SQL : in clause in storedprocedure:how to pass values

Question

I want to write an SQL Server 2005 stored procedure which will select and return the user records from the user table for some userids which are passed to the stored procedure as parameter.

How to do this ?

I can pass the user ids as a string separated by comma. So that i can use the

select * from users where userid in (userids)

Ex : I want to select records for id's 5,6,7,8,9

How to write the stored procedure ?

Answer 1

you could use dynamic sql. Pass the in statement to a Sql SP via a variable and concatenate it into a query in the SQL and execute using sp_execute sql

create procedure myproc(@clause varchar(100)) as 
begin
  exec sp_executesql 'select * from users where userid in ( ' + @clause +' )'
end

Answer 2

For SQL Server 2005, check out Erland Sommarskog's excellent Arrays and Lists in SQL Server 2005 article which shows some techniques how to deal with lists and arrays in SQL Server 2005 (he also has another article for SQL Server 2000).

If you could upgrade to SQL Server 2008, you can use the new feature called "table valued parameter":

First, create a user-defined table type

CREATE TYPE dbo.MyUserIDs AS TABLE (UserID INT NOT NULL)

Secondly, use that table type in your stored procedure as a parameter:

CREATE PROC proc_GetUsers @UserIDTable MyUserIDs READONLY 
AS
SELECT * FROM dbo.Users
    WHERE userid IN (SELECT UserID FROM @UserIDTable)

See details here.

Marc

Answer 3

Assuming T-SQL, you can use this nice function (that returns a table).

DROP FUNCTION sp_ConvertStringToTable
GO
CREATE FUNCTION sp_ConvertStringToTable(@list ntext)
      RETURNS @tbl TABLE (Position INT IDENTITY(1, 1) NOT NULL,
                          Value INT NOT NULL) AS
   BEGIN
      DECLARE @pos      int,
              @textpos  int,
              @chunklen smallint,
              @str      nvarchar(4000),
              @tmpstr   nvarchar(4000),
              @leftover nvarchar(4000)

      SET @textpos = 1
      SET @leftover = ''
      WHILE @textpos <= datalength(@list) / 2
      BEGIN
         SET @chunklen = 4000 - datalength(@leftover) / 2
         SET @tmpstr = ltrim(@leftover + substring(@list, @textpos, @chunklen))
         SET @textpos = @textpos + @chunklen

         SET @pos = charindex(' ', @tmpstr)
         WHILE @pos > 0
         BEGIN
            SET @str = substring(@tmpstr, 1, @pos - 1)
            INSERT @tbl (Value) VALUES(convert(int, @str))
            SET @tmpstr = ltrim(substring(@tmpstr, @pos + 1, len(@tmpstr)))
            SET @pos = charindex(' ', @tmpstr)
         END

         SET @leftover = @tmpstr
      END

      IF ltrim(rtrim(@leftover)) <> ''
         INSERT @tbl (Value) VALUES(convert(int, @leftover))

      RETURN
   END   
GO

In this way:

SELECT * FROM Users 
WHERE userid IN 
( SELECT Value FROM sp_ConvertStringToTable('1 2 3') )

You can change the stored function to work with comma separated strings instead of space separated ones.

If you don't want / can't use a stored function you can include the code of it inside the stored procedure where needed.

EDIT: this is incredibly more performant than the string concatenation.

Answer 4

This is a common question. I have an option here:

http://stackoverflow.com/questions/977021/can-a-stored-procedure-have-dynamic-parameters-to-be-used-in-an-in-clause/977114#977114

Answer 5

see my previous answer to this

this is the best source:

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

create a split function, and use it like:

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

I prefer the number table approach

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

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:

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:

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:

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