Error getting "database not selected" when trying to query the database

Question

I am a student in a professional high school, and I'm still new to programming, I have the task of creating an application using C #, and I had a problem with joining three tables to display on a datagridview. I tried the query on mySql, it works fine, but when I applied it in my C # line of code, it didn’t work, it shows “no database selected”, can anyone help me with this, here is my full code

string constring = "datasource=localhost;port=3306;username=root;password=root";
        MySqlConnection conDataBase = new MySqlConnection(constring);
        MySqlCommand cmdDataBase = new MySqlCommand("select book_detail.id_bookdetail, location.location_id, location.location_name, book.book_id, book.title from location inner join book_detail on location.location_id = book_detail.location_id inner join book on book_detail.book_id = book.book_id; ", conDataBase);
        try
        {
            MySqlDataAdapter sda = new MySqlDataAdapter();
            sda.SelectCommand = cmdDataBase;
            DataTable dbdataset = new DataTable();
            sda.Fill(dbdataset);
            BindingSource bSource = new BindingSource();

            bSource.DataSource = dbdataset;
            transfer_view.DataSource = bSource;
            sda.Update(dbdataset);
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }

Answer 1

The connection string must contain the database name:

Server=myServerAddress;Database=myDataBase;Uid=myUsername;Pwd=myPassword;
                       ^^^^^^^^^^^^^^^^^^^

(Port 3306 is the default port of MySql)

Ref. MySQL Connection Strings

Answer 2

" mydbname"

, ,

"select database()", db