SQL SUM 子查询

Question

反正有没有查询这样的东西？

SELECT
    SUM(
        SELECT Tbl1.Cost FROM Tbl1 WHERE Tbl1.Type = 0 +
        SELECT Tbl2.Cost FROM Tbl2 WHERE Tbl2.Type = 0 +
        SELECT Tbl3.Cost FROM Tbl3 WHERE Tbl3.Type = 0
    ) AS EstimatedCost
FROM Tbl1 <JOIN> Tbl2 <JOIN> Tbl3
GROUP BY Tbl1.id,Tbl2.id,Tbl3.id,Tbl1.num,Tbl2.num,Tbl3.num

编辑

我有当前的 sql 查询

SELECT 
    COALESCE (vJoboutsEst.ddTask_id, vMaterialsEst.ddTask_id, vLaborsEst.ddTask_id) AS ddTask_id,
    COALESCE (vJoboutsEst.dd_id, vMaterialsEst.dd_id, vLaborsEst.dd_id) AS dd_id,
    SUM(
      CASE WHEN vJoboutsEst.jo_cost IS NULL THEN 0 ELSE vJoboutsEst.jo_cost END
      + 
      CASE WHEN vMaterialsEst.item_amt IS NULL THEN 0 ELSE vMaterialsEst.item_amt END
      + 
      CASE WHEN vLaborsEst.labor_amt IS NULL THEN 0 ELSE vLaborsEst.labor_amt END
    ) AS EstimateCost
FROM 
vDryDock,
(
    SELECT vJoboutsEst.ddTask_id, vJoboutsEst.dd_id,SUM(vJoboutsEst.jo_cost) as jo_cost
    FROM vJoboutsEst WHERE vJoboutsEst.jo_type = 0 GROUP BY vJoboutsEst.ddTask_id, vJoboutsEst.dd_id
) vJoboutsEst 
FULL OUTER JOIN (
    SELECT vMaterialsEst.ddTask_id, vMaterialsEst.dd_id,SUM(vMaterialsEst.item_amt) as item_amt
    FROM vMaterialsEst WHERE vMaterialsEst.material_type = 0 GROUP BY vMaterialsEst.ddTask_id, vMaterialsEst.dd_id
) vMaterialsEst ON vJoboutsEst.ddTask_id = vMaterialsEst.ddTask_id
FULL OUTER JOIN (
    SELECT vLaborsEst.ddTask_id, vLaborsEst.dd_id,SUM(vLaborsEst.labor_amt) as labor_amt
    FROM vLaborsEst WHERE vLaborsEst.labor_type = 0 GROUP BY vLaborsEst.ddTask_id, vLaborsEst.dd_id
) vLaborsEst ON ISNULL(vJoboutsEst.ddTask_id, vMaterialsEst.ddTask_id) = vLaborsEst.ddTask_id
GROUP BY
    vJoboutsEst.ddTask_id, vMaterialsEst.ddTask_id, vLaborsEst.ddTask_id,
    vJoboutsEst.dd_id, vMaterialsEst.dd_id, vLaborsEst.dd_id

这是我在数据库上的示例数据：

看这里

我还附上了查询输出，但我想要的输出是这样的

ddTask_id    dd_id    EstimateCost
31           15       40
32           16       40

Answer 1

尝试使用此查询：

 SELECT
        SUM(
            (SELECT sum(Tbl1.Cost) FROM Tbl1 WHERE Tbl1.Type = 0) +
            (SELECT sum(Tbl2.Cost) FROM Tbl2 WHERE Tbl2.Type = 0) +
            (SELECT sum(Tbl3.Cost) FROM Tbl3 WHERE Tbl3.Type = 0)
        ) AS EstimatedCost
    FROM Tbl1 <JOIN> Tbl2 <JOIN> Tbl3
    GROUP BY Tbl1.id,Tbl2.id,Tbl3.id,Tbl1.num,Tbl2.num,Tbl3.num

Answer 2

查看您的示例数据（它没有任何 dd_id 列！），您可以通过使用 union all 语句而不是完全外连接来做到这一点。 试试下面的查询：

SELECT 
    ddTask_id,
    dd_id,
    SUM(EstimatedCost) AS EstimateCost
FROM 
(
    SELECT vJoboutsEst.ddTask_id, vJoboutsEst.dd_id,SUM(vJoboutsEst.jo_cost) as EstimatedCost
    FROM vJoboutsEst WHERE vJoboutsEst.jo_type = 0 GROUP BY vJoboutsEst.ddTask_id, vJoboutsEst.dd_id

    UNION ALL

    SELECT vMaterialsEst.ddTask_id, vMaterialsEst.dd_id,SUM(vMaterialsEst.item_amt) as EstimatedCost
    FROM vMaterialsEst WHERE vMaterialsEst.material_type = 0 GROUP BY vMaterialsEst.ddTask_id, vMaterialsEst.dd_id

    UNION ALL


    SELECT vLaborsEst.ddTask_id, vLaborsEst.dd_id,SUM(vLaborsEst.labor_amt) as EstimatedCost
    FROM vLaborsEst WHERE vLaborsEst.labor_type = 0 GROUP BY vLaborsEst.ddTask_id, vLaborsEst.dd_id
)aa
GROUP BY
    ddTask_id, dd_id