在JPA Criteria API中使用array_position吗？

Question

我正在使用springjpa和postgresql，我的数据库中有一个字段为bitint数组类型，而在Java中，这是一个Long值。

我正在使用spring jpa CriteriaBuilder＆Specification来创建数组位置函数：

private Predicate toPredicate(String propName, Query q, Root<T> root, CriteriaBuilder cb) {
    ...
    return cb.isNotNull(cb.function("array_position", Integer.class,
                            xx expression,
                            cb.literal(q.value)));  // q.value is a long type value
}

并且当我执行查询时出错：

Hibernate: 
    select
        distinct ruletemp0_.id as id1_119_,
        ruletemp0_.applicant as applican2_119_,
        ruletemp0_.approver as approver3_119_,
        ruletemp0_.devices as devices4_119_,
        ruletemp0_.end_time as end_time5_119_,
        ruletemp0_.execution_id as executio6_119_,
        ruletemp0_.execution_type as executio7_119_,
        ruletemp0_.extra as extra8_119_,
        ruletemp0_.rule_id as rule_id9_119_,
        ruletemp0_.start_time as start_t10_119_,
        ruletemp0_.state as state11_119_,
        ruletemp0_.user_id as user_id12_119_ 
    from
        tbl_ruletemp ruletemp0_ 
    where
        array_position(ruletemp0_.user_id, 1) is not null 
        or array_position(ruletemp0_.user_id, 2) is not null
2019-10-30 10:44:42.230 [WARN ] [main] [org.hibernate.engine.jdbc.spi.SqlExceptionHelper::logExceptions] SQL Error: 0, SQLState: 42883
2019-10-30 10:44:42.230 [ERROR] [main] [org.hibernate.engine.jdbc.spi.SqlExceptionHelper::logExceptions] ERROR: function array_position(bigint[], integer) does not exist
  建议：No function matches the given name and argument types. You might need to add explicit type casts.

似乎jpa无法识别我的Long类型值，我尝试使用：

BigInteger bigInteger = new BigInteger(String.valueOf(q.value));
return cb.isNotNull(cb.function("array_position", Integer.class,
                            toExpression(propName, root),
                            cb.literal(bigInteger)));                    

仍然错误。如果我直接在pg中执行SQL查询：

select * from tbl_ruletemp t where array_position(t.user_id, cast(1 as BIGINT)) is not null;

将起作用。

和想法？

Answer 1

您可以使用条件构建器创建cast表达式，但是可能没有必要。不要将数字用作文字，而应将其作为参数传递。

ParameterExpression<BigInteger> pid = cb.parameter(BigInteger.class, "pid");
return cb.isNotNull(cb.function("array_position", Integer.class,
                            toExpression(propName, root),
                            pid));

然后像往常一样简单地绑定参数。并且由于您使用的是数组，所以最好使用arrayoverlap而不是链接array_position调用和or表达式。