mysql - 从 call_log 中获取并发电话的最大数量-6ren

mysql - 从 call_log 中获取并发电话的最大数量

转载作者：行者123 更新时间：2023-11-29 01:43:35

我需要帮助在 MySQL 5.0.77 中设计一个查询，该查询根据下面显示的数据(办公室一天的通话量)返回并发电话的峰值数量。我只想知道一天中任何给定时间同时通话的最多人数是多少。

首先，这是 MySQL 表:

CREATE TABLE `call_log` (
`call_id` int(11) NOT NULL auto_increment,
`call_datetime` datetime default NULL,
`call_length` time default NULL,
PRIMARY KEY  (`call_id`)
)

我用这个命令将数据加载到表中:

LOAD DATA LOCAL INFILE 'call_log_import.csv' INTO TABLE call_log FIELDS TERMINATED BY ',' LINE TERMINATED BY '\n' (call_datetime, call_length);

这里是 CSV 格式的实际行数据:

2012-11-07 5:28:00,0:00:20
2012-11-07 7:04:00,0:00:20
2012-11-07 7:04:00,0:00:30
2012-11-07 7:04:00,0:00:30
2012-11-07 7:25:00,0:00:34
2012-11-07 7:25:00,0:00:37
2012-11-07 7:25:00,0:00:38
2012-11-07 7:30:00,0:00:16
2012-11-07 7:49:00,0:01:29
2012-11-07 7:55:00,0:00:43
2012-11-07 7:55:00,0:00:46
2012-11-07 7:55:00,0:00:46
2012-11-07 8:00:00,0:25:01
2012-11-07 8:00:00,0:00:35
2012-11-07 8:01:00,0:00:35
2012-11-07 8:01:00,0:00:35
2012-11-07 8:02:00,0:00:36
2012-11-07 8:02:00,0:03:03
2012-11-07 8:07:00,0:00:07
2012-11-07 8:08:00,0:00:08
2012-11-07 8:12:00,0:00:34
2012-11-07 8:12:00,0:00:44
2012-11-07 8:18:00,0:01:05
2012-11-07 8:28:00,0:01:05
2012-11-07 8:29:00,0:00:18
2012-11-07 8:31:00,0:00:05
2012-11-07 8:31:00,0:00:00
2012-11-07 8:31:00,0:00:11
2012-11-07 8:32:00,0:00:01
2012-11-07 8:32:00,0:27:26
2012-11-07 8:32:00,0:00:00
2012-11-07 8:32:00,0:00:00
2012-11-07 8:32:00,0:00:00
2012-11-07 8:32:00,0:00:38
2012-11-07 8:33:00,0:00:35
2012-11-07 8:33:00,0:00:04
2012-11-07 8:34:00,0:01:10
2012-11-07 8:35:00,0:09:44
2012-11-07 8:35:00,0:22:21
2012-11-07 8:35:00,0:00:17
2012-11-07 8:35:00,0:21:42
2012-11-07 8:35:00,0:21:46
2012-11-07 8:35:00,0:21:46
2012-11-07 8:37:00,0:00:29
2012-11-07 8:38:00,0:00:29
2012-11-07 8:39:00,0:06:50
2012-11-07 8:39:00,0:08:23
2012-11-07 8:53:00,0:05:01
2012-11-07 8:53:00,0:05:05
2012-11-07 8:53:00,0:05:05
2012-11-07 8:57:00,0:01:04
2012-11-07 9:00:00,0:29:40
2012-11-07 9:01:00,0:00:20
2012-11-07 9:01:00,0:01:27
2012-11-07 9:02:00,0:27:00
2012-11-07 9:03:00,0:26:18
2012-11-07 9:03:00,0:00:18
2012-11-07 9:09:00,0:01:16
2012-11-07 9:12:00,0:02:53
2012-11-07 9:12:00,0:01:09
2012-11-07 9:12:00,0:27:27
2012-11-07 9:14:00,0:07:13
2012-11-07 9:14:00,0:07:18
2012-11-07 9:14:00,0:07:18
2012-11-07 9:18:00,0:11:39
2012-11-07 9:18:00,0:11:55
2012-11-07 9:18:00,0:00:16
2012-11-07 9:17:00,0:12:15
2012-11-07 9:18:00,0:00:48
2012-11-07 9:18:00,0:00:52
2012-11-07 9:18:00,0:00:52
2012-11-07 9:19:00,0:01:12
2012-11-07 9:21:00,0:00:03
2012-11-07 9:22:00,0:02:41
2012-11-07 9:22:00,0:02:36
2012-11-07 9:22:00,0:02:49
2012-11-07 9:24:00,0:01:34
2012-11-07 9:25:00,0:06:10
2012-11-07 9:25:00,0:06:14
2012-11-07 9:25:00,0:06:14
2012-11-07 9:31:00,0:00:43
2012-11-07 9:33:00,0:00:03
2012-11-07 9:33:00,0:00:03
2012-11-07 9:33:00,0:00:03
2012-11-07 9:33:00,0:00:03
2012-11-07 9:33:00,0:00:03
