SqlHelper.ExecuteReader() throws an exception when no results found - sql-server

Question

I have an SqlDataReader that is declared like this:
Dim myReader As SqlDataReader
myReader = SqlHelper.ExecuteReader(ConnectionString, "storedProcedure1", CInt(myTextBox.Text))
Later I use the results like this:
If myReader.HasRows Then
While myReader.Read()
Row = Table1.NewRow()
Row.Item("REF") = myReader.GetString(0)
Row.Item("CD") = myReader.GetString(1)
Row.Item("NAME") = myReader.GetString(2)
Row.Item("KEY") = myReader.GetDecimal(3)
Row.Item("STRING") = myReader.GetString(0) & " - " & myReader.GetString(1) & " - " & myReader.GetString(2).ToString().Replace("'", "") & " - " & myReader.GetString(4).ToString().Replace("'", "")
Table1.Rows.Add(Row)
'Fill Drop Down
drpMenu.Items.Add(New ListItem(myReader.GetString(0) & " - " & myReader.GetString(1) & " - " & myReader.GetString(2).ToString().Replace("'", "") & " - " & myReader.GetString(4).ToString().Replace("'", "")))
End While
End If
myTextBox is a textbox that the user enters a possible location number that gets searched for using the stored procedure. If the user enters a valid location number, this works great and I have no problems. If they enter a non-existent location number, I get an exception:
System.IndexOutOfRangeException: Index was outside the bounds of the array.
I would think that the If myReader.HasRows line would keep me from trying to read and manipulate results that don't exist but there must be something I'm missing. myTextBox is already being validated elsewhere in the code to make sure the user typed in an integer without any wacky characters so bad input doesn't seem to be the problem either.
How do I find out whether the location number exists before calling SqlHelper.ExecuteReader()? Or maybe the better question is how do I gracefully handle this exception and tell the user the location wasn't found?
EDIT: Here's the stored procedure.
ALTER PROCEDURE [dbo].[storedProcedure]
-- Add the parameters for the stored procedure here
#MBR as integer
AS
BEGIN
EXEC ('{CALL RM#IMLIB.spGETLOC( ?)}', #MBR) at AS400
END
EDIT #2: When I run the stored procedure in SMS and pass a valid location, it returns what I expect. If I pass an invalid location number, it returns nothing.

Answer 1

First. create a local variable...and cast the textbox value to the local variable...to make sure that isn't the error.
dim myValue as Int32
myValue = '' convert textbox value to an int.
Second...typically, my datareader code looks like this.
If (Not ( reader Is Nothing) ) then
If reader.HasRows Then
Do While reader.Read()
Console.WriteLine(reader.GetInt32(0) _
& vbTab & reader.GetString(1))
Loop
End If
End If
(You'll have to adjust the GetInt32 or GetString and the ordinal number to your specific case of course).
My guess is that your child-procedure (RM#IMLIB.spGETLOC) has logic in it that does NOT return a row if there isn't a match.
You can still return a result....that has no rows in it. ** (Read that again).
For example
Select ColA, ColB from dbo.MyTable where 0=1
This will return a result, with no rows. That is different from not returning a(ny) select statement..(Read that again)
My guess is that this little nuance is where you get an issue.
APPEND:
If you cannot change the child-stored procedure....
Create a #TempTable...
Populate the #TempTable with the child-stored procedure.
Do a select from the #TempTable.
Here is a generic example:
IF OBJECT_ID('tempdb..#TempOrders') IS NOT NULL
begin
drop table #TempOrders
end
CREATE TABLE #TempOrders
(
ColumnA int
, [ColumnB] nchar(5)
)
/* Note, your #temp table must have the exact same columns as returned by the child procedure */
INSERT INTO #TempOrders ( ColumnA, ColumnB )
exec dbo.uspChildProcedure ParameterOne
Select ColumnA, ColumnB from #TempOrders
IF OBJECT_ID('tempdb..#TempOrderDetails') IS NOT NULL
begin
drop table #TempOrderDetails
end

Answer 2

I finally figured out my issue.
Later in my code, I had a DataRow array that was empty if the location couldn't be found. I was getting the exception because it was trying to grab an Item from array(0) which makes complete sense.
I missed it initially because I thought it was a DataRow, not a DataRow array. Man, I hate fixing up code I didn't write...