insert into multiple tables without knowing the primary key

Hey guys bit of a complication here, I have a create account page and it just inserts data into a mysql db:

    protected void Button1_Click(object sender, EventArgs e)
    {
        OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=root; Password=commando;");
        cn.Open();
        OdbcCommand cmd = new OdbcCommand("INSERT INTO User (Email, FirstName, SecondName, DOB, Location, Aboutme, username, password) VALUES ('" + TextBox1.Text + "', '" + TextBox2.Text + "', '" + TextBox3.Text + "', '" + TextBox4.Text + "', '" + TextBox5.Text + "', '" + TextBox6.Text + "', '" + TextBox7.Text + "', '" + TextBox8.Text + "')", cn);

        cmd.ExecuteNonQuery();
        {
            //e.Authenticated = true;
            Response.Redirect("Login.aspx");
            // Event useradded is true forward to login
        }
    }

}

But here is my problem on the create account page I have added a fileupload control and I would like to upload a image and save the imageurl in the pictures table:

            string filenameDB = Path.GetFileName(FileUploadControl.FileName);
            string fileuploadpath = Server.MapPath("~/userdata/" + theUserId + "/uploadedimage/") + Path.GetFileName(FileUploadControl.FileName);
            FileUploadContr开发者_StackOverflowol.SaveAs(fileuploadpath);
            string fileuploadpaths = ("~/userdata/" + theUserId + "/uploadedimage/") + filenameDB;
            StatusLabel.Text = "Upload status: File uploaded!";


            OdbcCommand cmd = new OdbcCommand("INSERT INTO Pictures VALUES picturepath ='" + fileuploadpaths + "' WHERE UserId = '" + theuserid + "'", cn);
            cmd.ExecuteNonQuery();

The first problem is the sql syntax I need to combine the fileupload with my buttonclick so it would be INSERT INTO two tables User and Pictures but the problem after that is how on earth do I get the userid if the account isnt created yet? AHHH lol

Table structure:

So to sum it up I need to Insert user details into the user table and upload to the project file AND insert the imageUrl into the pictures table (stored like so ~/userdata/2/uploadedimages/bla.jpg) as you can see the pictures table is a 1-1 relationship to the user table so its dependant on the userid which be4 the account is created there is no userid so not sure if there is a way to stagger the code so the user details are inserted first then use a session to retrieve that userid then insert the imageurl into the pictures table?

Or Maybe there is some funky function that some clever person has already came upon this issue or maybe its just a simple sql syntax decombobulator.

P.S I KNOW ABOUT THE SQL INJECTION RISKS, please do not post about this. Thanks guys!

EDIT:

    protected void Button1_Click(object sender, EventArgs e)
    {
        if (FileUpload1.HasFile)
        {
            try
            {
                OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=root; Password=commando;");
cn.Open();

                OdbcCommand cmd = new OdbcCommand("INSERT INTO User (Email, FirstName, SecondName, DOB, Location, Aboutme, username, password) VALUES ('" + TextBox1.Text + "', '" + TextBox2.Text + "', '" + TextBox3.Text + "', '" + TextBox4.Text + "', '" + TextBox5.Text + "', '" + TextBox6.Text + "', '" + TextBox7.Text + "', '" + TextBox8.Text + "')", cn);
                OdbcCommand sc = new OdbcCommand("SELECT LAST_INSERT_ID()", cn);
                //convert LAST INSERT into string theUserId

                string filenameDB = Path.GetFileName(FileUpload1.FileName);
                string fileuploadpath = Server.MapPath("~/userdata/" + theUserId + "/uploadedimage/") + Path.GetFileName(FileUpload1.FileName);
                FileUpload1.SaveAs(fileuploadpath);
                string fileuploadpaths = ("~/userdata/" + theUserId + "/uploadedimage/") + filenameDB;
                Label10.Text = "Upload status: File uploaded!";
                OdbcCommand cm = new OdbcCommand("INSERT INTO Pictures (picturepath, UserId) VALUES ('" + fileuploadpaths + "', " + theUserId + ")", cn);

                cmd.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                Label10.Text = "Upload status: The file could not be uploaded. The following error occured: " + ex.Message;

            }
            //e.Authenticated = true;
            //Response.Redirect("Login.aspx");
            // Event useradded is true forward to login
        }
    }
}

If pictures is 1:1 with users, is it possible to put the picture path in the user table?

If not, MySQL has a last_insert_id() function allowing you to get the last auto-increment value from a table (in this case User) - usually the primary key.

You need to return the new user id from your user insert. From the mysql auto increment docs:

You can retrieve the most recent AUTO_INCREMENT value with the LAST_INSERT_ID() SQL function or the mysql_insert_id() C API function. These functions are connection-specific, so their return values are not affected by another connection which is also performing inserts.

Anyway, you'll need to store this return and pass it into related operations.

I can't see your table structure, but is it as simple as inserting into the User table, retrieving the UserID, preserving the UserID (maybe passing to the upload page on the query string, or using session, etc), and then using that UserID in the Pictures table insert? Here's documentation on how to get the unique ID from an inserted row in MySQL.