Java – HQL, where in indicates an empty list crash

I have an HQL statement like this:

Select cast(ed.employee.employeeID as int) AS emp_id FROM Education AS ed WHERE ed.type.name IN (:typeNames)

But sometimes typenames is empty This can lead to the following:

org.hibernate.hql.ast.QuerySyntaxException: unexpected end of subtree [Select cast(ed.employee.employeeID as int) AS emp_id FROM Education AS ed WHERE ed.type.name IN ()]

What is the solution to accept empty lists?

Solution

One solution I use is to put some virtual values in the list with the input to ensure that it will never be empty Of course, this can only be achieved by selecting virtual values

If your input list is typenamesorig:

List<String> typeNames = new ArrayList<String>(typeNamesOrig);
typeNames.add("valueThatDoesNotExistForSure");
query.setParameterList("typeNames",typeNames);