What is the meaning of $X{IN, g.data_group, DataGroups}?

Question

I need some help. I want to know what is the meaning of this line

$X{IN, g.data_group, DataGroups}

What is the use of $X in SQL?

Answer 1

The $X is not an SQL feature. It is a jasper reports features where you can dynamically substitute an SQL IN statement when the user provides optional parameters. When the user doesn't supply the parameter, jasper reports substitutes "1 = 1" (which does nothing).

For example, if you have a report with a query looking up Customers by State, you might have a query in a jasper report such as "SELECT * FROM CUSTOMER WHERE $X{IN, state, $P{stateParam}}" which has an optional parameter called stateParam. When the user provides the parameter (say they select two states) jasper will make the query "SELECT * FROM CUSTOMER WHERE STATE IN ('ALABAMA', 'ALASKA')". If the user selects no state they will get all customers "SELECT * FROM CUSTOMER WHERE 1 = 1".

Answer 2

It looks like it supposed to represent in the IN snippets and the NOT IN snippets like:

IN SQL: Give me all users where usersId is 1,2, or 3;

select * from users where usersId in ('1','2','3');

NOT IN SQL: Give me all users where usersId is not 1,2,or 3

select * from users where usersId not in('1','2','3')

parmName should be the name of the report parameter that is either of type Collection or array

colName is I believe the list of ('1','2','3')

$X{IN, colName, paramName}

and

$X{NOTIN, colName, paramName}

Example here: passing SQL "IN" parameter list in jasperreport