A simple 4GL data type can store a single value. The maximum memory used for the storage of a value is set implicitly by the data type declaration or explicitly using indication of size, scale and precision.
|
Indicator |
Description |
Data Types |
|
(size) |
This is the largest amount of bytes that the data type can hold. For CHAR the range can be 1£ size£ 65,534. There is no upper limit for bytes (characters) in the VARCHAR data type, it is limited only by the free memory of the system; the lower limit is 1 as well as in the CHAR data type. The default number of characters is 1 |
CHAR (32) VARCHAR (453) |
|
precision (p) |
This is the number significant of digits that can be used. The significant digits are any digits appearing within the number except for the leading zeros, e.g. number 123,45 has 5 significant digits and its precision is 5. For FLOAT the range is 1 to 14 significant digits. For DECIMAL & MONEY the range is 1 to 32. The default number of digits for DECIMAL and MONEY is 16. |
FLOAT (3) DECIMAL (3) DECIMAL (7,s) MONEY(6,s) |
|
scale (s) |
This is the number of decimal places. There should be 32 or fewer decimal places and the number of decimal places should not exceed the number of significant digits ( scale£precision). The default number of decimal places for MONEY is 2. |
DECIMAL (7, 5) MONEY (6, 2) |
All the above mentioned parameters should be specified using numbers from 1 to 9 and 0, without embedded blank spaces or commas, and without a decimal point.
The simple data types can be subdivided into three large groups: number, time and character.