How to get the max of two values in MySQL?
MysqlMaxMysql Problem Overview
I tried but failed:
mysql> select max(1,0);
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '0)' at line 1
Mysql Solutions
Solution 1 - Mysql
Use GREATEST()
E.g.:
SELECT GREATEST(2,1);
Note: Whenever if any single value contains null at that time this function always returns null (Thanks to user @sanghavi7)
Solution 2 - Mysql
To get the maximum value of a column across a set of rows:
SELECT MAX(column1) FROM table; -- expect one result
To get the maximum value of a set of columns, literals, or variables for each row:
SELECT GREATEST(column1, 1, 0, @val) FROM table; -- expect many results
Solution 3 - Mysql
You can use GREATEST function with not nullable fields. If one of this values (or both) can be NULL, don't use it (result can be NULL).
select
if(
fieldA is NULL,
if(fieldB is NULL, NULL, fieldB), /* second NULL is default value */
if(fieldB is NULL, field A, GREATEST(fieldA, fieldB))
) as maxValue
You can change NULL to your preferred default value (if both values is NULL).