Insert in MySql server with visual C#

Question

I've tried so hard to insert data on MySql server using this code :

private void button1_Click(object sender, EventArgs e)
{
    string con = "datasource=localhost;database=test;port=3307;username=root;password=root";
    MySqlConnection sq = new MySqlConnection(con);
    sq.Open();

    try
    {
        MySqlCommand com1 = new MySqlCommand("Insert into customerinfo(ID) values('" + textBox1.Text + "')", sq);
        com1.ExecuteNonQuery();
        //sq.Open();
    }
    catch (Exception ex)
    {
        MessageBox.Show("please, enter an ID with at most 3 characters !");
    }

    try
    {
        MySqlCommand com2 = new MySqlCommand("Insert into customerinfo(OwnerName) values('" + textBox6.Text + "')", sq);
        com2.ExecuteNonQuery();
        //sq.Open();
    }
    catch (Exception ex)
    {
        MessageBox.Show("please, enter a name with at most 30 characters !");
    }
}

The first try brackets are being excuted well, but for the second try, it throws an exeption! Please help me to know why is this happen?

DO NOT USE STRING CONCATENATION TO GENERATE SQL! ( http://stackoverflow.com/questions/28473476/avoid-string-concatenation-to-create-queries ) it will also help you avoid possible syntax errors. — Dai, Nov 17 '16 at 00:33

score 1 · Answer 1 · answered Nov 17 '16 at 00:47

90% sure that your 'ID' field is required, so you cannot sent just the id... BTW, it seems you're inserting 2 rows, instead a single row with the two values... You may be trying to do:

 MySqlCommand com1 = new MySqlCommand("Insert into customerinfo(ID, OwnerName) values('" + textBox1.Text + "', '" + textBox6.Text + "')", sq);

Some extra tips here:

Open your connection within a using statement, so you ensure the connection memory disposal is handled and closed correctly.
Agreed that adding a dynamic query may result on your application being exposed to SQL injection (a whole topic that you may want to research about). So, just be sure you add a lot of validations on both client side and server side, have a stored procedure, or change this insert to be ORMified.

Hope this helps

Insert in MySql server with visual C#

1 Answers1