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***************************************************************************************DML
:= (Data Manipulation Language).A Slash (/) sign at the end of the
code indicates the termination of the
code.***************************************************************************************Partition
Applications
(The process of separating code and placing individual program
units ona server or client)
You can store program units on the server or the clients
depending on you needs.(A program unit stored on an Oracle server
is accessible to all the appl
ications on client nodes).(When the program unit is stored on a
client node, the unit can referenc
e program units on the same client node as well as program unit
on the server).
A program unit is stored on the server when:
-The code is SQL-intensive and contains a large number of DML
and SELECT stateme
nts. (Typically you store database triggers on the server).(Can
be a procedure, a function, a package, or a database trigger).
-The program unit does not need to reference Developer
applications objects or built-in subprograms.
-The program unit is needed by many applications on the server
and client nodes.
-You need to implement system-wide rules.(Such as database
trigger on the Oracle server).
-The program unit needs to use features not available in Oracle
application tool
s.
When you store a program unit on the server:
-The program unit is processed by the PL/SQL engine within the
Oracle server.
-Client/server traffic is reduced.(Program units stored on the
client are transfered to the server for par
sing and execution, this resutls in client/server traffic, to
reduce that traffic place program units on the server).
-The program unit can only reference server-side objects.
(Client-side objects are inaccessible to the program units
stored on thedatabase server).
-Users must have the EXECUTE privilege on the program unit,
unless the user is the owner.
(When a user is not the owner of a program unit, the user needs
the EXECUTE privilege to access and use the program unit sotred on
the database server).
A program unit stored on a client-side:
-Needs a database connection only if SQL calls or server-side
call are made.
-Can reference server-side and Developer objects.
(Server-side objects such as tables, views, sequences, and
packages).(Developer objects such as form variables and form
built-in packages).
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-Sends SQL statements for parsing and execution.
-Is processed by the PL/SQL engine in the client
application.(The Oracle Developer Forms and Procedure Builder are
examples of client
applications processes).
-Can call both server-side and other client-side program
units.
(This includes Developer built-in programs stored on the same
client
node)._______________________________________________________________________Exceptions
1.-Predefined Oracle server exceptions.2.-Non-predefined Oracle
server exceptions.3.-User-defined exceptons.
Predefined exceptions examples:
-NO_DATA_FOUND
-TOO_MANY_ROWS-INVALID_CURSOR-ZERO_DIVIDE-DUP_VAL_ON_INDEX
Non-Predefined exceptions features:
-Unnamed Oracle server exceptions.-20000 exceptions.-Server
raises the exception implicitly.
Trapping Non-predefined Oracle server exceptions:
DECLARE EXCEPTION;PRAGMA_EXCEPTION_INIT (,);--Any further
declarations
BEGIN--Statements
EXCEPTIONSWHEN THEN-Statements for handler
END;
Example use of a User-Defined Exception
DECLARE EXCEPTION;--Any further declarations
BEGIN--StatementsIF SQL%NOTFOUND THEN
RAISE ;END IF;--Statements
EXCEPTIONSWHEN THEN--Statements for handler
END;__________________________________________________________________Trapping
Exceptions
