RETURN DISTINCT ROW IN SQL DATASET

Question

User1909155429 posted

I WANT TO FIND UNIQUE ROWS FROM MY TABLE.MY SQL STAEMENT IS AS FOLLOWS:

  Dim selectStatement As String _
               = "SELECT DISTINCT Email, firstname,LastName, AddressLine1, City, County, PostalCode,InvoiceNumber,Delivery.UserID " _
            & "FROM Delivery join Invoices on Delivery.UserID=Invoices.UserID " _
              & "WHERE (firstname LIKE @firstname)AND (LastName LIKE @LastName)"

THIS DOES NOT RETURN UNIQUE ROWS SO I TEND TO USE LINQ METHOD TO REMOVE DUPLICATE. BUT I AM SURE IT CAN BE

FOUND DIRECT FROM TABLE?

Answer 1

User303363814 posted

THIS DOES NOT RETURN UNIQUE ROWS

Can you show an actual query and the actual results where you are seeing this?

Answer 2

User-939850651 posted

Hi peterthegreat,

According to the query statement you provided, I think the reason why you did not get the expected result may be:

 Dim selectStatement As String _
               = "SELECT DISTINCT Email, firstname,LastName, AddressLine1, City, County, PostalCode,InvoiceNumber,Delivery.UserID " _
            & "FROM Delivery join Invoices on Delivery.UserID=Invoices.UserID " _
              & "WHERE (firstname LIKE @firstname) AND (LastName LIKE @LastName)"

You used fuzzy query in the query statement, I am not sure if you understand its effect. 

I am wondering whether the conditions should be:

WHERE (firstname = @firstname) AND (LastName = @LastName)

If I misunderstood something, could you provide more details?

Best regards,

Xudong Peng