2012-11-07 9:33:00,0:05:57
2012-11-07 9:32:00,0:00:30
2012-11-07 9:32:00,0:00:30
2012-11-07 9:32:00,0:06:28
2012-11-07 9:32:00,0:06:53
2012-11-07 9:32:00,0:00:35
2012-11-07 9:32:00,0:00:20
2012-11-07 9:32:00,0:01:04
2012-11-07 9:32:00,0:01:04
2012-11-07 9:32:00,0:00:41
2012-11-07 9:36:00,0:00:27
2012-11-07 9:37:00,0:23:53
2012-11-07 9:38:00,0:01:51
2012-11-07 9:40:00,0:06:40
2012-11-07 9:40:00,0:06:44
2012-11-07 9:40:00,0:06:44
2012-11-07 9:44:00,0:01:19
2012-11-07 9:46:00,0:00:55
2012-11-07 9:46:00,0:02:01
2012-11-07 9:47:00,0:20:00
2012-11-07 9:47:00,0:02:22
2012-11-07 9:47:00,0:07:12
2012-11-07 9:47:00,0:02:22
2012-11-07 9:47:00,0:00:13
2012-11-07 9:48:00,0:00:41
2012-11-07 9:48:00,0:01:25
2012-11-07 9:50:00,0:01:24
2012-11-07 9:52:00,0:00:06
2012-11-07 9:54:00,0:00:06
2012-11-07 9:57:00,0:00:28
2012-11-07 9:57:00,0:00:20
2012-11-07 9:57:00,0:00:48
2012-11-07 9:58:00,0:00:06
2012-11-07 9:58:00,0:00:06
2012-11-07 9:58:00,0:00:06
2012-11-07 9:58:00,0:00:06
2012-11-07 9:58:00,0:00:06
2012-11-07 9:58:00,0:06:49
2012-11-07 9:58:00,0:07:19
2012-11-07 9:58:00,0:00:30
2012-11-07 9:58:00,0:00:30
2012-11-07 9:58:00,0:07:38
2012-11-07 9:58:00,0:01:36
2012-11-07 9:59:00,0:00:59
2012-11-07 9:59:00,0:01:00
2012-11-07 10:00:00,0:17:43
2012-11-07 10:00:00,0:00:21
2012-11-07 10:00:00,1:02:29
2012-11-07 10:01:00,0:00:03
2012-11-07 10:01:00,0:00:03
2012-11-07 10:01:00,0:00:52
2012-11-07 10:01:00,0:20:23
2012-11-07 10:01:00,0:01:09
2012-11-07 10:01:00,0:00:20
2012-11-07 10:01:00,0:01:15
2012-11-07 10:02:00,0:00:01
2012-11-07 10:02:00,0:00:36
2012-11-07 10:02:00,0:00:48
2012-11-07 10:02:00,0:21:49
2012-11-07 10:03:00,0:40:24
2012-11-07 10:04:00,0:00:02
2012-11-07 10:04:00,0:00:02
2012-11-07 10:04:00,0:00:02
2012-11-07 10:04:00,0:05:59
2012-11-07 10:04:00,0:00:02
2012-11-07 10:04:00,0:00:02
2012-11-07 10:04:00,0:05:59
2012-11-07 10:03:00,0:06:20
2012-11-07 10:03:00,0:00:22
2012-11-07 10:06:00,0:20:35
2012-11-07 10:07:00,0:02:44
2012-11-07 10:08:00,0:00:01
2012-11-07 10:09:00,0:00:29
2012-11-07 10:09:00,0:01:17
2012-11-07 10:10:00,0:00:02
2012-11-07 10:11:00,0:00:02
2012-11-07 10:12:00,0:01:43
2012-11-07 10:12:00,0:24:01
2012-11-07 10:12:00,0:24:04
2012-11-07 10:12:00,0:24:04
2012-11-07 10:12:00,0:01:23
2012-11-07 10:13:00,0:03:51
2012-11-07 10:13:00,0:03:40
2012-11-07 10:14:00,0:09:52
2012-11-07 10:16:00,0:13:33
2012-11-07 10:16:00,0:13:37
2012-11-07 10:16:00,0:13:37
2012-11-07 10:21:00,0:00:20
2012-11-07 10:21:00,0:01:18
2012-11-07 10:21:00,0:01:18
2012-11-07 10:22:00,0:00:21
2012-11-07 10:22:00,0:00:32
2012-11-07 10:22:00,0:00:32
2012-11-07 10:22:00,0:04:31
2012-11-07 10:22:00,0:00:57
2012-11-07 10:23:00,0:10:23
2012-11-07 10:24:00,0:01:20
2012-11-07 10:24:00,0:01:24
2012-11-07 10:24:00,0:01:24
2012-11-07 10:25:00,0:27:34
2012-11-07 10:28:00,0:00:49
2012-11-07 10:30:00,0:01:46
2012-11-07 10:30:00,0:01:51
2012-11-07 10:30:00,0:01:51
