MySQL中MIN()函數的應用教程。本站提示廣大學習愛好者:(MySQL中MIN()函數的應用教程)文章只能為提供參考,不一定能成為您想要的結果。以下是MySQL中MIN()函數的應用教程正文
MySQL的MIN函數是用來找出一個記載集最小值的記載。
要懂得MIN函數斟酌的EMPLOYEE_TBL表具有以下記載:
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)
如今假定下面的表的基本上想要取daily_typing_pages的最小值,那末可以如許做,簡略地應用上面的敕令:
mysql> SELECT MIN(daily_typing_pages) -> FROM employee_tbl; +-------------------------+ | MIN(daily_typing_pages) | +-------------------------+ | 100 | +-------------------------+ 1 row in set (0.00 sec)
可以找到一切記載的最小值按名字應用GROUP BY子句以下:
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)
您可使用MIN函數和MAX函數一路,查找最小值。嘗嘗上面的例子:
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)