mybatis使用foreach处理List中的Map mybatis-----传入传出多个参数,都是map或list,批量更新

https://nannan408.iteye.com/blog/2170470

https://blog.csdn.net/xingzhishen/article/details/86424395

 

参数的数据结构是一个ArrayList<Map<String, Integer>>,需要以String,Integer为条件批量更新数据库的数据.

将参数封装到叫做JsonData的qv中,JsonData的关键代码是

private ArrayList<Map<String, Integer>> usersPlatforms;

public ArrayList<Map<String, Integer>> getUsersPlatforms() {
return usersPlatforms;
}

public void setUsersPlatforms(ArrayList<Map<String, Integer>> usersPlatforms) {
this.usersPlatforms = usersPlatforms;
}
Mapper中的方法是:

updateXxxx(JsonData jsonData);
Mapper.xml的sql是:

<update id="updateXxxx" parameterType="JsonData">
UPDATE xxx SET `xx` = 10
<where>
<foreach collection="usersPlatforms" item="userPlatform" open="" close="" separator="OR">
<foreach collection="userPlatform.keys" item="key" open=" user_id = " close="" separator="">
#{key}
</foreach>
<foreach collection="userPlatform.values" item="value" open=" AND platform = " close="" separator="">
#{value}
</foreach>
</foreach>
</where>
</update>
 
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1.前言. 
   如题. 
2.代码. 
(1)mapper.xml. 

<select id="getTest" resultType="java.util.HashMap" parameterType="java.util.HashMap" >
          select count(1) as c1,userid as c2 from  test where insertime  <![CDATA[>=]]> #{beginTime,jdbcType=TIMESTAMP} and insertime <![CDATA[<]]> #{endTime,jdbcType=TIMESTAMP} group by  userid
   </select>

(2)interface 

public interface TestMapper{

    List<Map<String,Object>> getTest(Map<String,Object> map);
}

(3) 
测试类: 

@Test
public void test3(){
    SimpleDateFormat sf=new SimpleDateFormat("yyyyMMddHH");
    Date d1 = null;
    try {
        d1 = sf.parse("2014061100");
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    Date d2 = null;
    try {
        d2 = sf.parse("2014121100");
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    //new
    Map map=new HashMap<String, Object>();
    map.put("beginTime", d1);
    map.put("endTime", d2);
    List list=testMapper.getTest(map);
    System.out.println(list.size());
}

2.批量更新. 
   大部分传list就可以了,传map也可以,但map也要解析成list,可以自行研究map,这里介绍通用的list传值方法: 
(1)mapper 

public  int batchUpdate(List<Test> list);

(2)xml 

 <update id="batchUpdate" parameterType="java.util.List">
            <foreach collection="list" item="list" index="index" open="begin" close=";end;" separator=";">
         update Test
         <set>
            A= A + #{list.a}
        </set>
        where B = #{list.b}
        </foreach >
</update>

(3)测试类 

public void testBatchUpdate(){
        List<Test > item=new ArrayList<Test>();
        for(int i=0;i<10;i++){
            Test Test=new Test();
            Test.setA(i+10);
            Test.setB("kkk");
            item.add(Test);
        }
    int count=  TestMapper.batchUpdate(item);
    System.out.println("jieguo:"+ count);
    }