在SQL Server中迭代字符串列表？

时间：2016-07-15 04:58:26

标签： sql sql-server tsql

如何在T-SQL中访问列表中的值？

我有一个SQL语句循环并计算值在Table_1中的特定列中出现的次数。然后它将所需的值插入到Table_2的列中，或者如果该行不存在，则会添加一个新行并添加必要的数据。

我准确地创建了列表或表，

DECLARE @MyList TABLE (Value NVARCHAR(50))
INSERT INTO @MyList VALUES ('Data1')
INSERT INTO @MyList VALUES ('Data2')
INSERT INTO @MyList VALUES ('Data3')
INSERT INTO @MyList VALUES ('Data4')
INSERT INTO @MyList VALUES ('Data5')
INSERT INTO @MyList VALUES ('Data6')
INSERT INTO @MyList VALUES ('Data7')
INSERT INTO @MyList VALUES ('Data8')

该语句工作正常，但我有所有硬编码，我想添加一些动态数据插入，所以我创建了一个值列表（字符串）。现在我无法按照我的方式访问这些值。

这是整个陈述，

DECLARE @cnt INT = 1;
DECLARE @MyList TABLE (Value NVARCHAR(50))
INSERT INTO @MyList VALUES ('Data1')
INSERT INTO @MyList VALUES ('Data2')
INSERT INTO @MyList VALUES ('Data3')
INSERT INTO @MyList VALUES ('Data4')
INSERT INTO @MyList VALUES ('Data5')
INSERT INTO @MyList VALUES ('Data6')
INSERT INTO @MyList VALUES ('Data7')
INSERT INTO @MyList VALUES ('Data8')

                        WHILE @cnt < 9
                        BEGIN

                            IF EXISTS (SELECT * FROM Staff_Manager.dbo.Staff_Count_TBL WHERE Staff_No = 3201 AND Year_D = 2016 AND Month_D = 6 AND Column_Index = @cnt)
                                BEGIN
                                  UPDATE Staff_Manager.dbo.Staff_Count_TBL 
                                            SET Column_Value = (
                                                 SELECT COUNT(*)  
                                                 FROM Staff_Manager.dbo.Staff_Time_TBL
                                                 WHERE Staff_No = 3201 AND Date_Data BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = 'Data_1'
                                                 GROUP BY Staff_No, Info_Data),
                                                 Column_Value2 = 'Data1'
                                                 WHERE Staff_No = 3201 AND Year_D = 2016 AND Month_D = 6 AND Column_Index = @cnt
                                END
                            ELSE
                                BEGIN
                                   INSERT INTO Staff_Manager.dbo.Staff_Count_TBL 
                                        (Staff_No, Year_D, Month_D, Column_Index, Column_Value, Column_Value2)
                                        SELECT 3201, 2016, 6, @cnt, COUNT(*), 'Data1' 
                                             FROM Staff_Manager.dbo.Staff_Time_TBL
                                             WHERE Staff_No = 3201 AND Date_Data BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = 'Data1' 
                                             GROUP BY Staff_No, Info_Data
                                END
                            SET @cnt = @cnt + 1
                        END

我想要实现的是遍历一个包含8个项目的列表，并将这些值输入到相应的列中。

例如，

在这一行，我已经硬编码Data1，

WHERE Staff_No = 3201 AND Date_Data 
       BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = 'Data1'

我想做的就是这个，

WHERE Staff_No = 3201 AND Date_Data 
       BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = @MyList[@cnt]

而且，

SELECT 3201, 2016, 6, @cnt, COUNT(*), @MyList[@cnt] 
                     FROM Staff_Manager.dbo.Staff_Time_TBL                           
                     WHERE Staff_No = 3201 AND Date_Data 
                    BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = @MyList[@cnt]

