将根作为函数属性条件查询传递

pass root as function attribute criteria query

我有一个 postgreSQL 自定义函数,它需要一个类型为 "my_entity" 的属性。

在SQL我可以正常调用这个函数:

select my_function(t) from my_entity t;

现在我需要的是使用 CriteriaQuery 调用相同的函数,但是当我尝试时,hibernate 会生成一个 SQL 语句,其中包含 my_table.id 而不是元组本身:

select my_function(my_entity0_.id) from my_entity my_entity0_;

我的代码:

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<MyEntity> cq = cb.createQuery(MyEntity.class);
Root<MyEntity> root = cq.from(MyEntity.class);

Expression<String> myFunction= cb.function("my_function", String.class, root);
cq.select(myFunction);

return em.createQuery(cq).getResultList();

函数:

CREATE OR REPLACE FUNCTION my_function(
      IN "T" my_entity)
RETURNS character varying
LANGUAGE 'plpgsql'

AS $BODY$BEGIN

    ... some logic ...

    RETURN some_calculated_result;

END;$BODY$;

如何将参数正确传递给这个函数?

要使用 CriteriaBuilder 函数传递 my_entity0_.id,您可以尝试以下代码,

Expression<String> myFunction= cb.function("my_function", String.class, root.get("id"));

我只是放弃并创建了一个新函数,它需要 N 个参数而不是 entity/row:

Expression<String> calcSubStatus = cb.function("my_new_function", String.class,
                attr1, attr2, attr3, attr4, attr5, attrN);
CREATE OR REPLACE FUNCTION my_new_function(
      IN "ATTR1" character varying,
      IN "ATTR2" character varying,
      IN "ATTR3" character varying,
      IN "ATTR4" character varying,
      IN "ATTR5" character varying,
      IN "ATTRN" character varying)
RETURNS character varying
LANGUAGE 'plpgsql'

AS $BODY$BEGIN

    ... some logic ...

    RETURN some_calculated_result;

END;$BODY$;