已知商品和种类pojo类的代码如下:public class Product { private int id; private String name;private float price; private Category category;} public class Category{private int cid; private String cname;} 商品表和种类表中的表名及列名和pojo类的类名及属性名完全一致,要求:(1)在mybatis映射文件中,使用<resultMap>元素进行关联映射。 (2)只写mybatis映射文件中的<mapper>、<resultMap>元素及<select>元素内容。
时间: 2024-04-03 20:31:42 浏览: 17
<mapper namespace="com.example.mapper.ProductMapper">
<resultMap id="productMap" type="Product">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="price" column="price"/>
<association property="category" javaType="Category">
<id property="cid" column="cid"/>
<result property="cname" column="cname"/>
</association>
</resultMap>
<select id="selectProductById" resultMap="productMap">
SELECT * FROM product p
LEFT JOIN category c ON p.cid = c.cid
WHERE id = #{id}
</select>
</mapper>
相关问题
2、已知商品和种类 pojo 类的代码如下: public class Product { private int id ; private String name ; private float price ; private Category category ; public class Category { private int cid ; private String cname ; 商品表和种类表中的表名及列名和 pojo 类的类名及属性名完全一致,要求: (1)在 mybatis 映射文件中,使用< resultMap >元素进行关联映射。 (2)只写 mybatis 映射文件中的< mapper >、< resultMap >元素及< select >元素内容。 当前编程语言为: JAVA
<mapper namespace="com.example.ProductMapper">
<resultMap id="productMap" type="com.example.Product">
<id property="id" column="id"/>
<result property="name" column="name"/>
<result property="price" column="price"/>
<association property="category" javaType="com.example.Product.Category">
<id property="cid" column="cid"/>
<result property="cname" column="cname"/>
</association>
</resultMap>
<select id="selectProductById" resultMap="productMap">
SELECT p.*, c.cid, c.cname
FROM product p
INNER JOIN category c ON p.cid = c.cid
WHERE p.id = #{id}
</select>
</mapper>
注意:以上代码仅供参考,具体的表名和列名需要根据实际情况修改。同时,在使用关联映射时,需要保证 pojo 类之间的属性名和类型与映射文件中的一致。
帮我写一个类名为Emp 的pojo类 代码
好的,以下是 Emp 类的代码:
```
public class Emp {
private int id;
private String name;
private int age;
private String gender;
private String department;
public Emp(int id, String name, int age, String gender, String department) {
this.id = id;
this.name = name;
this.age = age;
this.gender = gender;
this.department = department;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getDepartment() {
return department;
}
public void setDepartment(String department) {
this.department = department;
}
}
```