如何为具有多个条件和其他关系的子查询编写 jpql 查询

Question

我想通过 JPQL 触发以下查询。我是 JPA 的新手，正在学习 JPQL，但卡在了这个查询中。

SELECT * FROM users
WHERE userid NOT IN (SELECT userid FROM applicants)
AND gender = 'MALE' AND (firstname like '%R%' OR lastname like '%S%');

这里的性别和姓名参数是动态传递的，但这里我保持静态。

我的课程片段是： 这是我的用户类
用户类：

@Table(name = "users")
public class User{

@Id
@GeneratedValue
private long userId;

@Column(unique = true, nullable = false)
private String email;

private String firstName;

private String middleName;

private String lastName;

private String gender;

private Timestamp appliedOn;
}

Applicant 类与 User 类有 OneToOne 关系，join 列是 userid。

申请人类别：

@Entity
@Table(name = "applicants")
public class Applicant{

@Id
private long applicantId;

@OneToOne
@JoinColumn(name = "userId")
private User user;

@ManyToOne
@JoinColumn(name = "subCourseId")
private SubCourse course;

@ManyToOne
@JoinColumn(name = "collegeId")
private College college;
}

Answer 1

您想通过 LEFT JOIN 实现的目标不是：

SELECT * FROM users
LEFT JOIN applicants ON users.userid = applicants.userid
WHERE applicants.userid IS NULL
AND gender = 'MALE' AND (firstname like '%R%' OR lastname like '%S%');

或不在：

SELECT * FROM users
WHERE userid NOT IN (SELECT userid FROM applicants)
AND gender = 'MALE' AND (firstname like '%R%' OR lastname like '%S%');

如果是，您可能应该从那里找到答案。

Answer 2

该 SQL 的 JPQL 查询

SELECT * FROM users
WHERE userid NOT IN (SELECT userid FROM applicants)
AND gender = 'MALE' AND (firstname like '%R%' OR lastname like '%S%');

将是下一个：

String jpql = "SELECT us FROM User us WHERE us.userId NOT IN (SELECT appl.user.userId FROM Applicant appl) AND us.gender = ?1 AND (us.firstName LIKE ?2 OR us.lastName LIKE ?3)";
Query query = entityManager.createQuery(jqpl);
query.setParameter(1, "MALE");
query.setParameter(2, "%R%");
query.setParameter(3, "%S%");
query.getResultList();