For example, mysql has the following data structure

At present, there is already one sql to query the maximum value in the three columns of AB C. Would you like to ask if there are any other better idea? ..

`Select id,a,b,c,(a plus ((b plus c plus abs(b-c))/2) plus abs(a-(b plus c plus abs (b-c))/2) from test;`

I learned another lesson from others this afternoon.`greatest`

Function

`select id,a,b,c,greatest(a,b,c) as max from XXX`

`mysql> set @a = 5, @b = 6, @c = 11; Query OK, 0 rows affected (0.00 sec) mysql> select if(@a > @b, if(@a > @c, @a, @c), if(@b > @c, @b, @c)) max; Plus-plus | max | Plus-plus | 11 | Plus-plus 1 row in set (0.00 sec)`