2012-11-07 10:30:00,0:01:01
2012-11-07 10:31:00,0:00:43
2012-11-07 10:31:00,0:15:08
2012-11-07 10:33:00,0:02:37
2012-11-07 10:35:00,0:00:21
2012-11-07 10:35:00,0:01:24
2012-11-07 10:35:00,0:01:24
2012-11-07 10:37:00,0:02:07
2012-11-07 10:37:00,0:00:08
2012-11-07 10:38:00,0:00:10
2012-11-07 10:39:00,0:01:37
2012-11-07 10:39:00,0:00:21
2012-11-07 10:39:00,0:01:53
2012-11-07 10:39:00,0:00:03
2012-11-07 10:40:00,0:00:34
2012-11-07 10:41:00,0:00:00
2012-11-07 10:41:00,0:00:00
2012-11-07 10:41:00,0:00:00
2012-11-07 10:41:00,0:02:20
2012-11-07 10:45:00,0:07:57
2012-11-07 10:51:00,0:00:20
2012-11-07 10:51:00,0:00:56
2012-11-07 10:50:00,0:01:12
2012-11-07 10:50:00,0:00:04
2012-11-07 10:50:00,0:00:04
2012-11-07 10:50:00,0:00:04
2012-11-07 10:50:00,0:00:04
2012-11-07 10:50:00,0:00:04
2012-11-07 10:50:00,0:01:44
2012-11-07 10:50:00,0:00:31
2012-11-07 10:50:00,0:00:31
2012-11-07 10:49:00,0:03:05
2012-11-07 10:54:00,0:00:20
2012-11-07 10:54:00,0:01:02
2012-11-07 10:54:00,0:01:02
2012-11-07 10:55:00,0:02:08
2012-11-07 10:56:00,0:00:33
2012-11-07 10:56:00,0:00:05
2012-11-07 10:59:00,0:24:33
2012-11-07 10:59:00,0:24:37
2012-11-07 10:59:00,0:24:37
2012-11-07 11:00:00,0:29:41
2012-11-07 11:00:00,0:07:38
2012-11-07 11:00:00,0:00:51
2012-11-07 11:01:00,0:00:33
2012-11-07 11:02:00,0:28:12
2012-11-07 11:02:00,0:35:02
2012-11-07 11:02:00,0:35:05
2012-11-07 11:02:00,0:35:05
2012-11-07 11:02:00,0:21:29
2012-11-07 11:03:00,0:02:24
2012-11-07 11:03:00,0:02:28
2012-11-07 11:03:00,0:02:28
2012-11-07 11:03:00,0:00:03
2012-11-07 11:04:00,0:34:28
2012-11-07 11:04:00,0:08:20
2012-11-07 11:04:00,0:01:01
2012-11-07 11:06:00,0:16:09
2012-11-07 11:08:00,0:00:50
2012-11-07 11:11:00,0:02:08
2012-11-07 11:14:00,0:01:22
2012-11-07 11:14:00,0:01:26
2012-11-07 11:14:00,0:01:26
2012-11-07 11:14:00,0:00:20
2012-11-07 11:14:00,0:00:57
2012-11-07 11:14:00,0:00:57
2012-11-07 11:15:00,0:09:48
2012-11-07 11:15:00,0:11:10
2012-11-07 11:16:00,0:00:55
2012-11-07 11:18:00,0:00:48
2012-11-07 11:22:00,0:00:51
2012-11-07 11:22:00,0:00:51
2012-11-07 11:22:00,0:00:51
2012-11-07 11:22:00,0:01:16
2012-11-07 11:28:00,0:03:36
2012-11-07 11:29:00,0:13:18
2012-11-07 11:30:00,0:03:47
2012-11-07 11:30:00,0:20:44
2012-11-07 11:30:00,0:01:29
2012-11-07 11:32:00,0:00:39
2012-11-07 11:32:00,0:07:04
2012-11-07 11:35:00,0:02:04
2012-11-07 11:35:00,0:00:20
2012-11-07 11:35:00,0:00:32
2012-11-07 11:35:00,0:00:32
2012-11-07 11:37:00,0:18:14
2012-11-07 11:37:00,0:18:14
2012-11-07 11:37:00,0:00:17
2012-11-07 11:37:00,0:00:18
2012-11-07 11:37:00,0:00:18
2012-11-07 11:36:00,0:18:57
2012-11-07 11:37:00,0:24:10
2012-11-07 11:38:00,0:00:19
2012-11-07 11:38:00,0:00:02
2012-11-07 11:38:00,0:00:02
2012-11-07 11:38:00,0:01:29
2012-11-07 11:41:00,0:00:02
2012-11-07 11:41:00,0:00:02
2012-11-07 11:41:00,0:00:02
2012-11-07 11:41:00,0:04:48
2012-11-07 11:41:00,0:00:02
2012-11-07 11:41:00,0:00:02
2012-11-07 11:41:00,0:04:48
