hql内部联接加入的路径！错误 [英] hql inner join Path expected for join! error

问题描述

您好有以下实体：

  @Entity 
公共类FilesInfo {
 @Id 
 @GeneratedValue 
私人整数ID; 
私人字符串名称; 
私人字符串网址; 
 
 @OneToMany（cascade = CascadeType.ALL）
 @JoinColumn（name =fileId）
 private Collection< FilesShare> filesShared = new ArrayList< FilesShare>（）; 
 
公共集合< FilesShare> getFilesShared（）{
 return filesShared; 
} 
 
 public void setFilesShared（Collection< FilesShare> filesShared）{
 this.filesShared = filesShared; 
} 
 // getters& setters 
} 
  

另一个

  @Entity 
 public class FilesShare {
 private Integer id; 
 private int userId; 
 private int owner; 
} 
  

结算表格为：

  mysql> desc filesshare; 
 + -------- + --------- + ------ + ----- + --------- + --- ------------- + 
 |字段|类型|空| Key |默认|额外| 
 + -------- + --------- + ------ + ----- + --------- + --- ------------- + 
 | id | int（11）| NO | PRI | NULL | auto_increment | 
 | userId | int（11）| NO | | NULL | | 
 |所有者| int（11）| NO | | NULL | | 
 | fileId | int（11）|是| MUL | NULL | | 
 + -------- + --------- + ------ + ----- + --------- + --- ------------- + 
 4行设置（0.01秒）
 
 mysql> desc filesinfo; 
 + ------- + -------------- + ------ + ----- + --------- + ---------------- + 
 |字段|类型|空| Key |默认|额外| 
 + ------- + -------------- + ------ + ----- + --------- + ---------------- + 
 | id | int（11）| NO | PRI | NULL | auto_increment | 
 |名称| varchar（255）|是| | NULL | | 
 | url | varchar（255）|是| | NULL | | 
 + ------- + -------------- + ------ + ----- + --------- + ---------------- + 
 3行（0.00秒）
  

我想让hql成为下面的sql：

  select a.id ，a.name，来自FilesInfo的a.url内部连接FilesShare b 
对于a.id = b.fileid其中b.userid = 5和b.owner = 1; 
  

给出以下输出：

 的MySQL>从FilesInfo中选择a.id，a.name，a.url，在内部加入FilesShare b。 
 id = b.fileid其中b.userid = 5和b.owner = 1; 
 + ---- + ------------------- + -------------------- ----------------- + 
 | id |名称| url | 
 + ---- + ------------------- + -------------------- ----------------- + 
 | 1 | dwnld_btn_1.png | C：\shareapp\admin\dwnld_btn_1.png | 
 | 2 | dwnld_btn_1.png | C：\shareapp\admin\dwnld_btn_1.png | 
 | 3 | dwnld_btn_1.png | C：\shareapp\admin\dwnld_btn_1.png | 
 | 4 | dwnld_btn_1_1.png | C：\shareapp\admin\dwnld_btn_1_1.png | 
 + ---- + ------------------- + -------------------- ----------------- + 
  

我尝试了以下hql：

 从文件信息中选择a.id，a.name，a.url一个内部加入FilesShare b 
，其中a.id = b.fileid和b.userid = 5和b.owner = 1 
  

但我收到此错误

加入的路径！ [选择a.id，a.name，a.url从
app.domain.FilesInfo内部连接FilesShare b，其中a.id = b.fileid和
b.userid = 5和b.owner = 1]

现在如何做内连接，是问题

thankyou

解决方案

您的查询需要路径，您可以参考此问题获取详细信息：HQL错误：预计加入的路径。

所以，像这样的东西应该可以解决它：

 从FilesInfo中选择a.id，a.name，a.url一个内部联接a。 filesShared b where b.userid = 5 and b.owner = 1; 
  

---

但是我只需要在您的ManyToOne映射FilesShare：

  private FilesInfo filesInfo; 
 
