executescalar() method

[buran]

Dear .NET Programmers,

I use the following code snippet but can't figure out what is going wrong
since the result object equals to nothing although it shouldn't be

Function CheckMFileToBeClosed() As Boolean
Dim result As Object
myCommand.Parameters.Clear()
myCommand.CommandText = "SELECT Result = CASE WHEN DischargeDate IS NULL
THEN 1 " & _
"ELSE 0 END " & _
"FROM dbo.MedicalFollowUpInHospital " & _
"WHERE OurFileNo = @medicalFileNo"
myCommand.CommandType = CommandType.Text
myCommand.Parameters.Add("@medicalFileNo", Session("selectedFileNumber")
+ "M")
result = myCommand.ExecuteScalar()
If CInt(result) = 1 Then
Return False
Else
Return True
End If
End Function

Thanks in advance,

Buran

 

[Marc Hoeppner]

Hi,

my guess is that there is no row returned, therefore the result set is empty
and the scalar result is set to NULL. The reason for not returning a row
could be due to the WHERE OurFileNo = @medicalFileNo clause. Debug into the
code and take a look at Session("selectedFileNumber") especially the type.

Best regards,

Marc Höppner

 

[Cowboy \(Gregory A. Beamer\)]

Only thing I see strange is the following:
myCommand.Parameters.Add("@medicalFileNo", Session("selectedFileNumber") +
"M")

Corrected:
myCommand.Parameters.Add("@medicalFileNo", Session("selectedFileNumber") &
"M")