MySQL 至 JPA/JPQL 查询

Question

我尝试将我的 Mysql 查询转换为 JPQL，但我不知道哪个工具可以在不编译的情况下用于 eclipse。

我的logg没有告诉我错误在哪里，所以我找不到语法错误的地方。

这是我的查询："SELECT COUNT(*) FROM computer c LEFT JOIN company comp ON c.company_id = comp.id where c.name like ?"

我这样试过： "SELECT COUNT(*) FROM computer c LEFT JOIN company comp ON c.company_id = comp.id where c.name like :filter"

但是没用。

计算机 class：

@Entity
@Table(name="computer")
//@NamedQuery(name="computer.rowsWithFilter", query="select count(c.id) from computer c left join company comp on c.company_id = comp.id where c.name like :filter") 
public class Computer {

    @Id @GeneratedValue
    private long id;

    @Column(name="name")
    private String name;

    @Column(name="introduced")
    private LocalDate introduced;

    @Column(name="discontinued")
    private LocalDate discontinued;

    @ManyToOne
    private Company company;

公司class：

@实体 @Table(姓名="company")

public class Company {

    @Id
    @GeneratedValue
    private long id;

    @Column(name="name")
    private String name;

感谢您的帮助！

Answer 1

试试这个：

SELECT COUNT(c.id) 
FROM computer c 
LEFT JOIN c.company comp
where c.name like :filter

MySQL 至 JPA/JPQL 查询

MySQL to JPA/JPQL query

java

eclipse

jpa

jpql