的EclipseLink MySQL的左連接錯誤：未知列

Question

我有這個數據模型：

AbstractEntity (abstract, @MappedSuperClass) 
    | 
    +---- Subject (abstract, @Entity, joined) 
    |  | 
    |  +---- Person (@Entity) 
    |  | 
    |  +---- ... 
    | 
    +---- Metadata (abstract, @Entity, joined) 
      | 
      +---- ... 

實現了：

@MappedSuperclass 
public abstract class AbstractEntity implements Serializable 
{ 
    private static final long serialVersionUID = 1L; 

    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    @Column(nullable = false) 
    protected Long id; 

    @Version 
    protected Integer version; 

    ... 
} 

@Entity 
@Inheritance(strategy = InheritanceType.JOINED) 
public abstract class Subject extends AbstractEntity 
{ 
    @ManyToOne 
    @JoinColumn(name = "PROFILE_ID") 
    protected Profile profile; 

    @ElementCollection 
    @CollectionTable(name = "SUBJECT_RIGHTS", joinColumns = @JoinColumn(name = "OWNER_ID")) 
    @Column(name = "CODE") 
    protected Set<String> rightSet = new HashSet<String>(); 

    @Transient 
    public abstract String getTitle(); 

    ... 
} 

@Entity 
public class Person extends AbstractEntity 
{ 
    @NotBlank 
    private String firstName; 

    @NotBlank 
    private String lastName; 

    ... 
} 

@Entity 
@Inheritance(strategy = InheritanceType.JOINED) 
public abstract class Metadata extends AbstractEntity 
{ 
    @ElementCollection 
    @CollectionTable(name = "METADATA_PREFERENCE", joinColumns = @JoinColumn(name = "METADATA_ID")) 
    @MapKeyJoinColumn(name = "PERSON_ID", nullable = false) 
    @Enumerated(EnumType.STRING) 
    @Column(name = "PREFERENCE", nullable = false) 
    protected Map<Person, PreferenceType> preferenceMap = new LinkedHashMap<Person, PreferenceType>(); 

    ... 
} 

，我試圖執行這個查詢：

select m.id from Metadata m left join m.preferenceMap p [where not important] 

和eclipselink生成此SQL：

SELECT t0.ID FROM METADATA t0 LEFT OUTER JOIN METADATA_PREFERENCE t3 ON ((t3.METADATA_ID = t0.ID) AND (t1.ID = t3.PERSON_ID)), PERSON t2, SUBJECT t1 [where not important] 

但此查詢產生的異常：

com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 't1.ID' in 'on clause' 

我知道MySQL的加入優先級，所以我需要的EclipseLink以這種方式重寫查詢：

SELECT t0.ID FROM (METADATA t0, SUBJECT t1) LEFT OUTER JOIN METADATA_PREFERENCE t3 ON ((t3.METADATA_ID = t0.ID) AND (t1.ID = t3.PERSON_ID)), PERSON t2 [where not important] 

如何做到這一點？ ??

但是我使用：

mysql: 
+-------------------------+------------------------------+ 
| Variable_name   | Value      | 
+-------------------------+------------------------------+ 
| innodb_version   | 1.1.7      | 
| protocol_version  | 10       | 
| slave_type_conversions |        | 
| version     | 5.5.13-log     | 
| version_comment   | MySQL Community Server (GPL) | 
| version_compile_machine | x86       | 
| version_compile_os  | Win64      | 
+-------------------------+------------------------------+ 

eclipselink: 
Eclipse Persistence Services - 2.4.1.v20121003-ad44345 

，這是persistence.xml中

<?xml version="1.0" encoding="UTF-8"?> 
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> 
    <persistence-unit name="prime" transaction-type="JTA"> 
     <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> 
     <jta-data-source>jdbc/prime</jta-data-source> 
     <exclude-unlisted-classes>false</exclude-unlisted-classes> 
     <properties> 
      <property name="eclipselink.target-database" value="MySQL"/> 
      <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/> 
      <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/prime"/> 
      <property name="javax.persistence.jdbc.user" value="root"/> 
      <property name="javax.persistence.jdbc.password" value="password"/> 
     </properties> 
    </persistence-unit> 
</persistence> 

Answer 1

eclipselink 2.5.0（jpa 2.1）解決了這個錯誤。

Answer 2

它似乎越來越被加入到複雜的地圖ElementCollection混淆。似乎是一個錯誤，請記錄該錯誤併爲其投票，並確保您使用的是最新的修補程序版本。

您可以將ElementCollection映射爲OneToMany映射到具有人員和類型的Preference對象。這將是一個更直接的模式。

如果您不需要外部聯接（或者如果需要外部聯接語義，則可能使用子查詢），內部聯接也可能工作。