Characters

The basic symbols of keywords and operators in the SQL language are single-byte characters that are part of all character sets supported by the IBM® relational database products.

Characters of the language are classified as letters, digits, or special characters.1

A letter is any of the 26 uppercase (A through Z) and 26 lowercase (a through z) letters of the English alphabet. 2

A digit is any of the characters 0 through 9.

A special character is any of the characters listed below:

1 Note that if the SQL statement is encoded as Unicode data, all characters of the statement except for string constants will be converted to single-byte characters prior to processing. Tokens representing string constants may be processed as UTF-16 graphic strings without conversion to single-byte.
2 Letters also include three code points reserved as alphabetic extenders for national languages (#, @, and $ in the United States). These three code points should be avoided because they represent different characters depending on the CCSID.
3 Using the not symbol (¬) and the exclamation point symbol (!) might inhibit code portability between IBM relational database products. Avoid using them because they are variant characters. Instead of ¬= or != use <>. Instead of ¬> or !> use <=. Instead of ¬< or !< use >=.
4 Using the vertical bar (|) character might inhibit code portability between IBM relational database products. Use the CONCAT operator instead of the concatenation operator (||).