JPQL从POJO中的字符串列表中选择不同的字符串

Question

I have a Java class that has a field which is a list of strings. The elements in the list will vary between objects, but I need to determine a list of distinct values for the field. The Java class looks something like this:

public class POJO implements Serializable {

    @ElementCollection
    private List<String> listOfStrings;

}

JPA creates new table called POJO_listOfStrings, and I could run a SQL query like

SELECT DISTINCT string FROM dbo.POJO_listOfStrings

to get the information I need. I'm at a loss how to do this the correct way with JPQL. Things like "SELECT DISTINCT s FROM POJO.listOfStrings s" do not work. Any help is greatly appreciated.

Answer 1

Distinct on an entity object doesn't work on simple select, you need to specify the element in entity which you want to retrieve distinct.

Similar post in below link should give an insight to it. How do you create a Distinct query in HQL