY000: Variable 'datetime_format' is a read only variable 22