[英]Join 2 tables, sum and group by
應該很簡單,但是我是SQL的新手,無法正常工作:
Table 1:
ID Qty
ItemA 3
ItemB 5
ItemD 2
Table 2:
ID Qty
ItemC -1
ItemB 1.5
ItemE 2.2
我只想要一張表格,其中包含按ID匯總的數量。
像這樣:
SELECT ID, SUM(Qty) SumQty
FROM
(
SELECT ID, Qty FROM Table1
UNION ALL
SELECT ID, Qty FROM Table2
) A
GROUP BY ID
這將對“ Qty
字段求和並按ID分組:
SELECT
a.ID AS id,
(SUM(a.Qty) + SUM(b.Qty)) as qty_sum
FROM
[Table 1] as a
JOIN
[Table 2] as b ON (a.ID = b.ID)
GROUP BY 1;
您應該從此示例中摘錄的關鍵部分是:
JOIN
這就是您如何將兩個表連接起來。 注意,通過“ ON”確保兩個表中的ID都匹配(a.ID = b.ID) SUM
函數可得到總計。 GROUP BY
分組... 與@patsweet相似,但是使用INNER JOIN並且格式更易於閱讀
SELECT SUM(t1.Qty + t1.Qty) AS TotalQty ,
t1.ID
FROM [Table 1] t1
INNER JOIN [Table 2] t2 WITH (NOLOCK) ON t2.ID = t1.ID
GROUP BY t1.ID
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