Getting started with Oracle PL/SQL

PL/SQL stands for Procedural Language / Structured Query Language which is extension of SQL.
PL/SQL offers set of procedural commands/statements ,organized in blocks. Hence called block-structured language.

Oracle uses PL/SQL engine to process  PL/SQL statements.

Simple PL/SQL block:

PL/SQL block consists of 3 sections.

1.Declaration section. (Optional)
   Keywords DECLARE
2.Executable section . (Must)
   Keywords BEGIN, END
3.Exception Handling section (Good to have)
    Keywords EXCEPTION

       DECLARE

              –- Declare variables,constants and other code elements

       BEGIN

              –- Program execution. Write sql code.

             

       EXCEPTION

              -- Exception Handling

       END;

Here is simple PL/SQL block that displays a message.

       DECLARE 

              show_message VARCHAR2 (100) := 'Hello World!';

       BEGIN 

              DBMS_OUTPUT.put_line (show_message);

       EXCEPTION 

       WHEN OTHERS

              THEN   DBMS_OUTPUT.put_line (SQLERRM);

       END;