sql - 不同表中的多个查询

Question

(也发布了 here 。)

所以我有两个表，一个是invalid表，另一个是valid表。

有效表:

id
status
date

无效表:

id
status
date

我必须使用此输出生成报告:

date       on-time  late  total  valid  invalid1  invalid2  total  rate
---------  -------  ----  -----  -----  --------  --------  -----  ----
9/10/2011  4        10    14     3      3         3         6   

• date:2张表的公共(public)字段，分组依据的字段，当天有多少条记录
• on-time:有效表上所有id的计数
• late: 无效表中所有记录(id)的计数
• total:准时和迟到的总和
• valid:有效表中状态为“valid”的id的个数
• invalid1:无效表中状态为“invalid1”的 id 计数
• invalid2:无效表中状态为“invalid2”的 id 计数
• total:有效、无效1、无效2的总数
• rate:总数的平均值

它基本上是对不同表的多个查询。我怎样才能实现它？

Answer 1

是这样的吗？

SELECT
    *,
    (result.total + result._total) / 2 AS rate
FROM (
    SELECT
        date,
        SUM(CASE WHEN data.valid = 1 THEN 1 ELSE 0 END) AS ontime,
        SUM(CASE WHEN data.valid = 0 THEN 1 ELSE 0 END) AS late,
        COUNT(*) AS total,
        SUM(CASE WHEN data.valid = 1 AND data.status = 'valid' THEN 1 ELSE 0 END) AS valid,
        SUM(CASE WHEN data.valid = 0 AND data.status = 'invalid1' THEN 1 ELSE 0 END) AS invalid1,
        SUM(CASE WHEN data.valid = 0 AND data.status = 'invalid2' THEN 1 ELSE 0 END) AS invalid2,
        SUM(CASE WHEN data.status IN ('valid', 'invalid', 'invalid2') THEN 1 ELSE 0 END) AS _total

    FROM (
        SELECT
            date,
            status,
            valid = 1
        FROM
            Valid
        UNION ALL
        SELECT
            date,
            status,
            valid = 0
        FROM
            InValid ) AS data
    GROUP BY
        date) AS result