2012-11-07 11:40:00,0:05:09
2012-11-07 11:41:00,0:01:41
2012-11-07 11:42:00,0:15:24
2012-11-07 11:42:00,0:15:30
2012-11-07 11:42:00,0:15:30
2012-11-07 11:59:00,0:00:20
2012-11-07 11:59:00,0:00:31
2012-11-07 11:59:00,0:00:31
2012-11-07 12:00:00,0:08:56
2012-11-07 12:01:00,0:22:31
2012-11-07 12:02:00,0:00:26
2012-11-07 12:02:00,0:33:20
2012-11-07 12:03:00,0:33:45
2012-11-07 12:06:00,0:00:56
2012-11-07 12:18:00,0:00:55
2012-11-07 12:18:00,0:00:55
2012-11-07 12:18:00,0:01:04
2012-11-07 12:24:00,0:00:02
2012-11-07 12:24:00,0:00:02
2012-11-07 12:24:00,0:00:25
2012-11-07 12:25:00,0:00:21
2012-11-07 12:25:00,0:01:08
2012-11-07 12:25:00,0:01:08
2012-11-07 12:26:00,0:00:20
2012-11-07 12:26:00,0:00:54
2012-11-07 12:26:00,0:00:54
2012-11-07 12:29:00,0:00:11
2012-11-07 12:31:00,0:02:10
2012-11-07 12:31:00,0:12:35
2012-11-07 12:31:00,0:06:26
2012-11-07 12:46:00,0:00:34
2012-11-07 12:47:00,0:01:01
2012-11-07 12:47:00,0:01:24
2012-11-07 12:48:00,0:00:15
2012-11-07 12:48:00,0:00:20
2012-11-07 12:48:00,0:00:20
2012-11-07 12:48:00,0:00:18
2012-11-07 12:50:00,0:00:20
2012-11-07 12:50:00,0:00:32
2012-11-07 12:50:00,0:00:32
2012-11-07 12:55:00,0:01:30
2012-11-07 12:55:00,0:01:31
2012-11-07 12:55:00,0:00:17
2012-11-07 12:55:00,0:00:17
2012-11-07 12:55:00,0:00:18
2012-11-07 12:54:00,0:02:13
2012-11-07 12:59:00,0:36:03
2012-11-07 13:00:00,0:09:42
2012-11-07 13:00:00,0:13:35
2012-11-07 13:01:00,0:18:08
2012-11-07 13:01:00,0:28:37
2012-11-07 13:02:00,0:01:26
2012-11-07 13:02:00,0:00:01
2012-11-07 13:02:00,0:09:42
2012-11-07 13:03:00,0:04:53
2012-11-07 13:04:00,0:00:35
2012-11-07 13:12:00,0:14:28
2012-11-07 13:12:00,0:14:28
2012-11-07 13:12:00,0:14:42
2012-11-07 13:13:00,0:00:45
2012-11-07 13:14:00,0:01:27
2012-11-07 13:15:00,0:13:04
2012-11-07 13:14:00,0:13:08
2012-11-07 13:14:00,0:13:08
2012-11-07 13:14:00,0:15:32
2012-11-07 13:15:00,0:00:20
2012-11-07 13:15:00,0:00:30
2012-11-07 13:15:00,0:00:30
2012-11-07 13:16:00,0:00:42
2012-11-07 13:16:00,0:01:04
2012-11-07 13:17:00,0:02:01
2012-11-07 13:22:00,0:00:12
2012-11-07 13:24:00,0:00:02
2012-11-07 13:24:00,0:00:05
2012-11-07 13:24:00,0:00:05
2012-11-07 13:26:00,0:03:07
2012-11-07 13:27:00,0:00:41
2012-11-07 13:29:00,0:02:00
2012-11-07 13:30:00,0:00:17
2012-11-07 13:32:00,0:09:24
2012-11-07 13:32:00,0:25:47
2012-11-07 13:32:00,0:25:50
2012-11-07 13:32:00,0:25:50
2012-11-07 13:33:00,0:03:53
2012-11-07 13:38:00,0:00:01
2012-11-07 13:38:00,0:00:01
2012-11-07 13:39:00,0:27:03
2012-11-07 13:39:00,0:00:20
2012-11-07 13:39:00,0:01:02
2012-11-07 13:39:00,0:01:02
2012-11-07 13:40:00,0:00:00
2012-11-07 13:42:00,0:06:23
2012-11-07 13:42:00,0:00:15
2012-11-07 13:42:00,0:00:15
2012-11-07 13:42:00,0:06:55
2012-11-07 13:41:00,0:07:15
2012-11-07 13:45:00,0:00:33
2012-11-07 13:45:00,0:00:35
2012-11-07 13:46:00,0:01:12
2012-11-07 13:51:00,0:01:55
2012-11-07 13:53:00,0:02:02
2012-11-07 13:55:00,0:00:08
2012-11-07 13:55:00,0:03:42
