State differences between the following terms.

1. Static cursor and dynamic cursor
2. Implicit cursor and explicit cursor
3. Predefined Oracle server exception and user-defined exception
4. Nonpredefined Oracle server exception and user-defined exception

1. Static cursor and dynamic cursor
? The contents of a static cursor are known at compile time. The cursor object for such an
SQL statement is always based on one SQL statement.
? In a dynamic cursor, a cursor variable is used that can change its value. The variable can
refer to different SQL statements at different times.
2. Implicit cursor and explicit cursor
? You do not declare an implicit cursor. PL/SQL declares, manages, and closes it for every
Data Manipulation Language statement such as INSERT, UPDATE, or DELETE.
? You declare an explicit cursor when you have a SQL statement in a PL/SQL block that
returns more than one row from an underlying table. The rows retrieved by such a
statement into an explicit cursor make up the “active set.” When opened, the cursor points
to the first row in the active set. You can retrieve and work with one row at a time from
the active set. With every fetch of a row, the pointer moves to the next row. The cursor
returns the current row it is pointing to.
3. Predefined Oracle server exception and user-defined exception
? Predefined Oracle server exceptions are exceptions that are named by PL/SQL and are
raised implicitly when a PL/SQL or DBMS error occurs. There are about 20 such
exceptions. They have a name and associated error number.
? User-defined exceptions are exceptions that are declared in the declaration section and
raised by the user explicitly. The user decides which abnormal condition is an exception.
The Oracle server does not consider these conditions to be errors.
4. Nonpredefined Oracle server exception and user-defined exception
? Nonpredefined Oracle server exceptions are standard Oracle server errors that are not
named by the system. They can be declared in the declaration section but are raised
implicitly by the server. These exceptions do not have name, but have associated error
number.
? User-defined exceptions are exceptions that are declared in the declaration section and
raised by the user explicitly. The user decides which abnormal condition is an exception.
The Oracle server does not consider these conditions to be errors.