Question

我有一些复杂的连接语句，想要让它变得更容易。（或者保持它，但要正常工作:)）

CREATE TABLE #Temp1
(
    ID      INT IDENTITY,
    Name1   VARCHAR(100),
    Value1  INT
)


CREATE TABLE #Temp2
(
    ID      INT IDENTITY,
    Name2   VARCHAR(100),
    Value2  INT,
    Value1  INT
)


INSERT INTO #Temp1
SELECT 'Nm_1', 111 UNION ALL
SELECT 'Nm_2', 222 


INSERT INTO #Temp2(Name2, Value2)
SELECT 'Nm_3', 333 UNION ALL
SELECT 'Nm_4', 444 UNION ALL 
SELECT 'Nm_5', 555 UNION ALL
SELECT 'Nm_6', 666 UNION ALL
SELECT 'Nm_7', 777 UNION ALL
SELECT 'Nm_8', 888 UNION ALL
SELECT 'Nm_9', 999 UNION ALL
SELECT 'Nm_4', 444 UNION ALL 
SELECT 'Nm_5', 555 UNION ALL
SELECT 'Nm_6', 666 UNION ALL
SELECT 'Nm_7', 777 UNION ALL
SELECT 'Nm_8', 888 UNION ALL
SELECT 'Nm_9', 999 UNION ALL
SELECT 'Nm_10',100 UNION ALL
SELECT 'Nm_11',110

这是两张桌子。普通的第一个表，可以有任意数量的行。第二个取决于第一个。我解释如何。＃Temp2表中的第一行是静态的，从2到7的行重复与＃Temp1中的计数一样多，最后3行也是静态的。

在我的考试中，我在＃Temp1中有两行，所以

SELECT 'Nm_4', 444 UNION ALL 
SELECT 'Nm_5', 555 UNION ALL
SELECT 'Nm_6', 666 UNION ALL
SELECT 'Nm_7', 777 UNION ALL
SELECT 'Nm_8', 888 UNION ALL
SELECT 'Nm_9', 999 UNION ALL

是两次，如果我有3则会有6 * 3行。

现在我想以这种方式在＃Temp2表中更新Value1列。

从＃Temp1中选择Value1，其中ID = 1

此值将写入＃Temp2表，其中ID＆gt; = 2且ID <= 7

从＃Temp1中选择Value1，其中ID = 2

应位于＃Temp2表中，其中ID＆gt; = 8且ID <= 13。

我尝试写这样的连接

UPDATE #Temp2
SET Value1 = a.Value1
FROM #Temp1 AS a
INNER JOIN #Temp2 AS b
    ON 2*a.ID - b.ID IN (-(2*a.ID-1)-(a.ID-2),
                         -(2*a.ID-1)-(a.ID-1),
                         -(2*a.ID-1)-(a.ID-0),
                         -(2*a.ID-1)-(a.ID+1),
                         -(2*a.ID-1)-(a.ID+2),
                         -(2*a.ID-1)-(a.ID+3))

但这是错误的，如果你运行这个脚本，你可以看到。有人可以帮忙吗？

显然应该使用ID列

进行加入

Answer 1

这个简单的加入工作：

UPDATE #Temp2
SET Value1 = a.Value1
FROM #Temp1 AS a
INNER JOIN #Temp2 AS b
ON b.ID BETWEEN (a.ID*6-4) AND (a.ID*6+1)

Answer 2

您可以将子查询与CASE WHEN一起使用。您可以使用BETWEEN标记来处理您的ID。

UPDATE #Temp2
SET #Temp2.Value1 = (CASE WHEN ID BETWEEN 2 AND 7 THEN (SELECT a.Value1 FROM #Temp1 a WHERE a.ID = 1)
                          WHEN ID BETWEEN 8 AND 13 THEN (SELECT a.Value1 FROM #Temp1 a WHERE a.ID = 2)
                     END)
WHERE #Temp2.ID BETWEEN 2 AND 13

Answer 3

你可以试试这个可以解决你的问题：

DECLARE @Counter int = 0,
        @Rows int

Set @Rows = (Select count(*) from #Temp1)

While (@Counter < @Rows)
Begin

    Update #Temp2
    Set Value1 = (Select Value1 from #Temp1 where ID = @Counter + 1)
    Where ID between 2 + (@Counter * 6) and 7 + (@Counter * 6)
    Set @Counter = @Counter + 1

End

在sql中进行复杂的更新/连接

3 个答案: