在SQL Server中迭代字符串列表？

Question

如何在T-SQL中访问列表中的值？

我有一个循环的SQL语句,并计算值在特定列中出现的次数Table_1.然后它将所需的值插入到它们的列中,Table_2或者如果该行不存在,它会添加一个新行并添加必要的数据.

我确切地创建了列表或表,

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,并将这些值输入到它们的相应列中.

例如,

在这条线上,我有硬编码Data1,

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

我想做的是这个,

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

还有这个,

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,我似乎无法得到任何工作.

我有UPDATE一个INSERT声明,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

Answer 1

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:在性能和大表方面,游标效率不高)

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

打印:

Data1
Data2
Data3
Data4
Data5
Data6
Data7
Data8

所以你有@value变量Data,Data2...等.我认为这解决了你的问题.

另一种方法是使用WHILE循环+ OFFSET+ FETCH NEXT:

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

WHILE @COUNTER < @MAX
BEGIN

SET @VALUE = (SELECT VALUE FROM
      (SELECT (ROW_NUMBER() OVER (ORDER BY (SELECT NULL))) [index] , Value from @MyList) R 
       ORDER BY R.[index] OFFSET @COUNTER 
       ROWS FETCH NEXT 1 ROWS ONLY);

PRINT @VALUE

SET @COUNTER = @COUNTER + 1

END

你得到相同的结果