Types of blocks in PL/SQL

Types of blocks in PL/SQL:
A PL/SQL program can be written in various types of blocks, they are 
1) Anonymous block:

• The block having no name.
• They are declared at the point in an application, where they are to be executed and are passed to PL/SQL engine for execution at runtime.
• It cannot be called.
• There are used in D2K form.

SQL>DECLARE
         BEGIN
               NULL;
         EXCEPTION
         WHEN OTHERS THEN
               NULL;
         END;

2) Named Block:

• The block having name and they have all the features as specified for the anonymous blocks.
• Named blocks help in associating with the scope and resolution of variables in different blocks.
• They give the specifications of the named spaces as provided in high level OOPs languages like C++ and JAVA.
• Named blocks are conveniences for variable management.

 SQL><<FirstBlock>>          DECLARE
          BEGIN
                 NULL;
          EXCEPTION
          WHEN OTHERS THEN
                 NULL;
          END FirstBlock;

• Named blocks make the PL/SQL blocks more clear and readable.
• Named blocks increase the clarity of programming when we attempt the nesting process, and control structures.

3) Sup-Programmed blocks:

• These are named PL/SQL blocks that can take parameters and can be invoked with in the other anonymous or sub-programmed PL/SQL blocks.
• These blocks are either is declared as procedures or functions.
• A procedure block is used for performing an action, and a functional block is used for performing calculation.
• These sub-programs provides modularity and reusability.