Compound Expressions

A compound expression specifies a combination of other expressions.

compound_expression::=

Description of the illustration compound_expression.gif

You can use any built-in function as an expression ("Function Expressions "). However, in a compound expression, some combinations of functions are inappropriate and are rejected. For example, the LENGTH function is inappropriate within an aggregate function.

The PRIOR operator is used in CONNECT BY clauses of hierarchical queries.

Some valid compound expressions are:

('CLARK' || 'SMITH') 
LENGTH('MOOSE') * 57 
SQRT(144) + 72 
my_fun(TO_CHAR(sysdate,'DD-MMM-YY'))