Database Integration in Apex

In Apex, the Force.com database is already integrated into the language and runtime environment. There are no object-relational mapping tools or database connection pools to configure. Your Apex code is automatically aware of your database, including all of its objects and fields and the security rules protecting them.

This section examines the five ways the database is exposed in Apex code, which are summarized here:

1. Database records as objects—Database objects are directly represented in Apex as classes. These classes are implicitly imported into your code, so you’re always developing from the latest database schema.

2. Database queries—SOQL is a concise expression of the records to be queried and returned to your programs.

3. Persisting database records—Apex has a built-in Data Manipulation Language (DML), providing verbs that create, update, or delete one or more records in the database.

4. Database triggers—Triggers are code that register interest in a specific action or actions on a database object, such as an insert or delete on the Account object. When this action occurs, the trigger code is executed and can inhibit or enhance the behavior of the database action.

5. Database security in Apex—Normally, Apex code runs in a privileged mode, granting it full access to all the data in the system. Alternatively, you can configure it to run under the same restrictions imposed on the current user, including object and record-level sharing rules.