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The user can specify expression instead of immediately entered
value of reference to another field.
Syntax: $$(expression text)
An expression can contain: constants, operations and references
to field value as @'field name'.
Operations
Operations '*','/' and unary '-' are acceptable for numeric
operands only.
The '+' operation
|
|
Right operand |
| Left operand |
Integer |
Float |
Date |
Time |
| Integer |
+ |
+ (float) |
Add N days |
Add N seconds |
| Float |
+ (float) |
+ |
N/A |
N/A |
| Date |
add N days |
N/A |
N/A |
N/A |
| Time |
add N seconds |
N/A |
N/A |
N/A |
The '-' operation
|
|
Right operand |
| Left operand |
Integer |
Float |
Date |
Time |
| Integer |
- |
- (float) |
N/A |
N/A |
| Float |
- (float) |
+ |
N/A |
N/A |
| Date |
subtract N days |
N/A |
N/A |
N/A |
| Time |
subtract N seconds |
N/A |
N/A |
N/A |
Notes and limitations:
- '(' and ')' can be used with any acceptable data type.
- Complex nested expressions like $$($$(8-2)-2) are not
acceptable, use '()' instead of. Example: $$((8-2)-2)
Example: 'HireDate' must be greater than 'BirthDate' + 18 years
(265*18 days):
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