【发布时间】:2013-11-25 12:48:13
【问题描述】:
我找不到更好的问题,所以我希望它能说明我在问什么。
我有 3 个实体(我只会编写对更好阅读真正重要的代码
Foo.java
@Data
@Entity
@Table(name = "foo", schema = "pl")
@SequenceGenerator(name = "sequence_generator", sequenceName = "pl.foo_seq", allocationSize = 1)
@EqualsAndHashCode(callSuper = false, exclude = {"Doos" })
@ToString(callSuper = true, exclude = { "Doos" })
public class Foo extends BaseEntity{
[...]
@OneToMany(mappedBy = "pk.foo")
private Set<FooDooRel> Doos= new HashSet<FooDooRel>();
public void addDoo(FooDooRel fooDooRel) {
if (fooDooRel== null) {
return;
}
if (!Doos.contains(fooDooRel)) {
Doos.add(fooDooRel);
}
}
[...]
}
FooDooRel.java(具有私有构造函数 FooDooRel())
@Getter
@Setter
@Entity
@Table(name = "foo_doo_rel", schema = "pl")
@EqualsAndHashCode
@ToString(callSuper = true, exclude = { "pk" })
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class FooDooRel implements IEntity {
@EmbeddedId
private FooDooRelId pk;
public FooDooRel(Doo doo, Foo foo) {
if (doo == null || foo == null) {
throw new IllegalArgumentException("Foo or Doo equals null");
}
doo.addFoo(this);
foo.addDoo(this);
pk = new FooDooRelId(doo, foo);
}
[...]
}
FooDooRelId.java(具有私有构造函数 FooDooRelId())
@Getter
@Setter
@Embeddable
@EqualsAndHashCode
@ToString(callSuper = true, exclude = { "doo", "foo" })
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class FooDooRelId implements Serializable {
@ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.REFRESH })
@JoinColumn(name = "doo_id")
private Doo doo;
@ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.REFRESH })
@JoinColumn(name = "project_id")
private Foo foo;
public FooDooRelId(Doo doo, Foo foo) {
setDoo(doo);
setFoo(foo);
}
}
Doo.java
@Data
@Entity
@Table(name = "doo", schema = "pl")
@SequenceGenerator(name = "sequence_generator", sequenceName = "pl.doo_seq", allocationSize = 1)
@EqualsAndHashCode(callSuper = false, exclude = {"Foos" })
@ToString(callSuper = true, exclude = { "Foos" })
public class Doo extends BaseEntity{
[...]
@OneToMany(mappedBy = "pk.doo")
private Set<FooDooRel> Foos= new HashSet<FooDooRel>();
@Column(name = "dispid", nullable = false)
private String dispid;
public void addFoos(FooDooRel fooDooRel) {
if (fooDooRel== null) {
return;
}
if (!Foos.contains(fooDooRel)) {
Foos.add(fooDooRel);
}
}
[...]
}
现在我必须为我的过滤器创建别名
Criteria criteria = getSession().createCriteria(Foo.java, "foo")
criteria.createAlias("Doos", "Disp5", JoinType.LEFT_OUTER_JOIN, Restrictions.eq(Disp5.pk.foo.dispid", "5"));
现在第一个错误,当我这样做时,我得到了这个错误
无法解析属性:pk.foo.dispid of:pl.FooDooRel
我也试过了
criteria.createAlias("Foos", "fooRel", JoinType.LEFT_OUTER_JOIN).createAlias("fooRel.pk.doo", "doo5",
JoinType.LEFT_OUTER_JOIN, Restrictions.eq("dispid", "5"));
或
criteria.createAlias("Foos", "fooRel", JoinType.LEFT_OUTER_JOIN).createAlias("fooRel.pk.doo", "doo5",
JoinType.LEFT_OUTER_JOIN, Restrictions.eq("doo5.dispid", "5"));
我知道我必须进行第二次 JOIN 才能将 FooDooRel 与 Doo 一起加入,但我不知道该怎么做。我可以为 FooDooRel 创建别名,但如何在相同的条件下更进一步到 Doo。
第二个,当我这样做时,我必须从同一个集合中做 2 个别名
Criteria criteria = getSession().createCriteria(Foo.java, "foo")
criteria.createAlias("Doos", "Disp5", JoinType.LEFT_OUTER_JOIN, Restrictions.eq(Disp5.pk.foo.dispid", "5"));
criteria.createAlias("Doos", "Disp6", JoinType.LEFT_OUTER_JOIN, Restrictions.eq(Disp5.pk.foo.dispid", "6"));
我收到一个错误,该路径重复
首先,如何通过检查 Doo 中的 dispid 将 FooDooRel 加入到 Foo,其次如何从同一路径加入 2 个别名?
我不能使用子查询(DetachedCriteria)。
我不想写很多,但是在我之前的问题中,有人告诉我我的上帝不好,所以我添加了我认为我应该添加的所有内容。这基本上是由@ManyToOne 从“内部”连接的 3 个实体的示例。还有一个实体有embeddableId。我希望您能理解我的实体,我的问题是关于标准,并通过从第三个实体添加标准来为第一个实体创建别名。
【问题讨论】:
标签: java hibernate hibernate-criteria