2012-11-07 13:56:00,0:01:32
2012-11-07 14:01:00,0:00:54
2012-11-07 14:01:00,0:09:24
2012-11-07 14:01:00,0:09:27
2012-11-07 14:01:00,0:09:27
2012-11-07 14:02:00,0:35:17
2012-11-07 14:02:00,0:00:30
2012-11-07 14:02:00,0:35:48
2012-11-07 14:02:00,0:35:48
2012-11-07 14:02:00,0:01:00
2012-11-07 14:04:00,0:34:37
2012-11-07 14:04:00,0:34:37
2012-11-07 14:04:00,0:34:37
2012-11-07 14:05:00,0:04:38
2012-11-07 14:05:00,0:04:38
2012-11-07 14:05:00,0:04:43
2012-11-07 14:06:00,0:00:31
2012-11-07 14:08:00,0:13:06
2012-11-07 14:08:00,0:13:06
2012-11-07 14:06:00,0:01:15
2012-11-07 14:06:00,0:00:03
2012-11-07 14:06:00,0:00:03
2012-11-07 14:06:00,0:01:16
2012-11-07 14:06:00,0:00:03
2012-11-07 14:06:00,0:00:03
2012-11-07 14:06:00,0:00:03
2012-11-07 14:06:00,0:14:39
2012-11-07 14:06:00,0:00:34
2012-11-07 14:06:00,0:00:17
2012-11-07 14:06:00,0:00:21
2012-11-07 14:06:00,0:00:21
2012-11-07 14:07:00,0:11:06
2012-11-07 14:15:00,0:01:37
2012-11-07 14:15:00,0:01:53
2012-11-07 14:15:00,0:00:16
2012-11-07 14:14:00,0:02:19
2012-11-07 14:16:00,0:01:10
2012-11-07 14:19:00,0:04:45
2012-11-07 14:19:00,0:11:31
2012-11-07 14:21:00,0:00:04
2012-11-07 14:21:00,0:00:04
2012-11-07 14:21:00,0:00:00
2012-11-07 14:21:00,0:01:13
2012-11-07 14:21:00,0:00:04
2012-11-07 14:21:00,0:00:04
2012-11-07 14:21:00,0:01:13
2012-11-07 14:21:00,0:01:30
2012-11-07 14:21:00,0:01:43
2012-11-07 14:22:00,0:00:34
2012-11-07 14:23:00,0:03:41
2012-11-07 14:26:00,0:00:20
2012-11-07 14:26:00,0:00:45
2012-11-07 14:26:00,0:00:45
2012-11-07 14:26:00,0:15:39
2012-11-07 14:28:00,0:00:20
2012-11-07 14:28:00,0:02:04
2012-11-07 14:28:00,0:02:04
2012-11-07 14:30:00,0:08:36
2012-11-07 14:31:00,0:10:26
2012-11-07 14:43:00,0:01:16
2012-11-07 14:43:00,0:00:21
2012-11-07 14:43:00,0:01:41
2012-11-07 14:57:00,0:00:21
2012-11-07 14:58:00,0:03:41
2012-11-07 14:58:00,0:00:04
2012-11-07 14:58:00,0:00:04
2012-11-07 14:58:00,0:00:04
2012-11-07 14:58:00,0:00:04
2012-11-07 14:58:00,0:03:42
2012-11-07 14:58:00,0:00:04
2012-11-07 14:57:00,0:04:02
2012-11-07 14:58:00,0:00:20
2012-11-07 14:58:00,0:01:50
2012-11-07 14:58:00,0:01:50
2012-11-07 14:59:00,0:01:42
2012-11-07 14:59:00,0:01:46
2012-11-07 14:59:00,0:01:46
2012-11-07 14:59:00,0:19:45
2012-11-07 15:01:00,0:00:55
2012-11-07 15:02:00,0:00:10
2012-11-07 15:03:00,0:01:13
2012-11-07 15:04:00,0:42:23
2012-11-07 15:05:00,0:02:24
2012-11-07 15:05:00,0:00:36
2012-11-07 15:06:00,0:00:08
2012-11-07 15:06:00,0:00:41
2012-11-07 15:06:00,0:10:57
2012-11-07 15:06:00,0:11:00
2012-11-07 15:06:00,0:11:01
2012-11-07 15:13:00,0:01:42
2012-11-07 15:13:00,0:01:42
2012-11-07 15:13:00,0:00:22
2012-11-07 15:13:00,0:00:23
2012-11-07 15:13:00,0:00:23
2012-11-07 15:12:00,0:02:29
2012-11-07 15:15:00,0:00:19
2012-11-07 15:15:00,0:00:23
2012-11-07 15:15:00,0:00:23
2012-11-07 15:19:00,0:06:07
2012-11-07 15:22:00,0:00:20
2012-11-07 15:21:00,0:01:00
2012-11-07 15:21:00,0:01:00
