【Mybatis】- 一般开发规范

忘是亡心i 2022-10-02 09:51 161阅读 0赞

[2019独角兽企业重金招聘Python工程师标准>>> ][2019_Python_] ![hot3.png][]

## Mybatis 一般开发规范(mapper.xml) ##

1.  namespace命令空间:Mapper接口代理使用
2.  namespce:须与mapper接口名字一致，sql片段完成接口方法映射
3.  mapper接口中的方法、参数列表、返回值须一致

sqlMapConfig.xml:

<?xml version="1.0" encoding="utf-8"?>
    <!DOCTYPE configuration
    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-config.dtd">
    
    <configuration>
        
    
    <properties resource="db.properties"/>
     
    
    <typeAliases>
       <typeAlias type="com.zhiwei.domain.User" alias="user"/>
       
       <package name="com.zhiwei.domain" />
    </typeAliases>
    
    
    <environments default="development">
    <environment id="development">
        
    
    <transactionManager type="JDBC"/>
    
    
    <dataSource type="POOLED">
    <property name="driver" value="${jdbc.driver}"/>
    <property name="url" value="${jdbc.url}"/>
    <property name="username" value="${jdbc.user}"/>
    <property name="password" value="${jdbc.password}"/>
    </dataSource>
    </environment>
    </environments>
    
    
    <mappers>
    
       
       <mapper resource="com/zhiwei/domain/UserMapper.xml"/>
       <package name="com.zhiwei.mapper"/>
    </mappers>
    </configuration>

mapper.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.zhiwei.mapper.UserMapper">
        
    
    <resultMap type="com.zhiwei.mapper.User" id="userResultMap">
        <id column="id" property="id"/>
        <result column="name" property="name"/>
        <result column="passwd" property="passwd"/>
    </resultMap>
    
    
    <sql id="Condition">
            <if test="id=1">
                id=2;
            </if>
    </sql>
    
    <select id="findUser" parameterType="int" resultMap="userResultMap">
        select id,name,passwd from user 
        
        
        <where>
            
            <include refid="Condition"/>
        </where>
    
    </select>
    
    
    <select id="fingUserList" parameterType="com.zhiwei.pojo.UserQueryVo" resultType="com.zhiwei.pojo.UserCustomer">
       
        select name,passwd from user where user.name=#{userCustomer.name} and user.passwd=#{userCustomer.passwd}
    </select>
    
       
    <select id="findUserById" parameterType="int" resultType="com.zhiwei.mapper.User">
    select *from user where id=#{id}
    </select>
    
    <delete id="deleteUserById" parameterType="int">
    delete from user where id=#{id}
    </delete>
    
    
    <update id="updateUser" parameterType="user">
    update  user set name=#{name},passwd=#{passwd} where id=#{id}
    </update>
    
    
    <insert id="addUser" parameterType="User">
    insert into user(id,name,passwd) values(#{id},#{name},#{passwd})
    </insert>
    </mapper>

测试类：

package com.zhiwei.test;
    
    import java.util.List;
    import org.apache.ibatis.session.SqlSession;
    
    import com.zhiwei.mapper.User;
    import com.zhiwei.mapper.UserMapper;
    import com.zhiwei.pojo.UserCustomer;
    import com.zhiwei.pojo.UserQueryVo;
    import com.zhiwei.tool.MybatisTool;
    
    public class MainTest {
    
    	
    	public static void main(String[] args) throws Exception {
    		
    		SqlSession sqlSession=MybatisTool.getSession();
    		//通过Mapper接口，mybatis自动生成代理对象
    		UserMapper userMapper=sqlSession.getMapper(UserMapper.class);
    		
    		UserQueryVo userQueryVo=new UserQueryVo();
    		
    		UserCustomer userCustomer=new UserCustomer();
    		userCustomer.setName("squirrel");
    		userCustomer.setPasswd("xiaoyang");
    		
    		userQueryVo.setUserCustomer(userCustomer);
    		
    		List<UserCustomer> users=userMapper.fingUserList(userQueryVo);
    		System.out.println("pojo:"+users);
    		
    	    User user=userMapper.findUser(1);
    	    System.out.println("resultMap:"+user);
    		
    	}
    }

结果：

DEBUG [main] - Checking to see if class com.zhiwei.mapper.User matches criteria [is assignable to Object]
    DEBUG [main] - Checking to see if class com.zhiwei.mapper.UserMapper matches criteria [is assignable to Object]
    DEBUG [main] - Openning JDBC Connection
    DEBUG [main] - Created connection 1413653265.
    DEBUG [main] - ooo Using Connection [com.mysql.jdbc.JDBC4Connection@5442a311]
    DEBUG [main] - ==>  Preparing: select name,passwd from user where user.name=? and user.passwd=? 
    DEBUG [main] - ==> Parameters: squirrel(String), xiaoyang(String)
    pojo:[]
    DEBUG [main] - ooo Using Connection [com.mysql.jdbc.JDBC4Connection@5442a311]
    DEBUG [main] - ==>  Preparing: select id,name,passwd from user WHERE id=2; 
    DEBUG [main] - ==> Parameters: 
    resultMap:User [id=2, name=lisi, passwd=lisi]

项目结构层次：

![ff8b82530b52c5ad0fae3752a66c145dbc8.jpg][]

转载于:https://my.oschina.net/yangzhiwei256/blog/3017239

[2019_Python_]: https://my.oschina.net/u/2663968/blog/3061697
[hot3.png]: /images/20220113/7c2fffcf11e747bea28efd28cf9e5d36.png
[ff8b82530b52c5ad0fae3752a66c145dbc8.jpg]: /images/20220113/a43220f1f04d467dbaa9545e8e8f5d60.png