Question

我的桌子如下所示

col1    california    florida     hawaii     date
=================================================
a1      32            86            23         Jan
a2      67            63            8990       Jan
a3      86            453           6          Jan
b1      54            876           7868       Jan
b2      6             786           75         Jan
b3      988           56            876        Jan
c1      1             2344          6          Jan
c2      876           57            986        Jan
c3      12            67            76         Jan
a1      0             0             0          feb
a2      0             0             0          feb
a3      0             0             0          feb
b1      0             0             0          feb
b2      0             0             0          feb
b3      0             0             0          feb
c1      1             3             67         feb
c2      9             7             32         feb
c3      12            67            76         feb
a1      0             0             0          mar
a2      0             0             0          mar
a3      0             0             0          mar
b1      0             0             0          mar
b2      0             0             0          mar
b3      0             0             0          mar
c1      66            2             9          mar
c2      32            7             1          mar
c3      12            67            76         mar

现在我想为每个状态更新每个a1 = b1 = c1和a2 = b2 = c2和a3 = b3 = c3（如果它们是空的）

我想要每月给出如下所示的逻辑

if(a1==0) then a1=c1
if(a2==0) then a2=c2
if(a3==0) then a3=c3

if(b1==0) then b1=c1
if(b2==0) then b2=c2
if(b3==0) then b3=c3

如何为此编写查询..？

我需要的输出是

col1    california    florida     hawaii     date
=================================================
a1      32            86            23         Jan
a2      67            63            8990       Jan
a3      86            453           6          Jan
b1      54            876           7868       Jan
b2      6             786           75         Jan
b3      988           56            876        Jan
c1      1             2344          6          Jan
c2      876           57            986        Jan
c3      12            67            76         Jan
a1      1             3             67         feb
a2      9             7             32         feb
a3      12            67            76         feb
b1      1             3             67         feb
b2      9             7             32         feb
b3      12            67            76         feb
c1      1             3             67         feb
c2      9             7             32         feb
c3      12            67            76         feb
a1      66            2             9          mar
a2      32            7             1          mar
a3      12            67            76         mar
b1      66            2             9          mar
b2      32            7             1          mar
b3      12            67            76         mar
c1      66            2             9          mar
c2      32            7             1          mar
c3      12            67            76         mar

Answer 1

您可以使用CTE执行UPDATE：

;WITH ToUpdate AS (
   SELECT t1.col1, t1.california, t1.florida, t1.hawaii, t1.[date],  
          t2.california AS california_2, t2.florida AS florida_2, t2.hawaii AS hawaii_2
   FROM mytable AS t1
   JOIN mytable AS t2 
      ON t1.[date] = t2.[date] AND 
         (((t1.col1 IN ('a1', 'b1')) AND (t2.col1 = 'c1')) OR 
         ((t1.col1 IN ('a2', 'b2')) AND (t2.col1 = 'c2')) OR
         ((t1.col1 IN ('a3', 'b3')) AND (t2.col1 = 'c3')))
   WHERE t1.california = 0 AND t1.florida = 0 AND t1.hawaii = 0 AND
         t1.col1 IN ('a1', 'a2', 'a3', 'b1', 'b2', 'b3')
)
UPDATE ToUpdate
SET california = california_2,
    florida = florida_2,
    hawaii = hawaii_2

Demo here

Answer 2

老实说，我宁愿只是将你所拥有的数据重复插入到一个新表中：

CREATE PROC YourProc
DECLARE @Loop INT

AS

SET @Loop = 2
WHILE @Loop > 0
BEGIN

INSERT INTO newTable (col1, california, florida, hawaii)
SELECT DISTINCT col1, california, florida, hawaii   
FROM yourTable

SET @Loop = @Loop - 1
END

如何通过应用行方式更新表

2 个答案: