某个时间段内mysql数据库中的时间平均值

Question

所以我试图在 20 分钟内获取时间平均值并将其从我的主 sql 表添加到辅助表中，该数字将在一天中多次进入数据库，并且在第一次进入该数字时运行良好但是如果它在当天晚些时候进入，它会将辅助表更新为更高的平均值，例如

58 号在上午 12:08 进入，然后在上午 12:31 停止进入，如果它在下午 13:47 回到表中并在下午 14:13 退出，则平均值将显示 23 分钟小时 5 分钟

我正在使用

insert into test.time (beacon,location,date,time_avg,mac,time)
SELECT beacon,location,date, 
TIMEDIFF(max(`time`),min(`time`)) AS `time_avg`,mac,time
FROM test.test where time > now() - interval 30 minute
group by beacon
ORDER BY `time_avg` DESC

我如何查询它以便它在半小时左右添加一个新行，所以我确实尝试使用一个事件，它每 30 分钟而不是每次更新后才查询一次，但我仍然遇到同样的问题，我也尝试过在 mac 是唯一值的地方插入忽略并替换为。

我附上了一张我的表格的图片，以便了解其中的数据。

字符串中的示例数据方便

insert into test ('location','beacon','mac','date','time') VALUES (YELLOW, 1,AC3422845D, 2018-01-10, 12:08:55);

mysql table data

Answer 1

您有很多事情要查看，并且可能会在您的 insert..select 中修复。如果您的目标是在每个信标、mac、日期的插入表中有 1 条记录，那么在重复键上插入可能就是您想要的。例如

MariaDB [沙盒]> 如果存在则删除表 t; 查询正常，0 行受影响（0.27 秒）

MariaDB [sandbox]>
MariaDB [sandbox]> create table t
    -> (location varchar(20),beacon int, mac varchar(20),`date` date, `time` time);
Query OK, 0 rows affected (0.20 sec)

MariaDB [sandbox]> insert into t (location,beacon,mac,`date`,`time`) VALUES ('YELLOW', 1,'AC3422845D', '2018-01-10', '11:00:44');
Query OK, 1 row affected (0.01 sec)

MariaDB [sandbox]> insert into t (location,beacon,mac,`date`,`time`) VALUES ('YELLOW', 1,'AC3422845D', '2018-01-11', '10:00:55');
Query OK, 1 row affected (0.01 sec)

MariaDB [sandbox]> insert into t (location,beacon,mac,`date`,`time`) VALUES ('YELLOW', 1,'AC3422845D', '2018-01-11', '11:00:55');
Query OK, 1 row affected (0.05 sec)

MariaDB [sandbox]> insert into t (location,beacon,mac,`date`,`time`) VALUES ('YELLOW', 1,'AC3422845D', '2018-01-11', '12:00:55');
Query OK, 1 row affected (0.02 sec)

MariaDB [sandbox]>
MariaDB [sandbox]> drop table if exists t1;
Query OK, 0 rows affected (0.08 sec)

MariaDB [sandbox]> create table t1
    -> (beacon int,location varchar(20), mac varchar(20),`date` date, maxtimetime  time, mintime time, obs int, now30 datetime);
Query OK, 0 rows affected (0.26 sec)

MariaDB [sandbox]> alter table t1
    -> add unique key  t1k1 (beacon,mac,`date`);
Query OK, 0 rows affected (0.18 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [sandbox]>
MariaDB [sandbox]>
MariaDB [sandbox]> #select * from t;
MariaDB [sandbox]> #select @now;
MariaDB [sandbox]>
MariaDB [sandbox]> truncate table t1;
Query OK, 0 rows affected (0.27 sec)

MariaDB [sandbox]> set @now = str_to_date('2018-01-10 11:15:00','%Y-%m-%d %H:%i:%s');
Query OK, 0 rows affected (0.00 sec)

