Sql 将两个查询连接到一个表并减去值

我需要将这两个输出值（

Add_sum

和

减_sum

）放到一个表中，然后减去它们（

Add_sum-减_sum

）并显示此值

我尝试了许多其他的选择，子查询等，但无法让它工作

问题1：

SELECT        I.ItemCode, COUNT(H.TransactionTypeID) AS ADD_Sum
FROM            inMoveHd AS H INNER JOIN
                         inMoveLn AS L ON L.InvMoveID = H.InvMoveID INNER JOIN
                         inItem AS I ON I.ItemID = L.ItemID INNER JOIN
                         inTransactionType AS T ON H.TransactionTypeID = T.TransactionTypeID
WHERE        (T.TransactionSign = 1)
GROUP BY I.ItemCode

问题2：

SELECT        I.ItemCode, COUNT(H.TransactionTypeID) AS Minus_Sum
FROM            inMoveHd AS H INNER JOIN
                         inMoveLn AS L ON L.InvMoveID = H.InvMoveID INNER JOIN
                         inItem AS I ON I.ItemID = L.ItemID INNER JOIN
                         inTransactionType AS T ON H.TransactionTypeID = T.TransactionTypeID
WHERE        (T.TransactionSign = -1)
GROUP BY I.ItemCode

---

使用

case

表达式进行条件聚合：

SELECT        
    I.ItemCode, 
    SUM(CASE WHEN T.TransactionSign = 1  THEN 1 ELSE 0 END) AS Add_Sum,
    SUM(CASE WHEN T.TransactionSign = -1 THEN 1 ELSE 0 END) AS Minus_Sum,
    SUM(T.TransactionSign) difference
FROM 
    inMoveHd AS H INNER JOIN
    inMoveLn AS L ON L.InvMoveID = H.InvMoveID INNER JOIN
    inItem AS I ON I.ItemID = L.ItemID INNER JOIN
    inTransactionType AS T ON H.TransactionTypeID = T.TransactionTypeID
WHERE  T.TransactionSign IN (-1, 1)
GROUP BY I.ItemCode

---

我认为您正在寻找条件聚合：

SELECT        
    I.ItemCode, 
    SUM(CASE WHEN T.TransactionSign = 1  THEN 1 ELSE 0 END) AS Add_Sum,
    SUM(CASE WHEN T.TransactionSign = -1 THEN 1 ELSE 0 END) AS Minus_Sum,
    SUM(T.TransactionSign) difference
FROM 
    inMoveHd AS H INNER JOIN
    inMoveLn AS L ON L.InvMoveID = H.InvMoveID INNER JOIN
    inItem AS I ON I.ItemID = L.ItemID INNER JOIN
    inTransactionType AS T ON H.TransactionTypeID = T.TransactionTypeID
WHERE  T.TransactionSign IN (-1, 1)
GROUP BY I.ItemCode

---

帮助你要容易些，我希望会更好