• mybatis之parameterType传递多个参数


    当在查询的时候需要传入多个参数的时候该怎么办呢:

    1,封装成一个Model对象,底层HashMap还是一个

    User user=new User();
    
    user.setUserName("zhangsan");
    
    user.setPassword("123456");
    
    queryUserByuserNameAndPass(user);//为返回值类型为User
    <select id="queryUserByuserNameAndPass"  resultType="User" parameterType="com.j1.User"  >
    
           select * from user u where u.user_name=#{userName} and u.pass_word=#{passWord}
    
    </select>

    2,使用HashMap封装

    //使用HashMap定义:
    
    HashMap <String,Object> map=new HashMap<String,Object>();
    
    map.put("userName","zhangsan");
    
    map.put("password","123456");
    
    queryUserByuserNameAndPass(map);//为返回值类型为User

    //sql 如下:

    <select id="queryUserByuserNameAndPass"  resultType="User"  parameterType="Map" >
    
    select * from user u where u.user_name=#{userName} and u.pass_word=#{passWord}
    
    </select>

    3,使用注解,@param

    queryUserByuserNameAndPass(@param(''userName")String userName,@param("password")String password)
    <select id="queryUserByuserNameAndPass"  resultType="User">
    
    select * from user u where u.user_name=#{userName} and u.pass_word=#{passWord}//
    
    </select>
    queryUserByuserNameAndPass(String userName,String PassWord);  //返回值类型为Usre  

    //sql

    <select id="queryUserByuserNameAndPass"  resultType="User">
    
    select * from user u where u.user_name=#{userName} and u.pass_word=#{passWord}//会报错的
    
    </select>
    
     

    改为如下:

    <select id="queryUserByuserNameAndPass"  resultType="User">
    
    select * from user u where u.user_name=#{0} and u.pass_word=#{1}//运行成功但是,可读性不高
    
    </select>
    
     

    //parameterType 参数类型可以是基本数据类型(int,String,long),可以是Model对象,也可以是Map;

    1,基本数据类型:

    //java代码
    
    @Override
    public void deleteUserById(Long id) {
    SqlSession sqlSession = sqlSessionFactory.openSession(true);
    sqlSession.delete("cn.itcast.mybatis.user.deleteUserById", id);
    }

    //sql

    <delete id="deleteUserById" parameterType="java.lang.Long">
          DELETE FROM tb_user WHERE id = #{id}
    </delete>

    2,Model对象

    //java代码:
    
    @Override
    public void saveUser(User user) {
    SqlSession sqlSession = sqlSessionFactory.openSession(true);
    sqlSession.insert("cn.itcast.mybatis.user.saveUser", user);
    }
    
    @Override
    public void updateUser(User user) {
    SqlSession sqlSession = sqlSessionFactory.openSession(true);
    sqlSession.update("cn.itcast.mybatis.user.updateUser", user);
    }

    //sql

    <update id="updateUser" parameterType="cn.itcast.mybatis.pojo.User">
    UPDATE tb_user
    SET
    password = #{password},
    name = #{name},
    age = #{age},
    sex = #{sex},
    birthday = #{birthday},
    updated = NOW()
    WHERE
    id = #{id};
    </update>

    3.map

    //java
    
    HashMap <String,Object> map=new HashMap<String,Object>();
    
    map.put("userName","zhangsan");
    
    map.put("password","123456");
    
    queryUserByuserNameAndPass(map);//为返回值类型为User

    //sql 如下:

    <select id="queryUserByuserNameAndPass"  resultType="User">
    
    select * from user u where u.user_name=#{userName} and u.pass_word=#{passWord}//
    
    </select>
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  • 原文地址:https://www.cnblogs.com/wangchuanfu/p/5877169.html
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