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:
| space or blank | - | minus sign | |
| " | quotation mark or double-quote or double quotation mark | . | period |
| % | percent | / | slash |
| & | ampersand | : | colon |
| ' | apostrophe or single quote or single quotation mark | ; | semicolon |
| ( | left parenthesis | < | less than |
| ) | right parenthesis | = | equals |
| * | asterisk | > | greater than |
| + | plus sign | ? | question mark |
| , | comma | _ | underline or underscore |
| | | vertical bar4 | ‸ | caret |
| ! | exclamation mark3 | [ | left bracket |
| { | left brace | ] | right bracket |
| } | right brace | ¬ | not 3 |