MyBatis中特殊SQL的执行
目录
1.模糊查询
List<User> getUserByLike(@Param("username") String username);<select id="getUserByLike" resultType="com.atguigu.mybatis.pojo.User">
<!--select * from t_user where username like '%${username}%';-->
<!--select * from t_user where username like concat('%',#{username},'%');-->
select * from t_user where username like "%"#{username}"%";
</select>@Test
public void testGetUserByLike() {
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
SqlMapper mapper = sqlSession.getMapper(SqlMapper.class);
List<User> userList = mapper.getUserByLike("an");
userList.forEach(System.out::println);
}
2.批量删除
int deleteMore(@Param("ids")String ids);<!-- 批量删除不能使用#{}，因为#{}会自动添加单引号，语法错误，必须使用${}-->
<delete id="deleteMore">
delete
from t_user
where id in (${ids});
</delete>@Test
public void testDeleteMore() {
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
SqlMapper mapper = sqlSession.getMapper(SqlMapper.class);
int row = mapper.deleteMore("1,2,8");
System.out.println(row);
}3.动态设置表名
List<User> getUserByTableName(@Param("tableName") String tableName);<select id="getUserByTableName" resultType="User">
select *
from ${tableName};
</select>@Test
public void testGetUserByTableName() {
SqlSession sqlSession = SqlSessionUtils.getSqlSession();
SqlMapper mapper = sqlSession.getMapper(SqlMapper.class);
List<User> tableName = mapper.getUserByTableName("t_user");
tableName.forEach(System.out::println);
}4.添加功能获取自增的主键
/**
* 添加用户信息 添加功能获取自增的主键
* @param user
* @return
* useGeneratedKeys：设置使用自增的主键
* keyProperty：因为增删改有统一的返回值是受影响的行数，
* 因此只能将获取的自增的主键放在传输的参数user对象的某个属性中
*/
int insertUser(User user);<insert id="insertUser" useGeneratedKeys="true" keyProperty="id">
insert into t_user
values (null, #{username}, #{password}, #{age}, #{sex}, #{email});
</insert>
pper>原文地址：https://blog.csdn.net/Helen_1997_1997/article/details/143953326
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