Setting a parameter as a list for an IN expression

Question

Whenever I try to set a list as a parameter for use in an IN expression I get an Illegal argument exception. Various posts on the internet seem to indicate that this is poss

Answer 1

Oh, and if you can't use EclipseLink for some reason then here is a method you can use to add the needed bits to your query. Just insert the resulting string into your query where you would put "a.id IN (:ids)".

     /** 
     /* @param field The jpql notation for the field you want to evaluate
     /* @param collection The collection of objects you want to test against
     /* @return Jpql that can be concatenated into a query to test if a feild is in a 
     */
collection of objects
    public String in(String field, List collection) {
        String queryString = new String();
        queryString = queryString.concat(" AND (");
        int size = collection.size();
        for(int i = 0; i > size; i++) {
            queryString = queryString.concat(" "+field+" = '"+collection.get(i)+"'");
            if(i > size-1) {
                queryString = queryString.concat(" OR");
            }
        }
        queryString = queryString.concat(" )");
        return queryString;
    }

Answer 2

IN :ids instead of IN (:ids) - will work.

Answer 3

You can also try this syntax.

static public String generateCollection(List list){
    if(list == null || list.isEmpty())
        return "()";
    String result = "( ";
    for(Iterator it = list.iterator();it.hasNext();){
        Object ob = it.next();
        result += ob.toString();
        if(it.hasNext())
            result += " , ";
    }
    result += " )";
    return result;
}

And put into query, "Select * from Class where field in " + Class.generateCollection(list);