MySQL中MIN()函数的使用教程

MySQL的MIN函数是用来找出一个记录集最小值的记录。

要了解MIN函数考虑的EMPLOYEE_TBL表具有以下记录:

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mysql> SELECT * FROM employee_tbl;
+ ------+------+------------+--------------------+
| id  | name | work_date | daily_typing_pages |
+ ------+------+------------+--------------------+
|  1 | John | 2007-01-24 |        250 |
|  2 | Ram | 2007-05-27 |        220 |
|  3 | Jack | 2007-05-06 |        170 |
|  3 | Jack | 2007-04-06 |        100 |
|  4 | Jill | 2007-04-06 |        220 |
|  5 | Zara | 2007-06-06 |        300 |
|  5 | Zara | 2007-02-06 |        350 |
+ ------+------+------------+--------------------+
7 rows in set (0.00 sec)

现在假设上面的表的基础上想要取daily_typing_pages的最小值,那么可以这样做,简单地使用下面的命令:

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mysql> SELECT MIN (daily_typing_pages)
   -> FROM employee_tbl;
+ -------------------------+
| MIN (daily_typing_pages) |
+ -------------------------+
|           100 |
+ -------------------------+
1 row in set (0.00 sec)

可以找到所有记录的最小值按名字使用GROUP BY子句如下:

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mysql> id, name , work_date, MIN (daily_typing_pages)
   -> FROM employee_tbl GROUP BY name ;
+ ------+------+------------+-------------------------+
| id  | name | work_date | MIN (daily_typing_pages) |
+ ------+------+------------+-------------------------+
|  3 | Jack | 2007-05-06 |           100 |
|  4 | Jill | 2007-04-06 |           220 |
|  1 | John | 2007-01-24 |           250 |
|  2 | Ram | 2007-05-27 |           220 |
|  5 | Zara | 2007-06-06 |           300 |
+ ------+------+------------+-------------------------+
5 rows in set (0.00 sec)

您可以使用MIN函数和MAX函数一起,查找最小值。试试下面的例子:

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mysql> SELECT MIN (daily_typing_pages) least, MAX (daily_typing_pages) max
   -> FROM employee_tbl;
+ -------+------+
| least | max |
+ -------+------+
|  100 | 350 |
+ -------+------+
1 row in set (0.01 sec)

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