Any Advice For Making That Stored Pro. Better?

Hi sir ,
That is my Stored pro. which search in Sales table .
- I do NOT know which parameters will be sent and which will be null.
- I write sqlString which dynamically changed based on which parameters sent.

Here is my code:




Code Snippet
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Alter PROCEDURE SearchInSales
@ID bigint,
@AmmountPaid bigint,
@AmmountDelayed bigint,
@Quantity bigint
AS
BEGIN

SET NOCOUNT ON;
Declare @sqlStr nvarchar(200)
set @sqlStr='SELECT * FROM Sales WHERE '

if @ID is not null

set @sqlStr = @sqlStr + 'ID = ' + cast(@ID as nvarchar(50))
else

BEGIN

if @AmmountPaid is not null

set @sqlStr = @sqlStr + 'AmmountPaid = ' + cast(@AmmountPaid as nvarchar(50))
if @AmmountDelayed is not null

BEGIN

if len(@sqlStr)>25 -- check if @sqlStr has any of pre. conditions
set @sqlStr = @sqlStr + ' AND '
set @sqlStr = @sqlStr + 'AmmountDelayed = ' + cast(@AmmountDelayed as nvarchar(50))
END
if @Quantity is not null

BEGIN

if len(@sqlStr)>25 -- check if @sqlStr has any of pre. conditions
set @sqlStr = @sqlStr + ' AND '
set @sqlStr = @sqlStr + 'Quantity = ' + cast(@Quantity as nvarchar(50))
END
END



EXEC(@sqlStr)

END
GO







Is there way better than I did?