MyBatis傳入多個引數時parameterType的寫法

2022-12-23 14:01:06

MyBatis傳入多個引數時parameterType寫法

方法1：物件

1.保證類裡有建構函式

public Student(Integer SID, String sname, String ssex, Integer sage) {
        this.SID = SID;
        Sname = sname;
        Ssex = ssex;
        Sage = sage;
    }

2.介面裡方法傳物件

public  int insertStudent(Student student);

3.Student Mapper.xml裡

 <insert id="insertStudent"  parameterType="com.tulun.maventest.pojo.Student" >
        insert into  student(SID, Sname, Sage, Ssex)  values (#{SID}, #{Sname}  ,#{Sage}, #{Ssex} )
    </insert>

4.MyBatisDemo的insertStudent() 裡

StudentMapper mapper = sqlSession.getMapper(StudentMapper.class);
 Student student=new Student(10,"小明","男",24);
 System.out.println(mapper.insertStudent(student));
 sqlSession.commit();//事務

方法2：Map

原理是將引數放到HashMap裡，傳一個Map物件，通過鍵值對的形式獲取

1.xml檔案

 <update id="updateSnameById"  parameterType="Map" >
        update Student set sname = #{sname} where sid = #{sid}
    </update>

2.介面

public int updateSnameById(Map map);

3.test.java裡

Map<String,String> map=new HashMap<String,String>();
                map.put("sid","4");
                map.put("sname","劉能");
                System.out.println(mapper.updateSnameById(map));  
                sqlSession.commit();//

方法3：@Param()

在介面裡面該方法的引數前面加註解

1.介面

public int updateSnameById(@Param(value="sid")Integer sid,@Param(value="sname") String sname);

2.xml檔案

<update id="updateSnameById"  parameterType="com.tulun.maventest.pojo.Student" >
        update Student set sname = #{sname} where sid = #{sid}
    </update>

3.test.java

System.out.println(mapper.updateSnameById(4, "劉心晶"));
sqlSession.commit();//事務

MyBatis傳入多個引數批次更新

Service呼叫

Map<String, Object> params = new HashMap<>();
List<Long> ids = new ArrayList<>();
Long donwCnt = 20L;
params.put("ids", ids);
params.put("downCnt", donwCnt);
boolean result = userMapper.batchUpdateByIds(params);

Mapper 方法

boolean batchUpdateByIds(Map<String, Object> params) throws Exception;

Xml內容

<update id="batchUpdateByIds"  parameterType="java.util.Map" >
    update user
    <set>
        down_cnt = #{downCnt}
        where id in
        <foreach collection="ids" index="index" item="item" open="(" separator="," close=")" >
            #{item}
        </foreach>
    </set>
</update>