SQL Language elements (characters)
characters, the basic symbols of keywords and operators in SQL language are the single-byte characters that are part of all IBM character sets.
charaters of language are classified as letters, digits or special characters.
A letter is any of the 26 uppercase (A through Z) or 26 lowercase (a through z) letters, plus the three characters $, #, and @, which are included for compability with host database products.
A digit is any of the charaters 0 through 9.
A special character is any of characters listed below:
| Character | Description | Character | Description |
| space or blank | – | minus sign | |
| “ | quotation mark/double quote/double quotation mark | . | period |
| % | percent | / | slash |
| & | ampersand | : | colon |
| ‘ | apostrophe/single quote/singe quotation mark | ; | semicolon |
| ( | left parenthesis | < | less than |
| ) | right parenthesis | = | equals |
| * | asterisk | > | greater than |
| + | plus sign | ? | question mark |
| , | comma | _ | underline/underscore |
| | | vertical bar | ^ | caret |
| ! | exclamation mark | [ | left bracket |
| { | left brace | ] | right bracket |
| } | right brace |
All multi-byte characters are treated as letters, except for the double-byte blank, which is a special character.