PL/SQL (Procedural Language/Structured Query Language) is Oracle’s proprietary server-based proceduralextension to the SQL database language.The PL/SQL and SQL languages are tightly integrated.PL/SQL supports all the SQL datatypes and the non-value NULL.PL/SQL is a block-structured
language.

Main Features of PL/SQL

• Variables and constants.
  • PL/SQL allows you to declare and use variables and constants in sql
    as well as the procedural statements.
• Cursors
  • A PL/SQL construct called a cursor that
    runs through the tuples of some relation.. There are two kinds of cursors: implicit
    and explicit. PL/SQL implicitly declares a cursor
    for all SQL data manipulation statements, including queries that return only
    one row. For queries that return more than one row, you can explicitly
    declare a cursor to process the rows individually.
• Control Structures
  • Control structures allows to to control conditional, iterative, and
    sequential flow of statements.
  • Conditional Control –IF-THEN-ELSE
  • Iterative
    Control – LOOP-END
LOOP,FOR -LOOP ,WHILE-LOOP
  • Sequential control
• Modularity
  • Successive refinement will reduce a complex problem to a set of simple problems. PL/SQL meets this need with program units. PL/SQL provides the package, procedures and functions, those allows you to group related program items into larger units.
• Data abstraction
  • Data abstraction is achieved in PL/SQL through proper data structure implementations.There are different approaches to achieve this,
  • Collections
  • Records
  • Object Types
• Information hiding
  • Achieved through Packages,procedures,functions etc.
• Error Handling.
  • PL/SQL makes it easy to detect and process predefined and user-defined
    error conditions called exceptions. When an
    error occurs, an exception is raised.