MariaDB [sandbox]> insert into t1 (beacon ,mac ,`date`, maxtimetime, mintime, obs, now30)
    -> select *
    -> from
    -> (select t.beacon,t.mac,t.`date`, max(`time`) maxtime,min(`time`) mintime,count(*) obs,
    -> @now - interval 30 minute now30
    -> from t
    -> where `time`  between time(@now - interval 30 minute) and time(@now) and `date` = date(@now)
    -> group by t.beacon ,t.mac,t.`date`
    -> ) s
    -> on duplicate key
    -> update maxtimetime = s.maxtime, mintime = s.mintime, obs = s.obs, now30 = s.now30;
Query OK, 1 row affected (0.03 sec)
Records: 1  Duplicates: 0  Warnings: 0

MariaDB [sandbox]>
MariaDB [sandbox]> select * from t1;
+--------+----------+------------+------------+-------------+----------+------+---------------------+
| beacon | location | mac        | date       | maxtimetime | mintime  | obs  | now30               |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
|      1 | NULL     | AC3422845D | 2018-01-10 | 11:00:44    | 11:00:44 |    1 | 2018-01-10 10:45:00 |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
1 row in set (0.00 sec)

MariaDB [sandbox]>
MariaDB [sandbox]> set @now = str_to_date('2018-01-11 11:15:00','%Y-%m-%d %H:%i:%s');
Query OK, 0 rows affected (0.00 sec)

MariaDB [sandbox]> insert into t1 (beacon ,mac ,`date`, maxtimetime, mintime, obs, now30)
    -> select *
    -> from
    -> (select t.beacon,t.mac,t.`date`, max(`time`) maxtime,min(`time`) mintime,count(*) obs,
    -> @now - interval 30 minute now30
    -> from t
    -> where `time` between time(@now - interval 30 minute) and time(@now) and `date` = date(@now)
    -> group by t.beacon ,t.mac,t.`date`
    -> ) s
    -> on duplicate key
    -> update maxtimetime = s.maxtime, mintime = s.mintime, obs = s.obs, now30 = s.now30;
Query OK, 1 row affected (0.03 sec)
Records: 1  Duplicates: 0  Warnings: 0

MariaDB [sandbox]>
MariaDB [sandbox]> select * from t1;
+--------+----------+------------+------------+-------------+----------+------+---------------------+
| beacon | location | mac        | date       | maxtimetime | mintime  | obs  | now30               |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
|      1 | NULL     | AC3422845D | 2018-01-10 | 11:00:44    | 11:00:44 |    1 | 2018-01-10 10:45:00 |
|      1 | NULL     | AC3422845D | 2018-01-11 | 11:00:55    | 11:00:55 |    1 | 2018-01-11 10:45:00 |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
2 rows in set (0.00 sec)

MariaDB [sandbox]>
MariaDB [sandbox]> set @now = str_to_date('2018-01-11 12:15:00','%Y-%m-%d %H:%i:%s');
Query OK, 0 rows affected (0.00 sec)

MariaDB [sandbox]> insert into t1 (beacon ,mac ,`date`, maxtimetime, mintime, obs, now30)
    -> select *
    -> from
    -> (select t.beacon,t.mac,t.`date`, max(`time`) maxtime,min(`time`) mintime,count(*) obs,
    -> @now - interval 30 minute now30
    -> from t
    -> where `time`  between time(@now - interval 30 minute) and time(@now) and `date` = date(@now)
    -> group by t.beacon ,t.mac,t.`date`
    -> ) s
    -> on duplicate key
    -> update maxtimetime = s.maxtime, mintime = s.mintime, obs = s.obs, now30 = s.now30;
Query OK, 2 rows affected (0.02 sec)
Records: 1  Duplicates: 1  Warnings: 0

MariaDB [sandbox]>
MariaDB [sandbox]> select * from t1;
+--------+----------+------------+------------+-------------+----------+------+---------------------+
| beacon | location | mac        | date       | maxtimetime | mintime  | obs  | now30               |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
|      1 | NULL     | AC3422845D | 2018-01-10 | 11:00:44    | 11:00:44 |    1 | 2018-01-10 10:45:00 |
|      1 | NULL     | AC3422845D | 2018-01-11 | 12:00:55    | 12:00:55 |    1 | 2018-01-11 11:45:00 |
+--------+----------+------------+------------+-------------+----------+------+---------------------+
2 rows in set (0.00 sec)