2012-11-07 15:27:00,0:00:00
2012-11-07 15:27:00,0:00:00
2012-11-07 15:27:00,0:00:01
2012-11-07 15:27:00,0:00:01
2012-11-07 15:27:00,0:00:01
2012-11-07 15:28:00,0:00:01
2012-11-07 15:28:00,0:00:01
2012-11-07 15:28:00,0:01:13
2012-11-07 15:30:00,0:00:20
2012-11-07 15:30:00,0:00:33
2012-11-07 15:30:00,0:00:33
2012-11-07 15:30:00,0:13:31
2012-11-07 15:31:00,0:05:40
2012-11-07 15:31:00,0:05:43
2012-11-07 15:31:00,0:05:43
2012-11-07 15:35:00,0:18:18
2012-11-07 15:35:00,0:18:18
2012-11-07 15:35:00,0:18:18
2012-11-07 15:40:00,0:08:56
2012-11-07 15:40:00,0:08:59
2012-11-07 15:40:00,0:08:59
2012-11-07 15:46:00,0:18:07
2012-11-07 15:49:00,0:01:39
2012-11-07 15:49:00,0:01:40
2012-11-07 15:49:00,0:01:40
2012-11-07 15:48:00,0:01:59
2012-11-07 15:48:00,0:00:02
2012-11-07 15:50:00,0:00:03
2012-11-07 15:50:00,0:00:24
2012-11-07 15:50:00,0:01:17
2012-11-07 15:52:00,0:00:01
2012-11-07 15:52:00,0:01:24
2012-11-07 15:52:00,0:01:24
2012-11-07 15:52:00,0:01:43
2012-11-07 16:01:00,0:00:03
2012-11-07 16:01:00,0:00:02
2012-11-07 16:01:00,0:00:02
2012-11-07 16:02:00,0:00:34
2012-11-07 16:03:00,0:00:42
2012-11-07 16:05:00,0:00:20
2012-11-07 16:05:00,0:00:27
2012-11-07 16:05:00,0:00:27
2012-11-07 16:05:00,0:00:37
2012-11-07 16:14:00,0:00:55
2012-11-07 16:14:00,0:00:56
2012-11-07 16:14:00,0:00:17
2012-11-07 16:14:00,0:00:17
2012-11-07 16:14:00,0:00:17
2012-11-07 16:13:00,0:01:37
2012-11-07 16:16:00,0:01:01
2012-11-07 16:16:00,0:01:05
2012-11-07 16:16:00,0:01:05
2012-11-07 16:18:00,0:00:20
2012-11-07 16:18:00,0:00:30
2012-11-07 16:18:00,0:00:18
2012-11-07 16:18:00,0:00:18
2012-11-07 16:18:00,0:00:19
2012-11-07 16:17:00,0:00:52
2012-11-07 16:20:00,0:00:20
2012-11-07 16:20:00,0:01:41
2012-11-07 16:20:00,0:01:41
2012-11-07 16:41:00,0:25:43
2012-11-07 16:41:00,0:25:44
2012-11-07 16:41:00,0:00:16
2012-11-07 16:41:00,0:00:16
2012-11-07 16:41:00,0:00:17
2012-11-07 16:41:00,0:26:16
2012-11-07 16:50:00,0:00:36
2012-11-07 16:50:00,0:23:05
2012-11-07 16:54:00,0:01:07
2012-11-07 16:55:00,0:00:02
2012-11-07 16:55:00,0:00:02
2012-11-07 16:55:00,0:00:18
2012-11-07 16:59:00,0:01:08
2012-11-07 16:58:00,0:00:05
2012-11-07 16:58:00,0:00:51
2012-11-07 16:58:00,0:00:05
2012-11-07 16:58:00,0:00:05
2012-11-07 16:58:00,0:00:05
2012-11-07 16:58:00,0:00:05
2012-11-07 16:57:00,0:00:30
2012-11-07 16:57:00,0:00:30
2012-11-07 16:57:00,0:01:22
2012-11-07 16:57:00,0:02:55
2012-11-07 17:07:00,0:00:06
2012-11-07 17:07:00,0:02:47
2012-11-07 17:12:00,0:00:09
2012-11-07 17:12:00,0:00:10
2012-11-07 17:12:00,0:00:10
2012-11-07 17:12:00,0:00:28
2012-11-07 17:13:00,0:00:43
2012-11-07 17:14:00,0:02:13
2012-11-07 17:22:00,0:05:11
2012-11-07 17:23:00,0:00:27
2012-11-07 17:28:00,0:00:07
2012-11-07 17:38:00,0:01:25
2012-11-07 17:46:00,0:01:19
2012-11-07 20:34:00,0:00:20
2012-11-07 20:34:00,0:00:36
2012-11-07 20:34:00,0:00:37
2012-11-07 22:49:00,0:00:20
2012-11-07 22:49:00,0:00:29
2012-11-07 22:49:00,0:00:30

