将充满逗号分隔值的varchar传递给SQL Server IN函数

Question

我有一个SQL Server存储过程，我想在其中将一个varchar完整的逗号分隔值传递给一个IN函数。例如：

DECLARE @Ids varchar(50);
SET @Ids = '1,2,3,5,4,6,7,98,234';

SELECT * 
FROM sometable 
WHERE tableid IN (@Ids);

当然这是行不通的。我得到了错误：

将varchar值‘1,2,3,5,4,6,7,98,234’转换为数据类型int时转换失败。

如何在不借助动态SQL的情况下完成此任务（或相对类似的任务）？

Answer 1

不要使用循环拆分字符串的函数！ ，我下面的函数将非常快速地拆分字符串，而且不会循环！

在使用我的函数之前，您需要设置一个“帮助器”表，每个数据库只需要执行一次此操作：

CREATE TABLE Numbers
(Number int  NOT NULL,
    CONSTRAINT PK_Numbers PRIMARY KEY CLUSTERED (Number ASC)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
DECLARE @x int
SET @x=0
WHILE @x<8000
BEGIN
    SET @x=@x+1
    INSERT INTO Numbers VALUES (@x)
END

使用此函数来拆分您的字符串，该字符串不会循环并且非常快：

CREATE FUNCTION [dbo].[FN_ListToTable]
(
     @SplitOn              char(1)              --REQUIRED, the character to split the @List string on
    ,@List                 varchar(8000)        --REQUIRED, the list to split apart
)
RETURNS
@ParsedList table
(
    ListValue varchar(500)
)
AS
BEGIN

/**
Takes the given @List string and splits it apart based on the given @SplitOn character.
A table is returned, one row per split item, with a column name "ListValue".
This function workes for fixed or variable lenght items.
Empty and null items will not be included in the results set.


Returns a table, one row per item in the list, with a column name "ListValue"

EXAMPLE:
----------
SELECT * FROM dbo.FN_ListToTable(',','1,12,123,1234,54321,6,A,*,|||,,,,B')

    returns:
        ListValue  
        -----------
        1
        12
        123
        1234
        54321
        6
        A
        *
        |||
        B

        (10 row(s) affected)

**/



----------------
--SINGLE QUERY-- --this will not return empty rows
----------------
INSERT INTO @ParsedList
        (ListValue)
    SELECT
        ListValue
        FROM (SELECT
                  LTRIM(RTRIM(SUBSTRING(List2, number+1, CHARINDEX(@SplitOn, List2, number+1)-number - 1))) AS ListValue
                  FROM (
                           SELECT @SplitOn + @List + @SplitOn AS List2
                       ) AS dt
                      INNER JOIN Numbers n ON n.Number < LEN(dt.List2)
                  WHERE SUBSTRING(List2, number, 1) = @SplitOn
             ) dt2
        WHERE ListValue IS NOT NULL AND ListValue!=''



RETURN

END --Function FN_ListToTable

您可以将此函数用作联接中的表：

SELECT
    Col1, COl2, Col3...
    FROM  YourTable
        INNER JOIN FN_ListToTable(',',@YourString) s ON  YourTable.ID = s.ListValue

这是您的示例：

Select * from sometable where tableid in(SELECT ListValue FROM dbo.FN_ListToTable(',',@Ids) s)