Database Queries

You’ve seen how data structures in Apex are implicitly defined by the objects in your
database. Force.com provides two query languages to populate these objects with data:
Salesforce Object Query Language (SOQL) and Salesforce Object Search Language
(SOSL). SOSL,  provides unstructured,
full-text search across many objects from a single query.
The focus of this section is SOQL because it is the workhorse of typical business applications.
This section includes subsections on the basics of SOQL, filtering and sorting,
how to query related objects, and how to use SOQL from Apex code.
As you read this section, you can experiment with the sample SOQL queries using the
Force.com IDE’s Schema Explorer. Enter a query in the text box in the upper-left corner
and click the Run Me button.The results appear in the table below the query.