Using a comma-separated parameter in an IN clause

you can use split function and use it as in following way here my split fnSplitString return splitdata

select * from tb1 where id in(select splitdata from dbo.fnSplitString((select col1 from tb12 where id=3),','))


create FUNCTION [dbo].[fnSplitString] 
( 
    @string NVARCHAR(MAX), 
    @delimiter CHAR(1) 
) 
RETURNS @output TABLE(splitdata NVARCHAR(MAX) 
) 
BEGIN 
    DECLARE @start INT, @end INT 
    SELECT @start = 1, @end = CHARINDEX(@delimiter, @string) 
    WHILE @start < LEN(@string) + 1 BEGIN 
        IF @end = 0  
            SET @end = LEN(@string) + 1

        INSERT INTO @output(splitdata)  
        VALUES(SUBSTRING(@string, @start, @end - @start)) 
        SET @start = @end + 1 
        SET @end = CHARINDEX(@delimiter, @string, @start)

    END 
    RETURN 
END

If you are using SQL 2016 and above string_split you can use.

-- @param is where you keep your comma separated values example: 
declare @param = 'param1,param2,param3'
select * from table1 where col1 in (select TRIM(value) from string_split(@param,',')

More information about string_split check offical documemt

Furthermore, TRIM() is used to trim values from white spaces.

Try this one, Just need to add commas at the beginning and at the end of @params string.

Declare @params varchar(100) Set @params = ',param1,param2,param3,'

Select * from t
where CHARINDEX(','+cast(col1 as varchar(8000))+',', @params) > 0

SQL FIDDLE

We can use STRING_SPLIT() in SQL SERVER

DECLARE @params varchar(max)= 'param1,param2,param3'

SELECT *
FROM table1
WHERE col1 IN (SELECT value FROM STRING_SPLIT( @params , ','))