我有两个名为 Banneers 和 BannerGroup 的课程。
我想创建一个关系船ManyToOne。
因为在我的情况下,许多横幅可以有相同的横幅组。
Mysql 表是...
mysql> desc Banners;
+------------------+--------------+------+-----+---------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+------------------+--------------+------+-----+---------+-----------------------------+
| banner_id | int(11) | NO | PRI | NULL | auto_increment |
| banner_name | varchar(255) | YES | | NULL | |
| banner_group_id | int(11) | YES | MUL | NULL | |
+------------------+--------------+------+-----+---------+-----------------------------+
mysql> desc Banner_Group;
+---------------------+--------------+------+-----+----------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+--------------+------+-----+----------------+-----------------------------+
| group_id | int(11) | NO | PRI | NULL | auto_increment |
| group_name | varchar(255) | NO | MUL | NULL | |
+---------------------+--------------+------+-----+----------------+-----------------------------+
我的模型课是这样的......
Class Banners
{
private Integer bannerId;
private String bannerName;
private Integer bannerGroupId;
private BannerGroup bannerGroupDO;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name = "banner_id")
public Integer getBannerId() {
return bannerId;
}
public void setBannerId(Integer bannerId) {
this.bannerId = bannerId;
}
@Column(name = "banner_name")
public String getBannerName() {
return bannerName;
}
public void setBannerName(String bannerName) {
this.bannerName = bannerName;
}
@Column(name = "banner_group_id")
public Integer getBannerGroupId() {
return bannerGroupId;
}
public void setBannerGroupId(Integer bannerGroupId) {
this.bannerGroupId = bannerGroupId;
}
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "group_id")
public AffiliateBannerGroup getAffiliateBannerGroupDO() {
return affiliateBannerGroupDO;
}
public void setAffiliateBannerGroupDO(
AffiliateBannerGroup affiliateBannerGroupDO) {
this.affiliateBannerGroupDO = affiliateBannerGroupDO;
}
}
Class BannerGroup{
private int group_id;
private int group_name;
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name = "group_id")
public Integer getGroupId() {
return groupId;
}
public void setGroupId(Integer groupId) {
this.groupId = groupId;
}
@Column(name = "group_name")
public String getGroupName() {
return groupName;
}
public void setGroupName(String groupName) {
this.groupName = groupName;
}
}
现在,当我试图这样做时......
Query q = session.createQuery("from com.abc.xyz.model.Banners ");
List<Banners> bannerDisplayList = q.list();
它给了我以下异常...
Caused by: com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: Unknown column 'b0_.group_id' in 'field list'.
当我看到我的一般查询日志时,它给了我这个......
131001 9:42:51 230 Query select b0_.banner_id as banner1_247_, b0_.group_id as group25_247_, b0_.banner_group_id as banner3_247_, b0_.banner_name as banner2_247_ from Banners b0_
230 Query SHOW FULL TABLES FROM `mydb` LIKE 'PROBABLYNOT'
230 Query rollback
230 Query SET autocommit=1
这意味着@joinColumn在这个 ManyToOne 关系中不起作用。
我的代码错了吗?这里有什么问题?