In this post, I am giving you a full demonstration on finding max value for each group of records in MySQL.

Today morning, I was working on one report and requirement is to find max value records for each particular group of data.

I know, You guys are thinking that this is a very simple solution using MAX() and GROUP BY clause.
But many of database developers have always questioned about: Why we cannot add any other columns in SELECT list which are not part of aggregation or the GROUP BY clause?

Below is a one solution, you can find MAX record without using GROUP BY clause and you can also add other columns in the SELECT list.

First, Create a table with sample data:

CREATE TABLE tbl_EmployeeDetails
(
	EmpID INTEGER PRIMARY KEY 
    ,EmpName VARCHAR(50)
    ,EmpSalary BIGINT
    ,DepartmentName VARCHAR(50)
);

INSERT INTO tbl_EmployeeDetails
VALUES 
(1,'Anvesh',80000,'Sales')
,(2,'Neevan',90000,'Sales')
,(3,'Jenny',50000,'Production')
,(4,'Roy',60000,'Production')
,(5,'Martin',30000,'Research')
,(6,'Mahi',85000,'Research')
,(7,'Kruti',45000,'Research')
,(8,'Manish',75000,'Research');

Find max salary values for each department:

SELECT ED1.*
FROM tbl_EmployeeDetails ED1                   
LEFT JOIN tbl_EmployeeDetails ED2       
  ON ED1.DepartmentName = ED2.DepartmentName 
  AND ED1.EmpSalary < ED2.EmpSalary
WHERE ED2.EmpSalary IS NULL

The Result: