int iCustomerId = GetMaxCustomerId();
SqlCommand cmd = _conn.CreateCommand();
cmd.CommandText = string.Format("update Customers set CustomerName='updated CustomerName',
Address = 'updated Address',Phone = "updated Phone" where CustomerId ={0}",iCustomerId);
运行的时候总是提示

string.Format("update Customers set CustomerName='updated CustomerName',Address = 'updated Address',Phone = "+updatedPhone+" where CustomerId ={0}",iCustomerId);
你换行的时候要用加号。

string.Format( 去掉，什么都用这个。你Y的胡用函数