Passing sql query result to textbox

Question

I'm using PostgreSQL DB, and I want to make a data displayer for my friend who doesn't know SQL but sometimes he need to get some information.

I want to write a Windows Forms application which should allow him to type some client id and in result give him some data about this client.

I wrote something like this (below) and I am stuck - after clicking a button I want to pass the answer of my query to a textBox and I can't, tried many solutions. None worked. Anyone can help ?

    private void btShowData_Click(object sender, EventArgs e)
    {
        NpgsqlConnection conn = new NpgsqlConnection("Server=someServer;Port=1234;User ID=some_user;Password=123456;Database=someDataBase;");
        conn.Open();

        NpgsqlCommand answer1 = new NpgsqlCommand("SELECT column1 FROM table1 WHERE id = :userId", conn);
        answer1.Parameters.Add(new NpgsqlParameter("userId", NpgsqlTypes.NpgsqlDbType.Integer));
        answer1.Parameters[0].Value = tbId.Text;
   // HERE IS MY PROBLEM - How to pass the answer1 result to the textbox
    }

Soner Gönül · Accepted Answer · 2014-03-15 14:34:33Z

1

I'm not too much familiar with PostgresSQL but I think you can use ExecuteScalar method. It returns first column of the first row as an object.

If your column1 is character type, you can use it like;

...
answer1.Parameters[0].Value = tbId.Text;
string s = (string)answer1.ExecuteScalar();
TextBox1.Text = s;

edited Mar 15, 2014 at 14:34

answered Mar 15, 2014 at 14:28

Soner Gönül

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Comments

Sudhakar Tillapudi · Accepted Answer · 2014-03-15 14:28:26Z

1

Solution 1:

NpgsqlDataReader reader = answer1.ExecuteReader();
if(reader.Read())
{
    yourTextBox.Text = reader["column1"].ToString();
}

Solution 2:

yourTextBox.Text = answer1.ExecuteScalar().ToString();

answered Mar 15, 2014 at 14:28

Sudhakar Tillapudi

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Comments

Subtractive · Accepted Answer · 2014-03-15 14:28:59Z

-1

To pass text to a TextBox all you need to do is write:

TextBoxName.Text = yourVariable.ToString();

answered Mar 15, 2014 at 14:28

Subtractive

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2 Comments

Soner Gönül Over a year ago

What is yourVariable? o.O

Subtractive Over a year ago

Sorry for beeing unclear, answer1.ToString() adds the variables value you your textbox. Using the above mentioned method ExecuteScalar().Tostring() does what you are asking. :)

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