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