JPA命名查询使用OR和Null运算符给出空结果

Question

Written named query

  @NamedQuery(name = PKGruppeBE.FIND_ALL_GROUP_SPECIFIC, query = "SELECT e FROM PKGruppeBE e 
  WHERE 
  (e.tkgroup.id = ?1 OR e.tkgroup IS NULL )")

But query is not giving correct result,

if there is a match , and tkgroup is null giving only matched results,

if there is no match , and tkgroup is null giving empty result.

My requirement is I have to get all results where tkgroup is null and if are there any matches those results also.

Answer 1

试试这是否有效

SELECT e FROM PKGruppeBE e left join e.tkgroup gr WHERE gr.id = ?1 OR gr IS NULL