So I'm currently working on a program which consist of registration page and login page using visual basic and access database. What do I need to do to make an error so that the program said if user already exist when they entered a similar data into the system?. currently i managed to let user input the data inside access through visual basic but cannot find a solution on how to compare the input and the data that already exist in the database.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
