The ##OB_OPTIONSELECT_ALL macro accepts two comma-separated arguments in this format:
##OB_OPTIONSELECT_ALL{(arg1,arg2)}
The arguments return an expression that always affirms the current SQL expression if they are equivalent. The most obvious use of this macro is in creating an <ALL> option in a drop-down list runtime parameter.
For example, this expression is expanded using the following logic:
select * from some.dbtable
where scope = ##OB_OPTIONSELECT_ALL{(@{param}, 0)}
If @{param} = 0 then the query is expanded to:
select * from some.dbtable
where scope = @{param} OR 1=1
Else, if @{param} <> 0 then the query is expanded to:
select * from some.dbtable
where scope = @{param}
In the Insert Macro menu, this macro is listed as Option Select All.