 @ManyToOne 
 @JoinColumn（name =id）
 public FilesInfo getFilesInfo（）{
 return filesInfo; 
} 
 
 public void setFilesInfo（FilesInfo filesInfo）{
 this.filesInfo = filesInfo; 
} 
  

并执行此查询

来自FilesShare的

 ，其中userId = 5且拥有者= 1 
  

它看起来更好，并返回文件共享列表，每个文件共享都拥有父项（ filesInfo ）字段。

hi have following entities;

@Entity
public class FilesInfo {
    @Id
    @GeneratedValue
    private Integer id;
    private String name;
    private String url;

    @OneToMany(cascade= CascadeType.ALL)
    @JoinColumn(name="fileId")
    private Collection<FilesShare> filesShared = new ArrayList<FilesShare>();

    public Collection<FilesShare> getFilesShared() {
        return filesShared;
    }

    public void setFilesShared(Collection<FilesShare> filesShared) {
        this.filesShared = filesShared;
    }
 //getters & setters   
}

the other one

@Entity
public class FilesShare {
    private Integer id;
    private int userId;
    private int owner;
}

the resultand tables are:

mysql> desc filesshare;
+--------+---------+------+-----+---------+----------------+
| Field  | Type    | Null | Key | Default | Extra          |
+--------+---------+------+-----+---------+----------------+
| id     | int(11) | NO   | PRI | NULL    | auto_increment |
| userId | int(11) | NO   |     | NULL    |                |
| owner  | int(11) | NO   |     | NULL    |                |
| fileId | int(11) | YES  | MUL | NULL    |                |
+--------+---------+------+-----+---------+----------------+
4 rows in set (0.01 sec)

mysql> desc filesinfo;
+-------+--------------+------+-----+---------+----------------+
| Field | Type         | Null | Key | Default | Extra          |
+-------+--------------+------+-----+---------+----------------+
| id    | int(11)      | NO   | PRI | NULL    | auto_increment |
| name  | varchar(255) | YES  |     | NULL    |                |
| url   | varchar(255) | YES  |     | NULL    |                |
+-------+--------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)

i want to make the hql as i made the sql below:

    select a.id, a.name, a.url from FilesInfo a inner join FilesShare b 
on a.id=b.fileid where b.userid=5 and b.owner=1;

that gives the following output:

mysql> select a.id, a.name, a.url from FilesInfo a inner join FilesShare b on a.
id=b.fileid where b.userid=5 and b.owner=1;
+----+-------------------+-------------------------------------+
| id | name              | url                                 |
+----+-------------------+-------------------------------------+
|  1 | dwnld_btn_1.png   | C:\shareapp\admin\dwnld_btn_1.png   |
|  2 | dwnld_btn_1.png   | C:\shareapp\admin\dwnld_btn_1.png   |
|  3 | dwnld_btn_1.png   | C:\shareapp\admin\dwnld_btn_1.png   |
|  4 | dwnld_btn_1_1.png | C:\shareapp\admin\dwnld_btn_1_1.png |
+----+-------------------+-------------------------------------+

i tried the following hql:

select a.id, a.name, a.url from FilesInfo a inner join FilesShare b 
where a.id=b.fileid and b.userid=5 and b.owner=1

but i am getting this error

Path expected for join! [select a.id, a.name, a.url from app.domain.FilesInfo a inner join FilesShare b where a.id=b.fileid and b.userid=5 and b.owner=1]

how to do inner join now, is the question

thankyou

解决方案

Your query requires path, you can refer to this question for details: HQL ERROR: Path expected for join.

So, something like this should resolve it:

select a.id, a.name, a.url from FilesInfo a inner join a.filesShared b where b.userid=5 and b.owner=1;

---

But I would just have a ManyToOne mapping in your FilesShare:

private FilesInfo filesInfo;

@ManyToOne
@JoinColumn(name = "id")
public FilesInfo getFilesInfo() {
    return filesInfo;
}

public void setFilesInfo(FilesInfo filesInfo) {
    this.filesInfo = filesInfo;
}

and do this query

from FilesShare where userId = 5 and owner = 1

It looks nicer and returns the list of file shares, each of them having parent (filesInfo) field populated.

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