working of group by clause in sql code example

Example 1: GROUP BY clause; this is incompati

mysql> set global sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

mysql> set session sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';

Example 2: group function in sql

--- GROUP FUNCTION | MULTI ROW FUNCTION | AGGREGATE FUNCTION 
--- COUNT , MAX , MIN , SUM , AVG