Question

My output is not as I expected, what i want is eliminated duplicated data. i tried to use group by and distinct before but it doesn’t work.=(

data in my database

who are u?   A
who are u?   B
who are u?   C
who am i?    A
who am i?    B
who am i?    C

current output

Column ‘ExerciseTable.r1’ is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

expected output

who are u? A
           B
           C

Who am i?  A
           B
           C

---

<asp:SqlDataSource ID="SqlDataSource2" runat="server" 
 ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
 SelectCommand="SELECT [Question],[r1] FROM [ExerciseTable] GROUP BY [Question]">

</asp:SqlDataSource>

Answer 1

In your SQL Statement(c1 first column, c2 second column) :

Select 
case when t.[RN]>1 and t.[RN]<>4 then  '' else t.c1 end [c1],
t.c2 from
(
Select ROW_NUMBER() OVER (ORDER BY c1) AS [RN],c1,c2 from t1
) as t

Without a fixed RowNumber (t.[RN]) :

Select 
case 
when 
t.[RN]=( 
    Select min([RN]) from
    (
    Select  ROW_NUMBER() OVER (ORDER BY c1)  AS [RN],c1,c2 from t1 
    ) as t where c1='who am i?'
)   
or 
t.[RN]=(
    Select min([RN]) from
    (
    Select  ROW_NUMBER() OVER (ORDER BY c1)  AS [RN],c1,c2 from t1 
    ) as t where c1='who are u?'
) then  t.c1 else '' end [c1],
t.c2 from
        (
        Select ROW_NUMBER() OVER (ORDER BY c1) AS [RN],c1,c2 from t1
        ) as t

Or you can iterate thru the result set (Eg:a List) using C#/VB.Net and remove the data on the column for the following rows after the first one having ‘who am i?’ and the same for ‘who are u?’