PL/SQL

 PL/SQL (PROCEDURAL LANGUAGE/STRUCTURED QUERY LANGUAGE)

PL/SQL is a language that enables developers to create procedures, functions that combine sql with procedural statements.

PL/SQL block has three parts in it.

1. Declaration       All objects of the block are declared.

2. Execution          The objects are defined to manipulate data.

3. Exception          Error handling logic.

==>Declaration part is optional when we do not declare any objects

==>Exception part is also optional if we are not handling any exceptions.

==>But the Execution part is must in a PL/SQL Program and it starts with BEGIN and ends with END.

Execution:

========

To Execute the PL/SQL Program follow the syntax as

@<file_name>

or

start<file_name>

==>To Display the Result, give the command as follows

set serveroutput on

------------------------------------------------------------------------------

begin

                dbms_output.put_line('Welcome');

end;

/

------------------------------------------------------------------------------

declare

                city varchar2(10):='Hyderabad';

                dt date:='24/APR/2012';

begin

                dbms_output.put_line('welcome to '||city);

                dbms_output.put_line('todays date is '||dt);

end;

/

------------------------------------------------------------------------------

declare

                n1 number(10):=100;

                n2 number(10):=200;

begin

                dbms_output.put_line('Sum is: '||n1+n2);

end;

/

------------------------------------------------------------------------------

DECLARE

                name1 varchar2(20):='&name1';

                name2 varchar2(20);

BEGIN

                name2:='&name2';

if name1=name2 then

                    dbms_output.put_line('Both are equal');

                else

                    dbms_output.put_line('Not Equal');

                end if;

END;

/

------------------------------------------------------------------------------

declare

                n1 real:=10.50;

                n2 real:=20.35;

                n3 real;

begin

                n3:=n1+n2;

dbms_output.put_line ('The N1 value is => '||n1);

dbms_output.put_line ('The N2 value is => '||n2);

dbms_output.put_line ('The N3 value is => '||n3);

end;

/

------------------------------------------------------------------------------

DECLARE

   bv boolean:=true;

BEGIN

   If (bv=true) Then

       dbms_output.put_line('True');

   Else

       dbms_output.put_line('False');

   End If;

END;