GREATEST(n1,n2,n3,..........)

GREATEST()函数返回在该组输入参数(N1，N2，N3，等等)的最大值。 下面的示例使用GREATEST()函数从一组数字值返回最大值：

SQL>SELECT GREATEST(3,5,1,8,33,99,34,55,67,43);
+---------------------------------------------------------+
| GREATEST(3,5,1,8,33,99,34,55,67,43)                     |
+---------------------------------------------------------+
| 99                                                      |
+---------------------------------------------------------+
1 row in set (0.00 sec)