多行子查询MYSQL

Question

我需要有关此查询的帮助，我不知道该如何执行子查询，但是我想做的是以下操作：

Date ， HNO ， IDNAM ， IDFNAM ， Pre weight ， post weight ， Calculation pre weight - post weight

我得到的问题是这是如何将数据存储在权重列的表中，请参阅下面的数据库表示例数据，在权重相同列中有一行用于前置，然后有另一行用于发布

 28/04/2017,D123456,BLOGGS,Joe,HOSP HD,79.8,POST 28/04/2017,D123456,BLOGGS,Joe,HOSP HD,80.4,PRE 26/04/2017,D123456,BLOGGS,Joe,HOSP HD,79.2,POST 26/04/2017,D123456,BLOGGS,Joe,HOSP HD,80.2,PRE 21/04/2017,D123456,BLOGGS,Joe,HOSP HD,78.6,POST 21/04/2017,D123456,BLOGGS,Joe,HOSP HD,82.8,PRE 

我想达到以下结果

 28/04/2017|D123456|BLOGGS|Joe|HOSP HD|80.4 Pre|79.8 Post|calculation using alias 26/04/2017|D123456|BLOGGS|Joe|HOSP HD|80.2 Pre|79.2 Post|calculation using alias 21/04/2017|D123456|BLOGGS|Joe|HOSP HD|82.8 Pre|78.6 Post|calculation 

 SELECT DATE_FORMAT(D1.HRDATE, '%d/%m/%Y') AS Date, IDHNO, IDNAM, IDFNAM,IDSTS,
(SELECT HRWGT FROM p_dialysis D2 WHERE D2.oid = D1.oid AND HRPrePost LIKE 'pre' AND HRWGT is not null) AS Pre,
(SELECT HRWGT FROM p_dialysis D3 WHERE D3.oid = D1.oid AND HRPrePost LIKE 'post' AND HRWGT is not null) AS Post,
(SELECT (SELECT Pre) - (SELECT Post)) AS Total FROM p_dialysis D1
    LEFT JOIN p_person ON D1.fk_oid = p_person.oid WHERE D1.HRDATE BETWEEN STR_TO_DATE('01/04/2017', '%d/%m/%Y') AND STR_TO_DATE('30/04/2017', '%d/%m/%Y') AND IDHNO LIKE 'D000000%' AND D1.HRWGT > 0

上面的代码产生了这个结果

 28/04/2017 D123456 BLOGGS Joe HOSP HD NULL 79.8 28/04/2017 D123456 BLOGGS Joe HOSP HD 80.4 NULL 26/04/2017 D123456 BLOGGS Joe HOSP HD NULL 79.2 26/04/2017 D123456 BLOGGS Joe HOSP HD 80.2 NULL 21/04/2017 D123456 BLOGGS Joe HOSP HD NULL 78.6 21/04/2017 D123456 BLOGGS Joe HOSP HD 82.8 NULL 

Answer 1

我对您的总表模式有些困惑，但是要获得结果，您可以将表本身作为子查询进行联接以获得结果

SELECT DATE_FORMAT(pre.HRDATE, '%d/%m/%Y') AS Date, pre.IDHNO, pre.IDNAM, pre.IDFNAM, pre.IDSTS,  CONCAT(pre.HRPrePost, ' ' ,pre.HRWGT), CONCAT(pst.HRPrePost,' ' ,pst.HRWGT)
FROM your_table pre
    INNER JOIN(
    SELECT DATE_FORMAT(HRDATE, '%d/%m/%Y') AS Date, IDHNO, IDNAM, IDFNAM, IDSTS, HRPrePost, HRWGT
    FROM your_table 
        WHERE HRPrePost = 'POST'
) pst
ON pst.`Date` = DATE_FORMAT(pre.HRDATE, '%d/%m/%Y') AND pre.IDHNO = pst.IDHNO

WHERE pre.HRPrePost = 'PRE'