greatest()是MySQL的一个Math函数。此函数用于从列表中获取最大数。
语法
select greatest(exp1, exp2, exp3....); 参数:
Exp1, exp2, exp3.... expn:求最大数的表达式。
返回
此函数返回列表中的最大数字。
示例 1
Select greatest(4,5,3,9,0); 输出:
mysql> Select greatest(4,5,3,9,0);
+---------------------+
| greatest(4,5,3,9,0) |
+---------------------+
| 9 |
+---------------------+
1 row in set (0.01 sec)
+---------------------+
| greatest(4,5,3,9,0) |
+---------------------+
| 9 |
+---------------------+
1 row in set (0.01 sec)
示例 2
Select greatest('j','a','v','a'); 输出:
mysql> Select greatest('j','a','v','a');
+---------------------------+
| greatest('j','a','v','a') |
+---------------------------+
| v |
+---------------------------+
1 row in set (0.00 sec)
+---------------------------+
| greatest('j','a','v','a') |
+---------------------------+
| v |
+---------------------------+
1 row in set (0.00 sec)
示例 3
Select greatest('yxjc123','string_finction','math_function','date_function',""); 输出:
mysql> Select greatest('yxjc123','string_finction','math_function','date_function',"");
+--------------------------------------------------------------------------+
| greatest('yxjc123','string_finction','math_function','date_function',"") |
+--------------------------------------------------------------------------+
| yxjc123 |
+--------------------------------------------------------------------------+
1 row in set (0.00 sec)
+--------------------------------------------------------------------------+
| greatest('yxjc123','string_finction','math_function','date_function',"") |
+--------------------------------------------------------------------------+
| yxjc123 |
+--------------------------------------------------------------------------+
1 row in set (0.00 sec)