When you reference an object name in a request, you may need to qualify the name. The topics that follow explain the rules for use of qualified and unqualified object names.
The following example shows unqualified, qualified and a fully qualified name references in a SELECT statement that accesses the Employee table in the personnel database:
SELECT Name, DeptNo, JobTitle FROM Personnel.Employee WHERE Personnel.Employee.DeptNo = 100 ;
For more information about the default database, see “The Default Database.”