Background documentationCharacter Set (token) Locate this document in the navigation structure

 

A character set (token) comprises a series of characters that are combined to form a lexical unit. A distinction is made between regular (regular_token) and delimiter (delimiter_token) tokens.

Structure

Syntax Syntax

  1. <token> ::=
      <regular_token>
    | <delimiter_token>
    
    <regular_token> ::=
      <literal>
    | <keyword>
    | <identifier>
    | <parameter_name>
    
    <delimiter_token> ::=
      <vertical_slash>
    | , | . | + | - | * | / | < | > | <> | != | = | <= | >=
    | ~= <!  for computers with ASCII code  !>
    | ~< <!  for computers with ASCII code  !>
    | ~> <!  for computers with ASCII code  !>
    
    <vertical_slash> ::=
      |
End of the code.

Example Example

SELECT * FROM reservation

ALTER TABLE reservation DROP FOREIGN KEY customer_reservation

'Reisen10'

End of the example.
Explanation

Each token can be followed by any number of blanks. Each regular token (regular_token) must be followed by a delimiter token (delimiter_token) or a blank.

Quotation marks within a special identifier are represented by two consecutive quotation marks.

More Information

Identifier (identifier)