使用动态变量的SQL Server Select语句

Question

好的，在下面的语句中，我尝试将第一个选择的pi.planinfoid用作第一个字段，并使其成为动态变量，以代替在两个select语句中用作附加字段的1736 。

我还需要它仍然返回由两个select语句生成的两个字段，即使该值为0或null。

如果您能解决这个问题，我先不知所措。

SELECT  pi.planinfoid,
        pi.description,
        count(DISTINCT p.planid) AS total,
        sum(dm.debitamount) AS Num,
        pi.minperiod,
        (
            SELECT count(p.planid)
            FROM plans p,
                    planinfo pi
            WHERE pi.planinfoid = p.planinfoid
                    AND pi.planinfoid = '1736'
                    AND p.closed = 0
        ) AS opened,
        (
            SELECT count(p.planid)
            FROM plans p,
                    planinfo pi
            WHERE pi.planinfoid = p.planinfoid
                    AND pi.planinfoid = '1736'
                    AND p.closed = 1
        ) AS closedd
FROM    planinfo pi, plans p, debitmovements dm
WHERE   pi.price > 0
        AND p.planinfoid = pi.planinfoid
        AND dm.planid = p.planid
        AND p.servicestart BETWEEN '2012-01-01' AND '2013-01-01'
GROUP BY    pi.description,
            pi.minperiod,
            pi.planinfoid
ORDER BY total DESC

那已经过去了，但无论如何，打开和关闭似乎都与总数无关，

planid  plan descrip   min      TOTAL   PRICE   OPEN    CLOSE
1736    Additional IP   1   146 1926    101 545

从技术上讲，如果在那个时间段内售出的总数是146，则您将无法打开101，关闭545，也许它没有拉动的数量仍然只打开和关闭在那个时间段内。 146个空位的uniqe字段将是p.planid，或者每个基本上都有一个唯一的p.planid，尽管如此，到目前为止还是不错的。

Answer 1

尝试这个：

SELECT
  pi.planinfoid, 
  pi.description, 
  pi.minperiod,
  count(DISTINCT p.planid) AS total,
  sum(dm.debitamount) AS Num, 
  SUM(CASE WHEN p.closed = 0 THEN 1 ELSE 0 END) AS opened,
  SUM(CASE WHEN p.closed = 1 THEN 1 ELSE 0 END) AS closedd
FROM planinfo pi  
INNER JOIN plans           p ON p.planinfoid = pi.planinfoid
INNER JOIN debitmovements dm ON dm.planid    = p.planid 
WHERE pi.price > 0
  AND p.servicestart BETWEEN '2012-01-01' 
                         AND '2013-01-01'
GROUP BY pi.description,
         pi.minperiod,
         pi.planinfoid 
ORDER BY total DESC;

我在这里所做的是：

• 我使用了隐式JOIN语法，即ANSI-92 SQL Standard，而不是旧的语​​法。
• 用两个CASE表达式替换了两个相关的COUNT()子查询。
• 我将pi.planinfoid = 1736移到WHERE子句中，可以将其置于CASE表达式条件中。
• 您将需要通过planinfoid您正在寻找替代@value 。

Answer 2

对于我来说，很难说是否应将分组条件应用于计数。 要使计数明确，可以使用子查询：

SELECT  pi.planinfoid,
        pi.description,
        count(DISTINCT p.planid) AS total,
        sum(dm.debitamount) AS Num,
        pi.minperiod,
        max(opened) as opened,
        max(closed) as closed
FROM    planinfo pi join
        plans p
        on p.planinfoid = pi.planinfoid join
        debitmovements dm
        on dm.planid = p.planid left outer join
        (select planinfoid, SUM(1-p.closed) as opened, SUM(p.closed) as closed
         from planinfo pi join
              plans p
              on pi.planinfoid = p.planinfoid
         group by planinfoid
        ) psum
        on psum.planinfoid = psum.planinfoid
WHERE   pi.price > 0 AND
        p.servicestart BETWEEN '2012-01-01' AND '2013-01-01'
GROUP BY    pi.description,
            pi.minperiod,
            pi.planinfoid
ORDER BY total DESC

但是，在问题的上下文中，您可以通过给内部子查询提供不同的别名来执行所需的操作：

    (
        SELECT count(p2.planid)
        FROM plans p2 join
             planinfo pi2
             on pi2.planinfoid = p2.planinfoid
        WHERE
                pi2.planinfoid = pi.planinfoid
                AND p2.closed = 0
    ) AS opened,