但这不起作用。在研究了一点之后，我发现T-SQL实际上并没有列出一个列表，而是一个临时表可以说，你需要从中获取值。不幸的是，我似乎无法工作。

我有一个UPDATE和一个INSERT语句，我需要从列表中添加值。

编辑：最后一分钟代码调整，

DECLARE @cnt INT = 1;
DECLARE @MyList TABLE (Value NVARCHAR(50))
INSERT INTO @MyList VALUES ('Data1')
INSERT INTO @MyList VALUES ('Data2')
INSERT INTO @MyList VALUES ('Data3')
INSERT INTO @MyList VALUES ('Data4')
INSERT INTO @MyList VALUES ('Data5')
INSERT INTO @MyList VALUES ('Data6')
INSERT INTO @MyList VALUES ('Data7')
INSERT INTO @MyList VALUES ('Data8') 
INSERT INTO @MyList VALUES ('Data9')
INSERT INTO @MyList VALUES ('Data10')
INSERT INTO @MyList VALUES ('Data11')
INSERT INTO @MyList VALUES ('Data12')
INSERT INTO @MyList VALUES ('Data13')
INSERT INTO @MyList VALUES ('Data14')
INSERT INTO @MyList VALUES ('Data15')
INSERT INTO @MyList VALUES ('Data16')
INSERT INTO @MyList VALUES ('Data17')
INSERT INTO @MyList VALUES ('Data18')
INSERT INTO @MyList VALUES ('Data19')
INSERT INTO @MyList VALUES ('Data20')
INSERT INTO @MyList VALUES ('Data21')
INSERT INTO @MyList VALUES ('Data22')
INSERT INTO @MyList VALUES ('Data23')
INSERT INTO @MyList VALUES ('Data24')
INSERT INTO @MyList VALUES ('Data25')
INSERT INTO @MyList VALUES ('Data26')
INSERT INTO @MyList VALUES ('Data27')
INSERT INTO @MyList VALUES ('Data28')
INSERT INTO @MyList VALUES ('Data29')
INSERT INTO @MyList VALUES ('Data30')

DECLARE @COUNTER INT = 0;
DECLARE @MAX INT = (SELECT COUNT(*) FROM @MyList)
DECLARE @VALUE VARCHAR(50);


                        WHILE @cnt <= @MAX  
                        BEGIN
                        SET @VALUE = (SELECT Value FROM @MyList 
                            ORDER BY 1 OFFSET @COUNTER 
                            ROWS FETCH NEXT 1 ROWS ONLY);


                            PRINT @cnt
                            PRINT @VALUE
                            PRINT @COUNTER

                            IF EXISTS (SELECT * FROM Staff_Manager.dbo.Staff_Count_TBL WHERE Staff_No = 3005 AND Year_D = 2016 AND Month_D = 6 AND Column_Index = @cnt)
                                BEGIN
                                  UPDATE Staff_Manager.dbo.Staff_Count_TBL 
                                            SET Column_Value = (
                                                 SELECT COUNT(*)  
                                                 FROM Staff_Manager.dbo.Staff_Time_TBL
                                                 WHERE Staff_No = 3005 AND Date_Data BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = @value
                                                 GROUP BY Staff_No, Info_Data),
                                                 Column_Value2 = @value
                                                 WHERE Staff_No = 3005 AND Year_D = 2016 AND Month_D = 6 AND Column_Index = @cnt
                                END
                            ELSE
                                BEGIN
                                   INSERT INTO Staff_Manager.dbo.Staff_Count_TBL 
                                        (Staff_No, Year_D, Month_D, Column_Index, Column_Value, Column_Value2)
                                        SELECT 3005, 2016, 6, @cnt, COUNT(*), @value 
                                             FROM Staff_Manager.dbo.Staff_Time_TBL
                                             WHERE Staff_No = 3005 AND Date_Data BETWEEN '2016/6/1' AND '2016/7/1' AND Info_Data = @value 
                                             GROUP BY Staff_No, Info_Data
                                END
                            SET @cnt = @cnt + 1
                            SET @COUNTER = @COUNTER + 1
                        END

1 个答案:

答案 0 :(得分：18)

您创建的不是列表而是表变量。那么如何迭代一张桌子。下面是一个简单的例子，如果您理解，我认为您可以继续：

（注意：在性能和大型表格方面，游标效率不高） 

select * from iwdata.IW_MASTER_LOG
WHERE TRUNC(EXECUTION_START_DATE)=TRUNC(SYSDATE)  
AND (EXECUTION_START_DATE-EXECUTION_ENDED_DATE) >to_date('40','mi');

<强>打印 

DECLARE @MyList TABLE (Value NVARCHAR(50))
INSERT INTO @MyList VALUES ('Data1')
INSERT INTO @MyList VALUES ('Data2')
INSERT INTO @MyList VALUES ('Data3')
INSERT INTO @MyList VALUES ('Data4')
INSERT INTO @MyList VALUES ('Data5')
INSERT INTO @MyList VALUES ('Data6')
INSERT INTO @MyList VALUES ('Data7')
INSERT INTO @MyList VALUES ('Data8')

DECLARE @value VARCHAR(50)

DECLARE db_cursor CURSOR FOR  
SELECT Value FROM @MyList
OPEN db_cursor   
FETCH NEXT FROM db_cursor INTO @value   

WHILE @@FETCH_STATUS = 0   
BEGIN   
       PRINT @value

       -- PUT YOUR LOGIC HERE
       -- MAKE USE OR VARIABLE @value wich is Data1, Data2, etc...

       FETCH NEXT FROM db_cursor INTO @value   
END   

CLOSE db_cursor   
DEALLOCATE db_cursor

所以你有@value变量Data1 Data2 Data3 Data4 Data5 Data6 Data7 Data8 ，Data等。我认为这解决了你的问题。

替代方法是使用Data2循环+ WHILE + OFFSET：

FETCH NEXT

你得到相同的结果

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