first create function after call that function in your query...

Text

CREATE FUNCTION SPLIT(@VAL VARCHAR(MAX))

RETURNS @T1 TABLE(COL1 VARCHAR(MAX))

AS

BEGIN

WHILE CHARINDEX(',',@VAL)>0

BEGIN

INSERT INTO @T1 VALUES(SUBSTRING(@VAL,1,(CHARINDEX(',',@VAL))-1))

SET @val=SUBSTRING(@VAL,(CHARINDEX(',',@VAL))+1,LEN(@VAL))

END

INSERT INTO @T1 VALUES(@VAL)

RETURN

END

SELECT

Persons.P_id

,Persons.LastName

,Persons.FirstName

,Persons.Address

,Persons.City

FROM

Persons

where Persons.P_id IN (select * FROM split(@P_id))