使用OneToMany的Spring Boot JPA自定义查询

Question

我正在Spring Boot中构建类似Twitter的应用程序。我正在尝试为用户生成时间轴。我对此进行了自定义查询，并将其添加到扩展了repository的{​​{1}}中。当我尝试启动应用程序时，出现以下异常：

CrudRepository<Account, Long>

account_following表是从Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: account_following is not mapped 到@OneToMany的{​​{1}}，如下面的代码所示。我不确定如何将Account放入查询中。

AccountRepository.java

Account

Account.java

account_following

Pom.xml

@Repository
public interface AccountRepository extends CrudRepository<Account, Long> {

    @Query("SELECT t FROM Tweet t, account_following k WHERE k.following_id = t.owner_id AND k.account_ID = :account_ID AND k.following_id IN (SELECT following_ID FROM account_following WHERE account_id = :account_ID) ORDER BY unixdate DESC")
    public List<Tweet> generateTimeline(@Param("account_ID") Long account_ID);

}

表@Entity public class Account implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @Column(unique=true) private String username; @Transient private String password; private String location; private String description; private String website; @OneToMany(cascade = CascadeType.ALL) private List<Account> following; @OneToMany(mappedBy = "owner", cascade = CascadeType.ALL) private List<Tweet> tweets; } 存在于数据库中，如下图所示。我正在使用<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <artifactId>kwetter</artifactId> <groupId>org.springframework</groupId> <version>0.1.0</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.4.RELEASE</version> </parent> <dependencies> <!--Spring Boot--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <type>jar</type> </dependency> <!--JAVAX--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <type>jar</type> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> <type>jar</type> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>5.0.8.RELEASE</version> <scope>test</scope> <type>jar</type> </dependency> <dependency> <groupId>javax</groupId> <artifactId>javaee-web-api</artifactId> <version>7.0</version> <type>jar</type> </dependency> <!--DB--> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>eclipselink</artifactId> <version>2.5.2</version> </dependency> <dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId> <version>2.5.2</version> <scope>provided</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> </dependencies> <properties> <java.version>1.8</java.version> </properties> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> 。

Answer 1

尝试将查询更改为本地查询。

@Repository
public interface AccountRepository extends CrudRepository<Account, Long> {

@Query(value= "SELECT t FROM Tweet t, account_following k WHERE k.following_id = t.owner_id AND k.account_ID = :account_ID AND k.following_id IN (SELECT following_ID FROM account_following WHERE account_id = :account_ID) ORDER BY unixdate DESC",nativeQuery=true)
public List<Tweet> generateTimeline(@Param("account_ID") Long account_ID);
}

由于没有名为 account_following 的实体，因此您会在HQL中看到该错误。

Answer 2

如果是JPQL：

<?xml version="1.0" encoding="UTF-8"?>
<resources>
    <!-- Sign-in Button Colors -->
    <color name="common_signin_btn_dark_text_default">@android:color/white</color>
    <color name="common_signin_btn_dark_text_pressed">@android:color/white</color>
    <color name="common_signin_btn_dark_text_disabled">#FFAAAAAA</color>
    <color name="common_signin_btn_dark_text_focused">@android:color/white</color>
    <color name="common_signin_btn_light_text_default">#FF737373</color>
    <color name="common_signin_btn_light_text_pressed">@android:color/white</color>
    <color name="common_signin_btn_light_text_disabled">#FFAAAAAA</color>
    <color name="common_signin_btn_light_text_focused">#FF737373</color>
    <color name="common_signin_btn_default_background">#FFDD4B39</color>
    <color name="common_action_bar_splitter">#d2d2d2</color>
</resources>

请注意，以上字段必须与类字段相同，而不是数据库中的列名。