mysql - 如何将我的结果命名为其他名称

Question

我在 MYSQL DB 中有这样的查询

SELECT date_format( doj, '%d/%m/%Y' ) AS week ,COUNT(user_id) FROm user_tb 
WHERE doj between '2012-01-01' AND '2012-01-31' group BY WEEK(doj)

Result

week    COUNT(user_id)
06/01/2012  3
17/01/2012  2
25/01/2012  3
29/01/2012  1

我怎么能这样命名

week    COUNT(user_id)
week1   3
week2   2
week3   3
week4   1

Answer 1

如果您想从 1 开始对周数进行编号，请执行以下操作：

SELECT concat('week', @row := @row + 1) AS week, COUNT(user_id)
from user_tb, (select @row := 0) r
WHERE doj between '2012-01-01' AND '2012-01-31' 
group BY WEEK(doj)

编辑

如果您想要一年中的周数，请执行以下操作：

SELECT concat('week', week(doj)) AS week, COUNT(user_id)
from user_tb, (select @row := 0) r
WHERE doj between '2012-01-01' AND '2012-01-31' 
group BY WEEK(doj)

Answer 2

搜索WEEK()at mysql 站点。

Answer 3

week()使用您在 group 语句中使用的相同功能。

SELECT CONCAT("week", WEEK(doj)) AS week, COUNT(user_id) 
FROM user_tb 
WHERE doj between '2012-01-01' AND '2012-01-31' 
GROUP BY WEEK(doj)

Answer 4

我认为最有效的方法是使用rownum（行号）并将其与“周”连接（不要忘记按周排序，以便行号与周号匹配）。

week 函数将返回一年中的星期数，我认为这不是您要寻找的。