Null Values for Data Types
Microsoft Dynamics AX does not support the concept of null values that is available in many other database management systems. A field in Microsoft Dynamics AX always has a type and a value.
For each data type, however, one value is considered null (for example, when the validateField table method is executed).
|
Type |
What is treated as null... |
|---|---|
|
String |
an empty string |
|
Integer |
0 |
|
Real |
0.0 |
|
Date |
dates prior to January 1, 1901 (01-01-1901) |
|
Time |
00:00:00 |
|
Enum |
first entry |
A consequence of this is that when the validateField method checks whether a user has entered a value in a mandatory field, 0 is not accepted in an integer type field, the first entry is not accepted in an enum type field, and so on.
Also, the values that are listed in the previous table yield false in a Boolean comparison.
Variables of type container, and classes and variables of table type can be null in the traditional database management system (DBMS) sense. A table type is null if all its fields have their null value.