Question

我有以下代码，问题是我的变量列表@LocationList本质上是一个csv字符串。当我使用它作为（@LocationList）中LocationID的一部分时，它表示它不是一个int（LocationID是一个int）。如何让这个csv字符串被teh in子句接受？

Declare @LocationList varchar(1000)
Set @LocationList = '1,32'

select Locations from table where Where LocationID in (@LocationList)

Answer 1

最有效的方法是使用动态SQL，例如rt2800提及（Michael Allen的注入警告）

但是你可以创造一个功能：

ALTER  FUNCTION [dbo].[CSVStringsToTable_fn] ( @array VARCHAR(8000) )
RETURNS @Table TABLE ( value VARCHAR(100) )
AS 
    BEGIN
        DECLARE @separator_position INTEGER,
            @array_value VARCHAR(8000)  

        SET @array = @array + ','

        WHILE PATINDEX('%,%', @array) <> 0 
            BEGIN
                SELECT  @separator_position = PATINDEX('%,%', @array)
                SELECT  @array_value = LEFT(@array, @separator_position - 1)

                INSERT  @Table
                VALUES  ( @array_value )

                SELECT  @array = STUFF(@array, 1, @separator_position, '')
            END
        RETURN
    END

并从中选择：

DECLARE @LocationList VARCHAR(1000)
SET @LocationList = '1,32'

SELECT  Locations 
FROM    table
WHERE   LocationID IN ( SELECT   *
                           FROM     dbo.CSVStringsToTable_fn(@LocationList) )

OR

SELECT  Locations
FROM    table loc
        INNER JOIN dbo.CSVStringsToTable_fn(@LocationList) list
            ON list.value = loc.LocationID

当您尝试从SSRS向PROC发送多值列表时，这非常有用。

Answer 2

我经常有这个要求，而有时，如果你很清楚你要搜索的列[大小/格式/长度]，你可以做一种REGEX。

这样的事情：

  DECLARE @MyListOfLocation varchar(255)
  set @MyListOfLocation  = '|1|32|36|24|3|'

  Select LocationID 
  from  Table 
  where @MyListOfLocation like '%|' +  LocationID + '|%'

注意：PIPE字符用于保护查询不返回包含单个字符的任何LocationID（例如＆＃39; 1＆＃39;）。

这是一个完整的工作示例：

DECLARE @MyListOfLocation varchar(255)
set @MyListOfLocation  = '|1|11|21|'

SELECT LocationName
FROM (
        select '1' as LocationID, 'My Location 1' as LocationName
        union all
        select '11' as LocationID, 'My Location 11' as LocationName
        union all
        select '12' as LocationID, 'My Location 12' as LocationName
        union all
        select '13' as LocationID, 'My Location 13' as LocationName
        union all
        select '21' as LocationID, 'My Location 21' as LocationName
    ) as MySub
where @MyListOfLocation like '%|' + LocationID + '|%'

警告！这种方法不是索引友好的！

如果你想在所有这些中添加一些IN（@MyListOfLocation），为了利用INDEXES，你可以将脚本修改为：

SELECT MyDATA.* 
FROM   HugeTableWithAnIndexOnLocationID as MyDATA 
WHERE  LocationID in (
      Select LocationID 
      from  Table 
      where @MyListOfLocation like '%|' +  LocationID + '|%')

Answer 3

declare @querytext Nvarchar(MAX)

set @querytext = 'select Locations from table where Where LocationID in (' + @LocationList + ');';

exec sp_executesql @querytext;

（@Variable）查询中的SQL

3 个答案: