In PL/SQL, statements are grouped into units called Blocks. PL/SQL blocks can include constants, variables, SQL statements, loops, conditional statements, exception handling. Blocks can also build a procedure, a function or a package.
Broadly, PL/SQL blocks are two types :
(i) Anonymous blocks : PL/SQL blocks without header are known as anonymous blocks. These blocks do not form the body of a procedure, function or triggers.
Example :
DECLARE
num NUMBER(2);
sq NUMBER(3);
BEGIN
num:= &Number1;
sq := num*num;
DBMS_OUTPUT.PUT_LINE(‘Square:’ ||sq);
END;
(ii) Named blocks : PL/SQL blocks having header or labels are known as Named blocks. Named blocks can either be subprograms (procedures, functions, packages) or Triggers.
Example :
FUNCTION sqr (num IN NUMBER)
RETURN NUMBER is sq NUMBER(2);
BEGIN
sq:= num*num;
RETURN sq;
END;
