MySQL 5.6

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE `employee_gb`
(name varchar(50), salary float, dept varchar(50));

INSERT INTO `employee_gb` VALUES('a',1,'dept3'); 
INSERT INTO `employee_gb` VALUES('b',2,'dept4'); 
INSERT INTO `employee_gb` VALUES('c',3,'dept1'); 
INSERT INTO `employee_gb` VALUES('d',4,'dept2'); 
INSERT INTO `employee_gb` VALUES('e',5,'dept2'); 
INSERT INTO `employee_gb` VALUES('g',5,'dept2'); 
INSERT INTO `employee_gb` VALUES('f',6,'dept1'); 
SELECT name, MAX(salary), dept 
FROM `employee_gb`
GROUP BY dept;


name
MAX(salary)
dept


c
6
dept1

d
5
dept2

a
1
dept3

b
2
dept4


select @@sql_mode;


@@sql_mode


NO_ENGINE_SUBSTITUTION


SET SESSION sql_mode = 'ANSI';
select @@sql_mode;


@@sql_mode


REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ANSI


SELECT name, MAX(salary), dept 
FROM `employee_gb`
GROUP BY dept;


name
MAX(salary)
dept


c
6
dept1

d
5
dept2

a
1
dept3

b
2
dept4


SET SESSION sql_mode = 'ONLY_FULL_GROUP_BY';
select @@sql_mode;


@@sql_mode


ONLY_FULL_GROUP_BY


SELECT name, MAX(salary), dept 
FROM `employee_gb`
GROUP BY dept;

'fiddle.employee_gb.name' isn't in GROUP BY