$$(expression) specifies numeric, logical (boolean) or date/time expression.

An expression can contain:

• Numeric constants and quoted strings (example: 'null')
• Function calls
• Date or time constants created by $Date or $Time function
• Operations ('+','-','*','/') and comparison operators ('>','>=','<','<=','=', '!=')
• '&' and '|' for AND and OR logicals operators

Operations

Operations '*','/' and unary '-' are acceptable for numeric operands only.

Only comparison operations can be applied to strings.

Logical operations '>','>=','<','<=','=','!=' are acceptable for numeric, date and time operands.

'&' and '|' are acceptable for logical (boolean) operands only. We recommend to use extra '(...)' for complex operands: "((a=1) | (b=2))" instead of "a=1 | b=2".

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	- (int)*	N/A

Notes and limitations

• '(' and ')' can be used with any acceptable data type.
• Logical values have only integer presentation. 1 for 'true' and '0' for 'false'.
• Complex nested expressions like $$($$(8-2)-2) are not acceptable, use '()' instead of: $$((8-2)-2)
• You should use @'name' column reference format in expressions. @number format is not supported for some kind of expressions.
• ^* - approximate number of days between two dates.