将列与t-sql中的值列表进行比较

I have a situation where I am displaying records on a page, and I need a way for the user to select a subset of those records to be displayed on another page. These records aren't stored anywhere then, it is a dynamically generated thing. I know I could use jquery to pass in a comma-separated value to my other web page, but I'm not sure what is the best way to in sql say where uniqueid is in this list of ids not in a table etc. I know I could dynamically construct the sql with a bunch of ors, but that seems like a hack. anyone else have any suggestions?

我有一种情况,我在页面上显示记录,我需要一种方法让用户选择要在另一页上显示的那些记录的子集。这些记录不存储在任何地方,它是动态生成的东西。我知道我可以使用jquery将逗号分隔的值传递给我的其他网页,但是我不确定在sql中最好的方法是说哪个uniqueid在这个id列表中不在表等中我知道我可以用一堆ors动态构造sql,但这看起来像是一个黑客。还有其他人有什么建议吗?

2 个解决方案

#1

this is the best source:

这是最好的来源:

http://www.sommarskog.se/arrays-in-sql.html

create a split function, and use it like:

创建一个split函数,并使用它:

SELECT
    *
    FROM YourTable  y
    INNER JOIN dbo.splitFunction(@Parameter) s ON y.ID=s.Value

I prefer the number table approach

我更喜欢数字表方法

For this method to work, you need to do this one time table setup:

要使此方法起作用,您需要执行以下一次性表设置:

SELECT TOP 10000 IDENTITY(int,1,1) AS Number
    INTO Numbers
    FROM sys.objects s1
    CROSS JOIN sys.objects s2
ALTER TABLE Numbers ADD CONSTRAINT PK_Numbers PRIMARY KEY CLUSTERED (Number)

Once the Numbers table is set up, create this function:

设置Numbers表后,创建此功能:

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 TABLE
AS
RETURN 
(

    ----------------
    --SINGLE QUERY-- --this will not return empty rows
    ----------------
    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!=''

);
GO 

You can now easily split a CSV string into a table and join on it:

您现在可以轻松地将CSV字符串拆分为表格并加入其中:

select * from dbo.FN_ListToTable(',','1,2,3,,,4,5,6777,,,')

OUTPUT:

ListValue
-----------------------
1
2
3
4
5
6777

(6 row(s) affected)

Your can pass in a CSV string into a procedure and process only rows for the given IDs:

您可以将CSV字符串传递到过程中,并仅处理给定ID的行:

SELECT
    y.*
    FROM YourTable y
        INNER JOIN dbo.FN_ListToTable(',',@GivenCSV) s ON y.ID=s.ListValue

#2

You can use the solution Joel Spolsky recently gave for this problem.

你可以使用Joel Spolsky最近解决这个问题的解决方案。

SELECT * FROM MyTable
WHERE ',' + 'comma,separated,list,of,words' + ','
  LIKE '%,' + MyTable.word + ',%';

That solution is clever but slow. The better solution is to split the comma-separated string, and construct a dynamic SQL query with the IN() predicate, adding a query parameter placeholder for each element in your list of values:

这个解决方案很聪明但很慢。更好的解决方案是拆分以逗号分隔的字符串,并使用IN()谓词构造动态SQL查询,为值列表中的每个元素添加查询参数占位符:

SELECT * FROM MyTable
WHERE word IN ( ?, ?, ?, ?, ?, ?, ?, ? );

The number of placeholders is what you have to determine when you split your comma-separated string. Then pass one value from that list per parameter.

分割逗号分隔的字符串时,必须确定占位符的数量。然后从每个参数的列表中传递一个值。

If you have too many values in the list and making a long IN() predicate is unwieldy, then insert the values to a temporary table, and JOIN against your main table:

如果列表中包含太多值并且使得长IN()谓词不实用,则将值插入临时表,并对主表进行JOIN:

CREATE TEMPORARY TABLE TempTableForSplitValues (word VARCHAR(20));

...split your comma-separated list and INSERT each value to a separate row...

SELECT * FROM MyTable JOIN TempTableForSplitValues USING (word);

Also see many other similar questions on SO, including:

另请参阅关于SO的许多其他类似问题,包括:

• Dynamic SQL Comma Delimited Value Query

动态SQL逗号分隔值查询

• Passing a varchar full of comma delimited values to a SQL Server IN function

将一个充满逗号分隔值的varchar传递给SQL Server IN函数

• Parameterized Queries with Like and In

具有Like和In的参数化查询

• Parameterizing a SQL IN clause?

参数化SQL IN子句?