最佳答案

对于日志中的每个调用，计算在该 call_datetime 处于事件状态的调用，然后找到最大值:

SELECT MAX(calls) FROM
(SELECT cl1.call_datetime, COUNT(*) AS calls
 FROM call_log cl1
 INNER JOIN call_log cl2
 ON cl1.call_datetime
 BETWEEN cl2.call_datetime  AND ADDTIME(cl2.call_datetime, cl2.call_length)
 GROUP BY cl1.call_id) AS counts;

关于mysql - 从 call_log 中获取并发电话的最大数量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13322489/

文章推荐： Android闹钟广播/检测

文章推荐： iOS 推送通知仅显示角标(Badge)。也需要声音和横幅

mysql - 只有 Mysql OR mysql+sqlite OR mysql+自己的解决方案
目前我正在构建相当大的网络系统，我需要强大的 SQL 数据库解决方案。我选择 Mysql 而不是 Postgres，因为一些任务需要只读(MyISAM 引擎)而其他任务需要大量写入(InnoDB)。
mysql - Linux/mysql 将 mysql 表输出写入文件并保持 mysql 格式。
我在 mysql 中使用如下命令。当它显示表格数据时，它被格式化为一个非常干净的表格，间距均匀且 |作为列分隔符。 SELECT * FROM TABLE_NAME; 当我从 CLI 运行命令时，如下
mysql - 无法从终端加载 mysql 但可以使用系统首选项启动 mysql
我知道这个问题之前已经被问过好几次了，我已经解决了很多问题，但到目前为止没有任何效果。 MySQL 试图将自身安装到的目录 (usr/local/mysql) 肯定有问题。关于我的错误的奇怪之处在于我
mysql - 在 mysql 数据查询上获取不需要的输出 mysql
以下是我的 SQL 数据结构，我正在尝试如下两个查询: Select Wrk_ID, Wrk_LastName, Skill_Desc from Worker, Skill where
mysql - 将本地 mysql 服务器复制到基于云的 mysql
我们有一个本地 mysql 服务器(不在公共(public)域上)，并希望将该服务器复制到我们拥有的 google 云 sql 实例。我的问题是:1.这可能吗？2.我们的本地服务器只能在本地网络上访问
mysql - MySQL 触发器上 MySQL 变量的算术运算
我有一个表(test_table)，其中一些字段值(例如字段 A、B 和 C)是从外部应用程序插入的，还有一个字段(字段 D)，我想从现有表(store_table)插入其值，但在插入前者(A、B 和
mysql - 无法在创建 MySQL 服务器的同一计划中使用 mysql
我想创建一个 AWS RDS 实例，然后使用 terraform 管理数据库用户。因此，首先，我创建了一个 RDS 实例，然后使用创建的 RDS 实例初始化 mysql 提供程序，以进一步将其用于用户
mysql - MySql 用户数量对 MySql 性能影响大吗？
当用户在我的网站上注册时，他们会在我的一个数据库中创建自己的表格。该表存储用户发布的所有帖子。我还想做的是也为他们生成自己的 MySql 用户——该用户仅有权从他们的表中读取、写入和删除。创建它应该
mysql - mysql 表中的下和子类别(coldfusion，mysql)
我有一个关于 ColdFusion 和 Mysql 的问题。我有两个表:PRODUCT 和 PRODUCT_CAT。我想列出包含一些标记为:IS_EXTRANET=1 的特殊产品的类别。所以我写了这个
