Notify if a record already exists in the database before entering, filtering for three conditions. in visual basic and sql server

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Dear good afternoon, I have the following dilemma, I can not do that in my system in visual basic with sql server database, at the moment of wanting to record a new datum in the table, if it exists, warn me of it, fulfilling three conditions at the same time (AND):

  • Do not have the same document number
  • Not belonging to the same area
  • What is not a document of the same year

    • I only find one condition, doing it in the following way, but when I put the 3 I do not find it: 

    MiConexion.Open()
SQL = "SELECT COUNT(*) FROM documentos WHERE numerodocumento = '" & TextBoxNumDoc.Text & "'"

Com = New SqlCommand(SQL, MiConexion)
Rs = Com.ExecuteReader()

Rs.Read()
LabelTomaNumeroDoc.Text = Rs(0)
Rs.Close()
MiConexion.Close()

If LabelTomaNumeroDoc.Text = 0 Then
   Conectar.sqlconectar()
   Conectar.IngresarDoc()
        
    asked by Francisco 21.07.2017 в 21:45
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    1 answer

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    Friend you are doing a step less to extract the value, you lack something like this: 

           If reader.HasRows Then
            Do While reader.Read()
                LabelTomaNumeroDoc.Text = Rs(0)
            Loop
        Else
            LabelTomaNumeroDoc.Text = "0"
        End If

    Try what I add, the error is not reading the result well.

        
    answered by 21.07.2017 в 21:58
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