Mybatis学习第二天

mybatis 内置别名_int 代表 java中的基本类型intint 代表 java中的类类型Integer

其中的#{id},#{name}对应Category2类中的id和name，使用#{}可以防止sql注入

Category.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.how2java.pojo">
<insert id="addCategory" parameterType="Category2">
insert into category (name) values (#{name})
</insert>

<delete id="deleteCategory" parameterType="Category2">
delete from category where id= #{id}
</delete>

<select id="getCategory" parameterType="_int" resultType="Category2">
select * from category where id= #{id}
</select>

<update id="updateCategory" parameterType="Category">
update category set name= #{id} where id= #{id}
</update>
<select id="listCategory" resultType="Category2">
select * from category
</select>
</mapper>

测试类，增删改查

package com.how2java.pojo;


import java.io.IOException;
import java.io.InputStream;
import java.util.List;


import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;


public class TestMybatis {
public static void main(String[] args){
String resource = "mybatis-config.xml";
InputStream is = null;;
try {
is = Resources.getResourceAsStream(resource);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(is);
SqlSession session = ssf.openSession();



// Category2 c2 = new Category2();
// c2.setId(123);
// c2.setName("新增加的Category");
// session.insert("addCategory",c2);
// listAll(session);
//
// session.commit();
// session.close();

// for(int i = 0;i < 4;i++){
// Category2 temp = new Category2();
// temp.setName("Name" + i);
// session.insert("addCategory",temp);
// }
//
Category2 c2 = new Category2();
c2.setId(3);
session.delete("deleteCategory", c2);
//
// Category2 c2 = session.selectOne("getCategory", "3");
// System.out.println(c2.getId() + "==" + c2.getName());

// Category2 c2 = new Category2();
// c2.setId(1);
// c2.setName("黄玥瑶");
// session.update("updateCategory",c2);
listAll(session);

session.commit();
session.close();

}

public static void listAll(SqlSession session){
List<Category2> cs = session.selectList("listCategory");
for(Category2 c : cs){
System.out.println(c.getName());
}
}
}