mysql - 如何使用 MYSQL 运算符选择列所有值都必须可用 - MYSQL
我想获取 recipes_id 列的值，以获取包含 ingredient_id 的 2,17 和 26 条目的值。假设 ingredient_id 2 丢失则不获取记录。我已经尝试过 IN 运算符
mysql - MySQL 服务器和 MySQL 客户端有什么区别
在 Ubuntu 中，我通常安装两者，但 MySQL 的客户端和服务器之间有什么区别。作为奖励，当一个新语句提到它需要 MySQL 5.x 时，它是指客户端、服务器还是两者兼而有之。例如这个链接ht
mysql - mysql - 如何在没有触发器和手动插入的情况下在插入时生成/自动增加 guid mysql？
我重新访问了我的数据库并注意到我有一些 INT 类型的主键。这还不够独特，所以我想我会有一个指导。我来自微软 sql 背景，在 ssms 中你可以选择类型为“uniqeidentifier”并自
mysql - Oracle MySQL 与 MySQL 相同吗？
我的系统上有 MySQL，我正在尝试确定它是 Oracle MySQL 还是 MySQL。 Oracle MySQL 有区别吗: http://www.oracle.com/us/products/m
mysql - 本地 mysql 服务器和生产 mysql 服务器之间的显着性能差异
我是在生产 MySQL 中运行的应用程序的新维护者。之前的维护者已经离开，留下的文档很少，而且联系不上了。我面临的问题是执行以下请求大约需要 10 秒: SELECT COUNT(*) FROM `
mysql - 如何自动将数据从一个 MySQL 数据库传输到另一个 MySQL 数据库？
我有两个位于不同机器上的 MySQL 数据库。我想自动将数据从一台服务器传输到另一台服务器。比方说，我希望每天早上 4:00 进行数据传输。可以吗？是否有任何 MySQL 内置功能可以让我们做到这一
mysql - 从 mysql 目录外的 mysql 表查询？
有什么方法可以使用 jdbc 查询位于 mysql 根目录之外的目录中的 mysql 表，还是必须将它们移动到 mysql 根目录内的数据库文件夹中？我在 Google 上搜索时没有找到任何东西。最
mysql - 使用另一个 mysql 表的值更新 Mysql 表
我在 mysql 数据库中有两个表。成员和 ClassNumbers。两个表都有一个付费年份字段，都有一个代码字段。我想用代码数字表中的值更新成员表中的付费年份，其中成员中的代码与 ClassNumb
mysql - 是否可以将本地 MySQL 数据库复制到远程 MySQL 数据库？
情况:我有 2 台服务器，其中一台当前托管一个实时 WordPress 站点，我希望能够将该站点转移到另一台服务器，以防第一台服务器出现故障。传输源文件很容易；传输数据库是我需要弄清楚如何做的。两台服
mysql - 使用 mysql 查询复制 mysql 数据库
Phpmyadmin 有一个功能是“复制数据库到”..有没有mysql查询来写这个函数？类似于将 db A 复制到新的 db B。最佳答案首先创建复制数据库: CREATE DATABASE du
mysql - 当 mySQL 已安装并由另一个应用程序配置时，为新应用程序配置 mySQL
我有一个使用 mySQL 作为后端的库存软件。我已经在我的计算机上对其进行了测试，并且运行良好。当我在计算机上安装我的软件时，我必须执行以下步骤: 安装 mySQL 服务器将用户名指定为“root

行者123

个人简介

我是一名优秀的程序员,十分优秀！

作者热门文章

滴滴打车优惠券免费领取

全站热门文章

首页

博学

6Ren·AI

商城

mysql - 从 call_log 中获取并发电话的最大数量