如果范围 SQL 之间缺少任何日期，则在查询结果中添加一行

Question

我是 SQL 新手，如果日期范围之间缺少任何日期，我想在查询结果中添加一行。

这是我的查询

SELECT CHECKINOUT.USERID, USERINFO.USERID,
        CAST(CHECKTIME AS DATE) DATE,
        MAX(CAST(CHECKTIME AS TIME)) as MAX_TIME,
        MIN(CAST(CHECKTIME AS TIME)) as MIN_TIME
        FROM CHECKINOUT
        LEFT JOIN USERINFO
        ON CHECKINOUT.USERID = USERINFO.USERID
        WHERE CHECKTIME BETWEEN '2020-02-01' AND '2020-02-10'
        GROUP BY CHECKINOUT.USERID,CAST(CHECKTIME AS DATE), USERINFO.USERID, USERINFO.NAME
         ORDER by CAST(CHECKTIME AS DATE), USERINFO.NAME ASC

此查询的输出

USERID  USERID  DATE    MAX_TIME    MIN_TIME
59  59  2/3/2020    4:11:48 PM  8:47:02 AM
59  59  2/4/2020    6:22:38 PM  8:45:50 AM
59  59  2/6/2020    2:33:43 PM  1:57:55 PM
59  59  2/7/2020    4:29:40 PM  8:39:38 AM
60  60  2/3/2020    4:11:48 PM  8:47:02 AM
60  60  2/4/2020    6:22:38 PM  8:45:50 AM
60  60  2/6/2020    2:33:43 PM  1:57:55 PM
60  60  2/7/2020    4:29:40 PM  8:39:38 AM
61  61  2/3/2020    4:11:48 PM  8:47:02 AM
61  61  2/4/2020    6:22:38 PM  8:45:50 AM
61  61  2/6/2020    2:33:43 PM  1:57:55 PM
61  61  2/7/2020    4:29:40 PM  8:39:38 AM

我的预期输出

    USERID  USERID  DATE    MAX_TIME    MIN_TIME
59  59  2/1/2020    NULL    NULL
59  59  2/2/2020    NULL    NULL
59  59  2/3/2020    4:11:48 PM  8:47:02 AM
59  59  2/4/2020    6:22:38 PM  8:45:50 AM
59  59  2/6/2020    2:33:43 PM  1:57:55 PM
59  59  2/7/2020    4:29:40 PM  8:39:38 AM
59  59  2/8/2020    NULL    NULL
59  59  2/9/2020    NULL    NULL
59  59  2/10/2020   NULL    NULL
60  60  2/1/2020    NULL    NULL
60  60  2/2/2020    NULL    NULL
60  60  2/3/2020    4:11:48 PM  8:47:02 AM
60  60  2/4/2020    6:22:38 PM  8:45:50 AM
60  60  2/6/2020    2:33:43 PM  1:57:55 PM
60  60  2/7/2020    4:29:40 PM  8:39:38 AM
60  60  2/8/2020    NULL    NULL
60  60  2/9/2020    NULL    NULL
60  60  2/10/2020   NULL    NULL
61  61  2/1/2020    NULL    NULL
61  61  2/2/2020    NULL    NULL
61  61  2/3/2020    4:11:48 PM  8:47:02 AM
61  61  2/4/2020    6:22:38 PM  8:45:50 AM
61  61  2/6/2020    2:33:43 PM  1:57:55 PM
61  61  2/7/2020    4:29:40 PM  8:39:38 AM
61  61  2/8/2020    NULL    NULL
61  61  2/9/2020    NULL    NULL
61  61  2/10/2020   NULL    NULL

谁能帮帮我？

Answer 1

Mysql 本身不能为不存在的数据返回行，您必须自己解决它，使其创建那些空行。

我有一个类似的question，你可以参考this answer来实现你想要的。

TLDR

您基本上使用具有足够行数的表来提供所需的空行数量（我上面链接的答案使用information_schema.columns）结合变量生成具有递增值的行（m,...,n），然后您可以使用这些行和这些值来生成您需要的缺失数据，例如您的用例的日期，最后将这些默认值行与您的真实数据行连接起来。

Answer 2

您需要生成日期列表。您可以通过多种方式做到这一点：

• 明确。
• 使用数字/计数/日历表。
• 使用递归 CTE。

然后使用CROSS JOIN 生成您想要的行。最后是 LEFT JOIN 来引入您已经计算过的数据。

这是一个例子：

WITH uc AS (
      SELECT c.USERID, CAST(CHECKTIME AS DATE) as DATE,
             MAX(CAST(CHECKTIME AS TIME)) as MAX_TIME,
             MIN(CAST(CHECKTIME AS TIME)) as MIN_TIME
      FROM CHECKINOUT c LEFT JOIN
           USERINFO u 
           ON i.USERID = u.USERID
      WHERE c.CHECKTIME BETWEEN '2020-02-01' AND '2020-02-10'
      GROUP BY c.USERID, CAST(CHECKTIME AS DATE), u.USERID, u.NAME
     )
SELECT u.USERID, d.dte, uc.min_time, uc.max_time
FROM (SELECT DISTINCT USERID FROM uc) u CROSS JOIN
     (SELECT CAST('2020-02-01' as DATE) as dte UNION ALL
      SELECT CAST('2020-02-02' as DATE) as dte UNION ALL
      . . .
      SELECT CAST('2020-02-10' as DATE) as dte UNION ALL
     ) d LEFT JOIN
     cu
     ON cu.USERID = u.USERID AND cu.DATE = d.dte
ORDER by d.dte, NAME ASC