动态SQL之模糊查询

Posted 2020-07-23 菜包包

模糊查询学习了三种:

DAO层

// 可以使用
List<User> wherelike01(String user_name);

// 忘记
List<User> wherelike02(Map<String, Object> map);

// 推荐使用
List<User> wherelike03(String user_name)

测试类

 

@Test
    public void where语句测试01() {
        SqlSession sqlSession = null;
        try {
            sqlSession = MyBatisUtils.getSqlSession();
            sqlSession.getMapper(UserDao.class).wherelike01("宋%");
        } catch (Exception e) {
            logger.debug(e.getMessage());
            throw new RuntimeException(e.getMessage());
        } finally {
            MyBatisUtils.closeSqlSession(sqlSession);
        }
    }
@Test
    public void where语句测试02$() {
        SqlSession sqlSession = null;
        try {
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("account", "宋");
            sqlSession = MyBatisUtils.getSqlSession();
            sqlSession.getMapper(UserDao.class).wherelike02(map);
        } catch (Exception e) {
            logger.debug(e.getMessage());
            throw new RuntimeException(e.getMessage());
        } finally {
            MyBatisUtils.closeSqlSession(sqlSession);
        }
    }
@Test
public void where语句测试03推荐() {
　　SqlSession sqlSession = null;
　　try {
　　　　sqlSession = MyBatisUtils.getSqlSession();
　　　　sqlSession.getMapper(UserDao.class).wherelike03("宋");
　　　　} catch (Exception e) {
　　　　　　logger.debug(e.getMessage());
　　　　　　throw new RuntimeException(e.getMessage());
　　　　} finally {
　　　　　　MyBatisUtils.closeSqlSession(sqlSession);
　　　　}
}

Mapper中 

<mapper namespace="com.shxt.dao.UserDao">
       <select id="wherelike01" parameterType="string" resultType="com.shxt.model.User">
         SELECT
            *
        FROM
            USER
        WHERE
            user_name LIKE #{user_name}
       </select>
        <select id="wherelike02" parameterType="map" resultType="com.shxt.model.User">
           SELECT
                *
            FROM
                USER
            WHERE
                user_name LIKE ‘${user_name}%‘
       </select>
         <select id="wherelike03" parameterType="string" resultType="com.shxt.model.User">
           SELECT
                *
            FROM
                USER
            WHERE
                user_name LIKE CONCAT(#{user_name}, ‘%‘)
       </select>
</mapper>