阿西莫夫
2018-01-09 22:01
测试代码如下
@Test
public void testWhere3() {
String hql = "from Commodity c";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objects : list) {
System.out.println("id:" + objects[0]);
}
}
实体类代码:
package com.imooc.model;
import java.io.Serializable;
public class Commodity implements Serializable {
private Long id;//主键
private String name;//名称
private Double price;//价格
private String unit;//单位
private String category;//类别
private String description;//简介
private Seller seller;//商家
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
public String getUnit() {
return unit;
}
public void setUnit(String unit) {
this.unit = unit;
}
public String getCategory() {
return category;
}
public void setCategory(String category) {
this.category = category;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Seller getSeller() {
return seller;
}
public void setSeller(Seller seller) {
this.seller = seller;
}
@Override
public String toString() {
return "Commodity [id=" + id + ", name=" + name + ", price=" + price + ", unit=" + unit + ", category="
+ category + ", description=" + description + ", seller=" + seller + "]";
}
public Commodity() {
super();
}
public Commodity(Long id, String name, Double price, String unit, String category, String description,
Seller seller) {
super();
this.id = id;
this.name = name;
this.price = price;
this.unit = unit;
this.category = category;
this.description = description;
this.seller = seller;
}
public Commodity(String name) {
super();
this.name = name;
}
}
这个老师已经讲过了。只有一个数据时使用List<Object> list = query.list();多个数据才可以使用你所写的数组形式,这是它本身的一个机制。记住就行了
你创建的实体类类型跟Object不匹配,没法转换。
第四行改为Query query = session.createSQLQuery(hql).addEntity(Stock.class);
经过几次试验,发现不能查询单个字段,改成查多个字段,成功了
String hql = "select c.name,c.price from Commodity c";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objects : list) {
System.out.println("name:" + objects[0]);
System.out.println("price:" + objects[1]);
}
---------------------------------------执行结果----------------------------
Hibernate:
select
commodity0_.NAME as col_0_0_,
commodity0_.PRICE as col_1_0_
from
COMMODITY commodity0_
name:玩具人偶
price:1500.0
name:鸭脖
price:15.0
name:腊肠
price:200.0
HQL数据查询基础
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