使用自定义查询（子查询）休眠额外列

Question

@Entity
@Table(name="student")
public class Student
    @Id
    private Integer id;
    private String name;
    private Integer count;

我想分配给

计数

count = SELECT COUNT(*) FROM people

如何使用 JpaRepository 将 result:SELECT COUNT(*) FROM people 分配给整数？

Answer 1

@Formula 帮助您在Hibernate 中创建自己的公式。

@Entity
@Table(name="student")
public class Student
    @Id
    private Integer id;
    private String name;
    @Formula("(SELECT COUNT(*) FROM people)")  // people is table name not entity
    private Integer count;