Question

How to Customize the NamedQuery in EclipseLink as we do in BirtReport.

Below is Query and Customized Where clause for Birt Report

Is this possible to Customize like this for EclispeLink, your help is much appreciated.

Query

select customernumber from orders

Customized Where Clause for Query

<![CDATA[ 
var parmcount = params["parmorders"].value.length
var whereclause = "";
if( parmcount > 0 ){
    whereclause = " where customernumber in ( ";
}
for( i=0; i < parmcount; i++ ){
    if( i == 0 ){
        whereclause = whereclause + params["parmorders"].value[i];
    }else{
        whereclause = whereclause + " , " + params["parmorders"].value[i];  
    }
}
if( parmcount > 0 ){
    this.queryText = this.queryText + whereclause + " ) ";
}


  ]]> 

Answer 1

From Documentation :

Specifies a static, named query in the Java Persistence query
language. Query names are scoped to the persistence unit. The
NamedQuery annotation can be applied to an entity or mapped superclass

So, NamedQuery can’t be changed at runtime. Also as the number of parameter changes, the query will change. Therefore it isn’t feasible to use NamedQuery for this particular case.

But you can try creating query & appending conditions to it dynamically at runtime based on parameters, just like posted in your code.

entityManager.createQuery(queryText).getResultList();

Also, you can use keyword IN directly & setting the List as parameter to eliminate iteration.

//-- Ignoring code for appending parameters & conditions
String whereCondition = " where customernumber IN (:customerNumbers)";
queryText = queryText + whereCondition;
entityManager.createQuery(queryText).setParameter("customerNumbers", customerNumbersList).getResultList();