IN clause with a composite primary key in JPA criteria

Question

I have a table named group_table in MySQL with only two columns user_group_id and group_id (both of them are of type VARCHAR

Answer 1

You can use a field concatenation approach to solve the problem.

Create a method that returns the two fields you want to search in your DTO/Entity.

  public String getField1Field2Concatenated() {
    return field1+ field2;
  }


List ids = list.stream().map(r -> r.getField1Field2Concatenated()).collect(Collectors.toList());

You can concatenate two fields and do the search.

Select e from Entity e where concat(e.field1,  c.field2) in (:ids)

If any of the fields are not text you can cast

Select e from Entity e where concat(cast(c.field1 as string),  c.field2) in (:ids)