CODEWITHSUNDEEP
c#sqlwpfselect
J.Do
J.Do

Reputation: 301

Accessing each column of each row on SqlCommand and ExecuteReader

Is there a way to index the reader variable so I can access every single user that's being selected? As this only gets the first record everytime

using (SqlCommand cmd = new SqlCommand("Select * from users", con))
{
    using (SqlDataReader reader = cmd.ExecuteReader())
    {
        while (reader.Read())
        {
            for (int i = 0; i < reader.FieldCount; i++)
            {
                user = new Users(reader["name"].ToString(), reader["image_path"].ToString());

                //MessageBox.Show(reader[1].ToString() + " " + reader[2].ToString());
            }
        }
    }
}

Upvotes: 0

Views: 612

Answers (1)

Marisa
Marisa

Reputation: 792

I think you're misinterpreting the purpose of SqlDataReader.

Each loop through 

while (reader.Read())

will iterate through a row of the returned dataset. If you wish to show each user in a message box, your code ought to look something like the following.

    using (SqlCommand cmd = new SqlCommand("Select * from users", con))
    {
        using (SqlDataReader reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                user = new Users(reader["name"].ToString(), reader["image_path"].ToString());
                MessageBox.Show(user.ToString());
            }
        }
    }

If you wanted to show all the users joined together at the end, you'd want to do something like the following.

    var users = new List<Users>();
    using (SqlCommand cmd = new SqlCommand("Select * from users", con))
    {
        using (SqlDataReader reader = cmd.ExecuteReader())
        {
            while (reader.Read())
            {
                user = new Users(reader["name"].ToString(), reader["image_path"].ToString());
                users.Add(user);
            }
        }
    }

    MessageBox.Show(string.Join(" ", users.Select(x => x.ToString()));

Upvotes: 3

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