Question

I have This type of query when I execute it it return duplicate row in table,,
what’s the problem with this ?????

Declare @Keyword AS NVARCHAR(MAX) 
Set @Keyword = 'scale'


select DISTINCT * from (
    SELECT DISTINCT                           dbo.Product_Search.Product_Name,     dbo.Product_Search.Product_Code,
                              dbo.Product_Search.Product_ModelNo,  dbo.Brand_Master.Brand_Name,
                              dbo.Product_Search.Product_Kid,   dbo.Product_Search.Product_Image, 
                               dbo.Unit_Master.Unit_Name,   dbo.product_Search.CatName, 
                              dbo.product_Search.ProdName,  dbo.product_Search.ProductDescription, ROW_NUMBER() over(order by Product_Kid) as ROW

                    FROM      dbo.Product_Search INNER JOIN
                              dbo.Brand_Master ON dbo.Product_Search.Product_BrandId = dbo.Brand_Master.Brand_Kid LEFT OUTER JOIN
                              dbo.Category_Index_Master ON dbo.Product_Search.Product_CategoryId = dbo.Category_Index_Master.Category_Kid LEFT OUTER JOIN
                              dbo.Unit_Master ON dbo.Product_Search.Product_MarketPriceType = dbo.Unit_Master.Unit_Kid
                    WHERE     (dbo.Product_Search.Product_Name LIKE '%' + @Keyword + '%') 
                        OR      CategoryIndex_Name LIKE '%' + @Keyword + '%'
                        OR      Brand_Name LIKE '%' + @Keyword + '%'
                        OR      Product_ModelNo LIKE '%' + @Keyword + '%'
                        OR      Product_Code LIKE '%' + @Keyword + '%'
)h

Answer 1

Row_Number:
http://msdn.microsoft.com/en-us/library/ms186734.aspx

Returns the sequential number of a row within a partition of a result
set, starting at 1 for the first row in each partition

So you will have non-unique values always here. Let you try to move ROW to upward:

SELECT *,ROW_NUMBER() OVER ( ORDER BY Product_Kid ) AS ROW
FROM    ( SELECT DISTINCT
                    dbo.Product_Search.Product_Name ,
                    dbo.Product_Search.Product_Code ,
                    dbo.Product_Search.Product_ModelNo ,
                    dbo.Brand_Master.Brand_Name ,
                    dbo.Product_Search.Product_Kid ,
                    dbo.Product_Search.Product_Image ,
                    dbo.Unit_Master.Unit_Name ,
                    dbo.product_Search.CatName ,
                    dbo.product_Search.ProdName ,
                    dbo.product_Search.ProductDescription
          FROM      dbo.Product_Search
                    INNER JOIN dbo.Brand_Master ON dbo.Product_Search.Product_BrandId = dbo.Brand_Master.Brand_Kid
                    LEFT OUTER JOIN dbo.Category_Index_Master ON dbo.Product_Search.Product_CategoryId = dbo.Category_Index_Master.Category_Kid
                    LEFT OUTER JOIN dbo.Unit_Master ON dbo.Product_Search.Product_MarketPriceType = dbo.Unit_Master.Unit_Kid
          WHERE     ( dbo.Product_Search.Product_Name LIKE '%' + @Keyword
                      + '%' )
                    OR CategoryIndex_Name LIKE '%' + @Keyword + '%'
                    OR Brand_Name LIKE '%' + @Keyword + '%'
                    OR Product_ModelNo LIKE '%' + @Keyword + '%'
                    OR Product_Code LIKE '%' + @Keyword + '%'
        ) h