MySQL多查询设置

我试图找出如何在一个视图的大查询中放入两个或更多的select查询，但遇到了问题。最终结果应该是一行，包含两列选定字段的计数。我是否为此使用子选择

以下是前两个查询：

SELECT
  COUNT(PIN.APP_UID) AS `Type A outstanding`
FROM PMT_INSP_NORMAL PIN
  WHERE
  PIN.APP_STATUS = "To_Do"
  AND
  PIN.DATE_COMPLETED IS NULL


SELECT
  COUNT(PSN.APP_UID) AS `Type B outstanding`
FROM PMT_SIGN_NORMAL PSN
  WHERE
  PSN.APP_STATUS = "To_Do"
  AND
  PSN.DATE_COMPLETED IS NULL

试试这个：

Select 
    (SELECT COUNT(PIN.APP_UID)
FROM PMT_INSP_NORMAL PIN
WHERE PIN.APP_STATUS = "To_Do"
AND PIN.DATE_COMPLETED IS NULL) as `Type A outstanding`,


(SELECT COUNT(PSN.APP_UID)
FROM PMT_SIGN_NORMAL PSN
WHERE
PSN.APP_STATUS = "To_Do"
AND PSN.DATE_COMPLETED IS NULL) AS `Type B outstanding`

试试这个：

Select 
    (SELECT COUNT(PIN.APP_UID)
FROM PMT_INSP_NORMAL PIN
WHERE PIN.APP_STATUS = "To_Do"
AND PIN.DATE_COMPLETED IS NULL) as `Type A outstanding`,


(SELECT COUNT(PSN.APP_UID)
FROM PMT_SIGN_NORMAL PSN
WHERE
PSN.APP_STATUS = "To_Do"
AND PSN.DATE_COMPLETED IS NULL) AS `Type B outstanding`

---

是的，子查询可以做到这一点。它看起来像下面这样

SELECT (SELECT  COUNT(PIN.APP_UID) 
        FROM PMT_INSP_NORMAL PIN
         WHERE PIN.APP_STATUS = 'To_Do'  AND PIN.DATE_COMPLETED IS NULL
        ) AS 'Type A outstanding'
     ,
     (SELECT COUNT(PSN.APP_UID) 
        FROM PMT_SIGN_NORMAL PSN
        WHERE PSN.APP_STATUS = 'To_Do' AND PSN.DATE_COMPLETED IS NULL
) AS 'Type B outstanding'

---

是的，子查询可以做到这一点。它看起来像下面这样

SELECT (SELECT  COUNT(PIN.APP_UID) 
        FROM PMT_INSP_NORMAL PIN
         WHERE PIN.APP_STATUS = 'To_Do'  AND PIN.DATE_COMPLETED IS NULL
        ) AS 'Type A outstanding'
     ,
     (SELECT COUNT(PSN.APP_UID) 
        FROM PMT_SIGN_NORMAL PSN
        WHERE PSN.APP_STATUS = 'To_Do' AND PSN.DATE_COMPLETED IS NULL
) AS 'Type B outstanding'

---

那两张表有什么关联吗？有点关联。这两个表只共享一个公共性，即wo_id字段，但未将其设置为任何一个表的约束。这两个表是否以任何方式相关？某种程度上。两个表只共享1个公共项，即wo_id字段，但它没有设置为两个表的约束。谢谢，这非常有效。是的，我对次级选择的猜测有点遥远。谢谢，这非常有效。是的，我对再选举结果的猜测有点遥远。