The guidelines for creating identifiers in the CSQL Interpreter are as follows:
< identifier>
:: = < identifier_letter> [ { < other_identifier> } ]
< identifier_letter>
:: = < upper_case_letter>
| < lower_case_letter>
< other_identifier>
:: = < identifier_letter>
| < digit>
| _
| #
< digit>
:: = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
< upper_case_letter>
:: = A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P| Q | R | S | T | U | V | W | X | Y | Z
< lower_case_letter>
:: = a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p| q | r | s | t | u | v | w | x | y | z
Beginning with a Letter
An identifier must begin with a letter. All other special characters except operator characters are allowed. The following are examples of legal identifiers.
a
a_b
ssn#
this_is_an_example_#
Enclosing in Double Quotes, Square Brackets, or Backtick Symbol
Identifiers or a reserved keywords shown as below are not allowed' however, if they are enclosed in in double quotes, square brackets, or backtick symbol, they are allowed as an exception. Especially, the double quotations can be used as a symbol enclosing identifiers when the ansi_quotes parameter is set to yes. If this value is set to no, double quotations are used as a symbol enclosing character strings. The followings are examples of legal identifiers.
" select"
" @lowcost"
" low cost"
" abc" " def"
[position]
Beginning with special characters or numbers
An identifier starting with a special character or a number is not allowed. As an exception, a underline (_) and a sharp symbol (#) are allowed for the first character.
_a
#ack
%nums
2fer
88abs
An identifier containing a space
An identifier that a space within characters is not allowed.
col1 t1
An identifier containing operator special characters
An identifier which contains operator special characters (+, -, *, /, %, ||, !, < , > , =, |, ^, & , ~ ) is not allowed.
col+
col~
col& &