springboot @Select @Insert @Update @Delete@Options

骑猪看日落 2022-05-23 13:51 266阅读 0赞

@RequestMapping("/select")
    	@ResponseBody
    	public void select() {
    		System.out.println(userMapper.findByName("Michael").toString());
    	}
    	@RequestMapping("/select2")
    	@ResponseBody
    	public void select2() {
    		System.out.println(userMapper.findByName2("Michael").toString());
    	}
    	@RequestMapping("/select3")
    	@ResponseBody
    	public void select3() {
    		System.out.println(userMapper.findByName3("Michael").toString());
    	}
    	@RequestMapping("/insert")
    	@ResponseBody
    	public void insert() {
    		System.out.println(userMapper.insert("sasa"));
    	}
    
    	@RequestMapping("/insert2")
    	@ResponseBody
    	public void insert2() {
    		Map<String, Object> map=new HashMap<>();
    		map.put("name","zhangsan");
    		System.out.println(userMapper.insert2(map));
    	}
    
    
    	@RequestMapping("/insert3")
    	@ResponseBody
    	public void insert3() {
    		User user=new User();
    		user.setName("lisi");
    		System.out.println(userMapper.insert3(user));
    	}

@Select("SELECT * FROM USER WHERE NAME = #{name}")
        User findByName(@Param("name") String name);
    
        @Insert("INSERT INTO USER(NAME) VALUES(#{name})")
        int insert(@Param("name") String name);
    
        @Update("update user set name =#{name} where id=#{id}")
        int update(@Param("id") int id,@Param("name") String name);
    
        @Delete("delete from user where name =#{name}")
        int delete(@Param("name") String name);
    
        //注解中动态拼接sql
        @Select("<script>" +
                "SELECT * FROM USER WHERE NAME = #{name}" +
                "</script>")
        User findByName2(@Param("name") String name);
        //拼装返回结果在该配置中故意没有查出id属性，只对User对应中的name做了映射配置，
        // 这样可以通过下面的单元测试来验证查出的id为空，而其他属性不为null
        @Select("<script>" +
                "SELECT name FROM USER WHERE NAME = #{name}" +
                "</script>")
        @Results(
                @Result(property ="name" ,column ="name" )
        )
        User findByName3(@Param("name") String name);
        //Map参数传递
        @Insert("INSERT INTO USER(NAME) VALUES(#{name})")
        int insert2(Map<String, Object> map);
        //对象参数传递
        @Insert("INSERT INTO USER(NAME) VALUES(#{name})")
        int insert3(User user);

如果再插入数据库的时候想要返回主键最大值可用@Options注解，在插入成功后，即可获取主键字段的值。

@Insert("<script>" +
                "INSERT INTO USER(NAME) VALUES(#{name})" +
                "</script>")
        @Options(useGeneratedKeys = true,keyProperty = "id",keyColumn = "id")
        int insert3(User user);

这里的int返回值是操作数据库成功的次数，user.getId()可得到主键int的值。