[英]Hibernate criteria query throws an exception
I want to get all shops with rating avg less than 4.2. 我希望所有商店的评级平均值低于4.2。 But my criteria throws ClassCastException. 但我的标准抛出ClassCastException。 I have the following criteria query. 我有以下条件查询。
double temp = 4.2;
Criteria criteria = session.createCriteria(Shop.class, "s");
DetachedCriteria avg = DetachedCriteria.forClass(Rating.class, "r")
.setProjection(Projections.avg("r.value"))
.add(Restrictions.eq("r.shopId", "s.id"));
criteria.add(Subqueries.gt(temp, avg));
My entities: 我的实体:
@Entity
@javax.persistence.Table(name = "shop")
public class Shop implements LazyClonable<Shop> {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String name;
@Embedded
private Location location;
@Lob
private String description;
//...getters and setters
}
@Entity
@javax.persistence.Table(name = "rating")
public class Rating implements LazyClonable<Rating> {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
private Float value;
private String comment;
@Transient
@ManyToOne(targetEntity = Shop.class)
@JoinColumn(name = "shop_id", insertable = false, updatable = false)
private Shop shop;
/** foreign key */
@Column(name = "shop_id")
private Integer shopId;
//...getters and setters
}
And it throws the exception. 它抛出异常。 Why? 为什么? What I am doing wrong? 我做错了什么? Exception stack trace: 异常堆栈跟踪:
Mar 29, 2015 4:14:52 PM com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The RuntimeException could not be mapped to a response, re-throwing to the HTTP container
java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Integer
at org.hibernate.type.descriptor.java.IntegerTypeDescriptor.unwrap(IntegerTypeDescriptor.java:36)
at org.hibernate.type.descriptor.sql.IntegerTypeDescriptor$1.doBind(IntegerTypeDescriptor.java:64)
at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:90)
at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:286)
at org.hibernate.type.AbstractStandardBasicType.nullSafeSet(AbstractStandardBasicType.java:281)
at org.hibernate.loader.Loader.bindPositionalParameters(Loader.java:1995)
at org.hibernate.loader.Loader.bindParameterValues(Loader.java:1966)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1901)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1862)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1839)
at org.hibernate.loader.Loader.doQuery(Loader.java:910)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:355)
at org.hibernate.loader.Loader.doList(Loader.java:2554)
at org.hibernate.loader.Loader.doList(Loader.java:2540)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2370)
at org.hibernate.loader.Loader.list(Loader.java:2365)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:126)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1682)
... ...
I have changed query to native SQL but still getting the same exception: 我已将查询更改为本机SQL但仍获得相同的异常:
criteria.add(Restrictions.sqlRestriction(
"(SELECT avg(r.value) FROM rating r WHERE s.id = r.shop_id) < ?", temp, DoubleType.INSTANCE));
With: 附:
Restrictions.eq("r.shopId", "s.id")
you check if the shopId
is equal to string value "s.id"
. 检查shopId
是否等于字符串值"s.id"
。 But shopId
is an integer column and "s.id"
is a string value. 但shopId
是一个整数列, "s.id"
是一个字符串值。 So, it's normal you get an exception. 所以,你得到一个例外是正常的。 Also it isn't want you want. 也不是你想要的。 You can't check equality between columns this way. 您不能以这种方式检查列之间的相等性。 Instead, use: 相反,使用:
Restrictions.eqProperty("r.shopId", "s.id")
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.