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