我创建了一个包含一个常规表和两个派生表（子查询）的选择查询。派生表都通过左连接与常规表连接。常规表包含超过 7000 行，但查询输出约为 3000 行。它必须等于常规表中的记录数。我的错误是什么？
SELECT T0.[ItemCode],
T0.[ItemName],
CASE T0.[PrcrmntMtd] WHEN 'B' THEN 'Inkoop' ELSE 'Productie' END AS Verwervingsmethode,
T0.[OnHand] AS Voorraad_excl_grondstof_reeds_verwerkt,
T1.[Reeds_geproduceerd] AS Grondstof_reeds_verwerkt,
CASE WHEN T1.[Reeds_geproduceerd] IS NULL
THEN T0.[OnHand]
ELSE T0.[OnHand]-T1.[Reeds_geproduceerd]
END AS Voorraad_incl_grondstof_reeds_verwerkt,
T2.[Nog_te_produceren] AS Geplande_productie_halffabrikaat_eindproduct,
T1.[Nog_te_produceren] AS Gereserveerd_voor_productie_grondstof_halffabrikaat,
CASE WHEN T1.[Reeds_geproduceerd] IS NULL
THEN (T0.[OnHand]/T2.[Nog_te_produceren])*30
ELSE ((T0.[OnHand]-T1.[Reeds_geproduceerd])/T2.[Nog_te_produceren])*30
END AS Dagen_voorraad_halffabrikaat_eindproduct,
CASE WHEN T1.[Reeds_geproduceerd] IS NULL
THEN (T0.[OnHand]/T1.[Nog_te_produceren])*30
ELSE ((T0.[OnHand]-T1.[Reeds_geproduceerd])/T1.[Nog_te_produceren])*30
END AS Dagen_voorraad_grondstof_halffabrikaat
FROM OITM T0
LEFT JOIN (
SELECT T1.[ItemCode],
SUM(T0.[PlannedQty]*T1.[BaseQty]) AS Geplande_productie,
CASE WHEN SUM(T0.CmpltQty) IS NULL THEN SUM(T0.[PlannedQty]*T1.[BaseQty]) ELSE SUM(T0. [CmpltQty]*T1.[BaseQty]) END AS Reeds_geproduceerd,
CASE WHEN SUM(T0.CmpltQty) IS NULL THEN SUM(T0.[PlannedQty]*T1.[BaseQty]) ELSE SUM(T0.[PlannedQty]*T1.[BaseQty])-SUM(T0.[CmpltQty]*T1.[BaseQty]) END AS Nog_te_produceren
FROM OWOR T0
INNER JOIN WOR1 T1 ON T0.DocEntry = T1.DocEntry
WHERE T0.DueDate <= getdate()+30
AND (T0.[Status] LIKE 'p'
OR T0.[Status] LIKE 'r')
GROUP BY T1.[ItemCode]
) AS T1
ON T0.ItemCode = T1.ItemCode
LEFT JOIN (
SELECT T0.[ItemCode],
SUM(T0.[PlannedQty]) AS Geplande_productie,
SUM(T0.[CmpltQty]) AS Reeds_geproduceerd,
SUM(T0.[PlannedQty])-SUM(T0.[CmpltQty]) AS Nog_te_produceren
FROM OWOR T0
INNER JOIN WOR1 T1 ON T0.DocEntry = T1.DocEntry
WHERE T0.DueDate <= getdate()+30
AND (T0.[Status] LIKE 'p'
OR T0.[Status] LIKE 'r')
GROUP BY T0.[ItemCode]
) AS T2
ON T0.ItemCode = T2.ItemCode
我提到了所有的 where 子句。如果我把链接的页面变红了，那不是问题。
我还更改了派生表的表名和列名。现在所有表名和列名都是唯一的。
但仍然是同样的问题。当我删除 select 中的最后两个 case 语句时，我确实得到了所有输出行，但我在这些 case 语句中看不到任何问题。
SELECT T0.[ItemCode],
T0.[ItemName],
CASE T0.[PrcrmntMtd] WHEN 'B' THEN 'Inkoop' ELSE 'Productie' END AS Verwervingsmethode,
T0.[OnHand] AS Voorraad_excl_grondstof_reeds_verwerkt,
T3.[Reeds_geproduceerd_grond] AS Grondstof_reeds_verwerkt,
CASE WHEN T3.[Reeds_geproduceerd_grond] IS NULL
THEN T0.[OnHand]
ELSE T0.[OnHand]-T3.[Reeds_geproduceerd_grond]
END AS Voorraad_incl_grondstof_reeds_verwerkt,
T6.[Nog_te_produceren_eind] AS Geplande_productie_halffabrikaat_eindproduct,
T3.[Nog_te_produceren_grond] AS Gereserveerd_voor_productie_grondstof_halffabrikaat,
CASE WHEN T3.[Reeds_geproduceerd_grond] IS NULL
THEN 30*(T0.[OnHand]/T6.[Nog_te_produceren_eind])
ELSE 30*((T0.[OnHand]-T3.[Reeds_geproduceerd_grond])/T6.[Nog_te_produceren_eind])
END AS Dagen_voorraad_halffabrikaat_eindproduct,
CASE WHEN T3.[Reeds_geproduceerd_grond] IS NULL
THEN 30*(T0.[OnHand]/T3.[Nog_te_produceren_grond])
ELSE 30*((T0.[OnHand]-T3.[Reeds_geproduceerd_grond])/T3.[Nog_te_produceren_grond])
END AS Dagen_voorraad_grondstof_halffabrikaat
FROM OITM T0
LEFT JOIN (
SELECT T2.[ItemCode] AS ItemCode_grond,
SUM(T1.[PlannedQty]*T2.[BaseQty]) AS Geplande_productie_grond,
CASE WHEN SUM(T1.CmpltQty) IS NULL
THEN SUM(T1.[PlannedQty]*T2.[BaseQty])
ELSE SUM(T1.[CmpltQty]*T2.[BaseQty])
END AS Reeds_geproduceerd_grond,
CASE WHEN SUM(T1.CmpltQty) IS NULL
THEN SUM(T1.[PlannedQty]*T2.[BaseQty])
ELSE SUM(T1.[PlannedQty]*T2.[BaseQty])-SUM(T1.[CmpltQty]*T2.[BaseQty])
END AS Nog_te_produceren_grond
FROM OWOR T1
INNER JOIN WOR1 T2 ON T1.DocEntry = T2.DocEntry
WHERE T1.DueDate <= getdate()+30
AND (T1.[Status] LIKE 'p'
OR T1.[Status] LIKE 'r')
GROUP BY T2.[ItemCode]
) AS T3
ON T0.ItemCode = T3.ItemCode_grond
LEFT JOIN (
SELECT T4.[ItemCode] AS ItemCode_eind,
SUM(T4.[PlannedQty]) AS Geplande_productie_eind,
SUM(T4.[CmpltQty]) AS Reeds_geproduceerd_eind,
SUM(T4.[PlannedQty])-SUM(T4.[CmpltQty]) AS Nog_te_produceren_eind
FROM OWOR T4
INNER JOIN WOR1 T5 ON T4.DocEntry = T5.DocEntry
WHERE T4.DueDate <= getdate()+30
AND (T4.[Status] LIKE 'p'
OR T4.[Status] LIKE 'r')
GROUP BY T4.[ItemCode]
) AS T6
ON T0.ItemCode = T6.ItemCode_eind