
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.
<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>::= |
SELECT * FROM reservation
ALTER TABLE reservation DROP FOREIGN KEY customer_reservation
'Reisen10'
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.