Question

我正在使用PostgreSQL数据库＆amp; JPA。这是我的用户表

   CREATE TABLE users
        (
          id integer NOT NULL DEFAULT nextval('userseq'::regclass),
          firstname character varying(64) ,
          middlename character varying(64),
          lastname character varying(64),
          birthdate timestamp with time zone,
         )

    Query query = em
                    .createQuery(
    "SELECT users FROM Users users WHERE user.birthdate =:a")
                            .setParameter("a",18)
                            .setParameter("b",25);
            query.getResultList();

我想让所有年龄在18-25岁之间的用户。请完成我上面的JPA查询

Answer 1

日期运算符缺少JPQL。在SQL中你会写一些类似的东西：

SELECT age(TIMESTAMPTZ '1999-01-01') BETWEEN INTERVAL '18' YEAR AND INTERVAL '25' YEAR;

但据我所知，你不能在JPQL中这样做。 BETWEEN is supported in JPQL，所以我会使用a将日期参数b和java.util.Date转换为java.util.Calendar，然后使用：

SELECT users FROM Users users WHERE user.birthdate BETWEEN :a AND :b

Answer 2

使用Between运算符，首先修复user.birthdate到users.birthdate。

    Calendar cal_1 = Calendar.getInstance();
    cal_1.add(Calendar.YEAR, -18);
    Date a = cal_1.getTime();
    Calendar cal_2 = Calendar.getInstance();
    cal_2.add(Calendar.YEAR, -25);
    Date b = cal_2.getTime();

    query.setParameter("a", a);
    query.setParameter("b", b);

    SELECT users FROM Users users WHERE users.eventsDate BETWEEN :a AND :b

示例：x BETWEEN :min AND :max。参考here

在java中比较Postgresql中的时间戳日期

2 个答案: