How do I set a parameter to a list of values in a BIRT report?

Question

I have a DataSet with a query like this:

select s.name, w.week_ending, w.sales 
from store s, weekly_sales_summary w 
where s.id=w.store_id and s.id = ?
         


        

Answer 1

I created a more general solution, which handles optional/required parameters behaviour too. When parameter is not required and user doesn't select any value, the IN-clause gets disabled. It also allows the user to select both real values and null value.

In report initialize script I add this code:

/** Fullfill IN-clause in a data set query,
 *  using a List box report parameter.
 *  Placeholder must be the parentheses after IN keyword with wathever you want inside.
 *  If required is false then the whole IN-clause in the query 
 *  must be surrounded by parentheses.
 *  dataType and required refers to the parameter, they must be passed, 
 *  but should be better to find a way to retrieve them inside this function
 *  (given parameter name).
 */
function fulfillInClause(dataSet, placeholder, param, dataType, required) {

    if (dataSet.queryText.indexOf(placeholder)>=0) {

        var paramValue = params[param].value;
        var emptyParam = (paramValue==null || paramValue.length<=0);

        //build the list of possible values
        //  paramValue==null check in ternary operators 
        //  will prevent exceptions when user doesn't select any value
        //  (it will not affect the query if param is optional, 
        //  while we will never arrive here if it is required)
        var replacement = " (";
        if (dataType == "string")
            replacement += (emptyParam ? "''" : createList(paramValue, ",", "'", "varchar(10)") );
        else if (dataType == "integer")
            replacement += (emptyParam ? "0"  : createList(paramValue, ",", "" , "int"        ) );
        else
            //TODO implement more cases
            return;
        replacement += ") ";

        //if param is not required and user doesn't select any value for it
        //then nullify the IN clause with an always-true clause
        if (!required && emptyParam)
            replacement += " or 0=0 ";

        //put replacement in the query
        dataSet.queryText = dataSet.queryText.replace( placeholder, replacement );
        //DEBUG
        params["debug" + dataSet.name + "Query"]=dataSet.queryText;        
    }
}

/** Create a string list of array values,
 *  separated by separator and each of them surrounded by a pair surrounders
 */
function createList(array, separator, surrounder, sqlDataType){
    var result = "";

    for(var i=0; i0)
            result += separator;

        if(array[i]!=null)
            result += surrounder + array[i] + surrounder;
        else
            result += "cast(null as " + sqlDataType + ")";
    }
    return result;
}

Usage example

In dataset query put your special IN-clause:

select F1, F2
from T1 
where F3='Bubi'
  and ( F4 in (''/*?customers*/) )

In beforeOpen script of the dataset with the IN-clause write:

fulfillInClause(this, "(''/*?customers*/)", "customers", "string", false);

Note that I used a placeholder which allows the query to run also before the replacement (eg. it has quotes as F4 is a varchar). You can build a placeholder that fits your case.