How to write in clause on where condition for a sql

[das.sujit1]

I have a query like this 

SELECT * FROM CATEGORY  CAT WHERE   CAT.CAT_CAT_NO  =$P{employerRefNumber} 

Now I want to pass in cluse in where condition like

SELECT * FROM CATEGORY  CAT WHERE   CAT.CAT_CAT_NO  in ($P{employerRefNumber} )

value of employerRefNumber should be 'C001','C002' like this.

Kindly guide me proper sysntex of this query in jasper report

 

 

[gustavofarias]

https://community.jaspersoft.com/documentation/tibco-jaspersoft-studio-user-guide/v60/using-parameters-queries#jss-user-parameters_221620694_1025261

[bigalex]

$X{IN,CAT.CAT_CAT_NO,employerRefNumber}    

$P{employerRefNumber} must be collection class