Question

我已经对此进行了多次搜索，但遗憾的是由于我的查询类型，它总是给我PHP答案。

我将恢复代码来生成脚本，但我想的更多，我知道必须在单个查询中以更简单的方式执行它会更快。

我的代码：

SELECT DISTINCT
se.mailingID AS "mailingID",
(
    SELECT
        SUM(l.averageReadTime) 
    FROM
        eventlog AS l
    INNER JOIN sends as s ON l.mailingIDKey=s.id
    WHERE
        s.TFPIDSanitised=se.TFPIDSanitised
        AND
        l.averagerEadtIme!="-1"
        AND
        l.averageReadTime!="(none)"
) AS "Total",
(
    SELECT
        SUM(l.averageReadTime)
   FROM
        eventlog AS l
    INNER JOIN recipients AS r ON l.recipientKey=r.id
    INNER JOIN devices AS d ON r.commonDeviceKey=d.id
    INNER JOIN sends AS s ON l.mailingIDKey=s.id
    WHERE 
        d.name="AOL Mail"
        AND
        s.mailingID=se.mailingID
        AND
        l.averageReadTime!="-1"
        AND
        l.averageReadTime!="(none)"
) AS "AOL Mail",
...
[repeat for all email app types]
...
(
    SELECT
        SUM(l.averageReadTime)
    FROM
        eventlog AS l
    INNER JOIN recipients AS r ON l.recipientKey=r.id
    INNER JOIN devices AS d ON r.commonDeviceKey=d.id
    INNER JOIN sends AS s ON l.mailingIDKey=s.id
    WHERE
        d.name="AOL Desktop"
        AND
        s.mailingID=se.mailingID
        AND
        l.averageReadTime!="-1"
        AND
        l.averageReadTime!="(none)"
) AS "AOL Desktop"
FROM sends AS se
WHERE
    (
        se.sendDateTime BETWEEN '2018-01-01 00:00:00' AND '2018-01-15 23:59:59'
    );

正如你所看到的，它是一个查询的怪物。

我已经在考虑删除其中一个内连接（设备名称，只需在devices.id上搜索，而不需要第三次连接）。

我所追求的是在查询中执行某种循环：

所以它就像（我不知道真正的代码）

SELECT LOOP (devices)
    where device.id=recipients.commonDeviceKey
    AS device.name

对于mysql来说完全是这样的吗？我正在循环中进行循环（具有讽刺意味的是，这并没有丢失在我身上）因为mysql和循环没有提出相关的答案。

Answer 1

我会想象这样的事情会起作用。我没有你的确切架构，但这应该得到你需要的。

SELECT s.mailingID, SUM(l.averageReadTime), 'Total' as name
FROM eventlog AS l
  JOIN sends as s ON l.mailingIDKey=s.id
 WHERE
  l.averagerEadtIme!="-1"
  AND l.averageReadTime!="(none)"
  AND s.sendDateTime BETWEEN '2018-01-01 00:00:00' AND '2018-01-15 23:59:59'

UNION ALL

SELECT s.mailingID, SUM(l.averageReadTime), d.name 
FROM eventlog AS l
  JOIN recipients AS r ON l.recipientKey=r.id
  JOIN devices AS d ON r.commonDeviceKey=d.id
  JOIN sends AS s ON l.mailingIDKey=s.id
 WHERE 
  l.averageReadTime!="-1"
  AND l.averageReadTime!="(none)"
  AND s.sendDateTime BETWEEN '2018-01-01 00:00:00' AND '2018-01-15 23:59:59'
GROUP BY d.name
;

Answer 2

我希望找到一种更灵活的方法，最后我将在循环中使用数据库动态创建“devicesList”但下面的工作。

感谢@Napoli的帮助，虽然你可能没有向我提供你让我思考的答案，不同的解决方案（每个设备使用线性表的两步过程）。

void

mysql从另一个表值中选择值数组

2 个答案: