you can use it with IN clause

change you code to something like this

Dim strSQL As String = "SELECT * FROM Author WHERE ID IN (" + IDs +
")"

and get rid of SqlParameter

You cannot do it the way you are attempting to do it. There are a couple of
ways around this.

The first is the one shown in your discussion with Alexy, where you
concatenate the ids string to the SQL string. This is fairly simple, but
cannot be done with a single @ids parameter, as you are not truly
parameterizing at this time. NOTE: If you adopt this method, you have the
potential of SQL injection.

Another method is to pass XML into SQL Server, with each ID in a separate
element. You can then join to the XML in a stored procedure and return the
results. This is similar to the IN, but immune from SQL injection.

*************************************************

I use an IN clause with a parameterized query in a similar scenario to
the one you want to use. However I get the results for my in clause
from a function returning a single column.  I include it below. This
takes a string of integer comma separated values as input and returns
a table with a single column.

Here is a snippet of SQL using this function:

ConsultantID In (Select * From
dbo.CSV_IntegersToSingleColumn(@ConsultantIDs))

-- PS: Homage to the guy who wrote this. Sorry I lost the Url where it
came from.
-- Convert string of integer comma separated values (input) to a table
of integers (return value).
ALTER FUNCTION [dbo].[CSV_IntegersToSingleColumn]
(
   @cslist VARCHAR(8000)
)
RETURNS @t TABLE
(
   Item VARCHAR(64)
)
BEGIN
   DECLARE @spot SMALLINT, @str VARCHAR(8000), @sql VARCHAR(8000)

   WHILE @cslist <> ''
   BEGIN
       SET @spot = CHARINDEX(',', @cslist)
       IF @spot > 0
           BEGIN
               SET @str = LEFT(@cslist, @spot - 1)
               SET @cslist = RIGHT(@cslist, LEN(@cslist) - @spot)
           END
       ELSE
           BEGIN
               SET @str = @cslist
               SET @cslist = ''
           END
       INSERT @t SELECT @str
   END
   RETURN
END