Retrieve SqlCommand as string

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Retrieve SqlCommand as string

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#1 by (1 votes)

1

I need to retrieve a DB information with a select and compare it to what the user is typing if they are different information, I allow the insert. If the comparison is the same I do not insert and display error message.

Here's what I'm trying to do:

    SqlCommand cmd = new SqlCommand(" SELECT Porta FROM Equipamento WHERE Porta = txtPorta.Text", conn);

    string portacadastrada = cmd.ToString();

    string portatentativa = Convert.ToString(txtPorta.Text);

    if (portacadastrada == portatentativa)
    {
        ShowMessage("Porta já cadastrada.");

    }

c# .net

asked by anonymous 05.07.2017 / 16:51

1 answer

Classes within classes (Python / Django) Take a network file in java

score 1 · Accepted Answer

SqlCommand is to execute commands like Insert, Delete and Update to retrieve information you can do in the following way:

//Pega a porta digitada pelo usuario
var portaDigitada = txtPorta.Text;
//Monta o comando usando DataAdapter
var comando = new SqlDataAdapter("SELECT Porta FROM Equipamento WHERE Porta 
= @porta", conn);
comando.SelectCommand.Parameters.AddWithValue("@porta", portaDigitada);
//Cria um DataTable que vai armazenar o resultado do BD
        var dt = new DataTable();
//Preenche o datatable com o resultado do bd
        comando.Fill(dt);
//Pega o Valor que esta querendo, Onde Rows[0] é o numero da linha, Considerando que esta comando traga somente uma
        string portacadastrada = dt.Rows[0]["Porta"];