i cant understand how can take unique column (remove duplication) from a table
which compare with another table data.
in my case
i have two table
i want to get unique rows from tblproduct after compireing with tblviewer as
[in table viewer first taking viewerid after that taking productid in viewer table afterthat compire with tblproduct.
actualy like that
if i take vieweris=123 two row productid select 12001&11001 after that this tblproduct productid and finaly taking the row from tblproduct which maching.
where productid =
where viewerid = 123
There are a few ways to do this. You can do a standard
INNER JOIN to the table to filter the results:
Select Distinct P.* From tblProduct P Join tblViewer V On V.ProductId = P.ProductId Where V.ViewerId = 123
Alternatively, you could use
EXISTS as well - this eliminates the need to use a
Select * From tblProduct P Where Exists ( Select * From tblViewer V Where V.ProductId = P.ProductId And V.ViewerId = 123 )
Or, you could also use an
IN, as suggested by the other answers:
Select * From tblProduct Where ProductId In ( Select ProductId From tblViewer Where ViewerId = 123 )