Shulou(Shulou.com)06/01 Report--

When developing ADF applications, the system default primary key is unique, but the error message provided by the system is too ugly, so we can customize the error where the primary key is not unique.

In addition to the unique primary key, sometimes we need to combine other fields to make unique, such as a certain time, place, and character combination into the only data, we have to use candidate keys to constrain EO.

Here is the illustration:

End.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.