Constant

A constant as the name implies is a value that is not variable. It cannot be changed after it has been assigned to. By virtue of the fact that it cannot be modified a constant cannot be declared without also being initialised.

PL/SQL Example

DECLARE
  -- c_someConstant CONSTANT NUMBER; -- ILLEGAL since no initial value has been supplied.
  c_report_lines CONSTANT NUMBER := 80;  -- Define a numeric constant
BEGIN
  dbms_output.put_line('Report has '||c_report_lines||' lines');
END;
/

Also see

• Variable

Glossary of Terms
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