Using Literals in Expressions
The following literals are valid expressions:
'J. J. Jones'
'Hendersonville'
'17-Aug-1998 10:00'
1209
7.77
4GL recognizes two basic types of literals, string and numeric. In addition, it recognizes the special literal NULL.
• String literals include character strings, date, and hexadecimal strings.
• Character literals are represented by a sequence of characters enclosed in single quotation marks. Within a string literal, you can indicate a literal single quote by typing two single quotes (for example, 'J. J. Jones''s').
• Application constants are represented by the constant name preceded by a colon (for example, :help_opt).
• Date literals must be specified as strings (for example, '11/15/98') but you can manipulate dates in date arithmetic operations.
• Hexadecimal numbers are represented by a special form of string literal. This is a string of hexadecimal digits (0 through 9 and A through F) preceded by the letter X and enclosed in single quotes. For example:
X'10A665B'
X'00FF'
• Numeric literals include integers and floating-point numbers. You can specify literals of type money as strings or numbers (for example, '$10.50' or 10.5).
How You Use Hexadecimal for Nonprintable Characters
You can represent printable characters literally as strings. To specify a nonprintable character, use a hexadecimal literal of the form:
X'nn{nn}'
In this form, each character is represented as two hexadecimal digits (nn). For example, the following statement inserts the string "XYZcarriage return" into "col1" and a numeric into "col2" of "table1":
insert into table1 (col1, col2)
values (X'58595A0D', 500);
The hexadecimal literal is translated to the corresponding character value.