Literals are used to represent data in a direct format. Examples of standard types of literals are:

  |integer       - 0, -34, 45, 0X080000000;
  |real          - 0.0, -3.14, 3.23e-23;
  |string        - 'text', 'don''t!';
  |binary string - x'48656C6C6F20776F726C64'
  |date          - DATE'2018-01-19';
  |time          - TIME'15:12:56';
  |timestamp     - TIMESTAMP'2018-01-19 13:32:02';
  |null state    - null

Details about handling the literals for each data type are discussed in the next chapter, Data Types and Subtypes.