MySQL C# Query trouble - Updating table

MySQL C# Query trouble - Updating table

I'am having trouble with this function I'm creating to Update my database.
The Update faculty member seems to work perfectly while the Updating of
the person tables does not . I'm presuming that the MySQL Query isn't
correct for updating the person table.
Additional INFO: My code is hooked to an GUI mock as of right now for
testing purposes . the Update string with @Id.. its just to select which
ID I wish to change..
public static void Update(string update,string fName, string lName, string
DOB, string postCode, string address, string phoneNumber,
bool isTenured, string
qualifications, string
previousEmployment)
{
MySqlConnection conn;
MySqlCommand cmd;
string sql = "UPDATE person SET firstName = @FirstName ,
lastName = @LastName, DOB = @DOB, phoneNumber =
@PhoneNumber, address = @Address, postCode = @PostCode
WHERE ID =@Id;";
GetConnection(out conn, out cmd, sql);
try
{
cmd.Parameters.AddWithValue("@Id", update);
cmd.Parameters.AddWithValue("@FirstName", fName);
cmd.Parameters.AddWithValue("@LastName", lName);
cmd.Parameters.AddWithValue("@DOB", DOB);
cmd.Parameters.AddWithValue("@PhoneNumber", phoneNumber);
cmd.Parameters.AddWithValue("@Address", address);
cmd.Parameters.AddWithValue("@PostCode", postCode);
long id = (long)cmd.LastInsertedId;
sql = "UPDATE facultymember SET isTenured =
@IsTenured, qualifications = @Qualifications,
previousEmployment = @PreviousEmployment WHERE
Person_personID=@Id";
cmd = new MySqlCommand(sql, conn);
cmd.Parameters.AddWithValue("@IsTenured", isTenured);
cmd.Parameters.AddWithValue("@Qualifications",
qualifications);
cmd.Parameters.AddWithValue("@PreviousEmployment",
previousEmployment);
cmd.ExecuteNonQuery();
}
catch (NullReferenceException nre)
{
MessageBox.Show(nre.Message);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
finally
{
try
{
MessageBox.Show("Updated");
cmd.Connection.Close();
conn.Close();
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
}