我有桌子:
CREATE TABLE IF NOT EXISTS `buildingAccess` (
`id` int(10) unsigned NOT NULL,
`building` varchar(16) NOT NULL,
`person` varchar(16) NOT NULL,
`enteryDate` datetime NOT NULL,
`exitDate` datetime DEFAULT NULL
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;
INSERT INTO `buildingAccess` (`id`, `building`, `person`, `enteryDate`, `exitDate`) VALUES
(1, 'Lot B-3', 'Alice Jones', '2015-11-10 05:29:14', '2015-11-10 15:18:42'),
(3, 'Lot B-3', 'Alice Jones', '2015-11-11 07:11:27', '2015-11-11 12:43:34'),
(7, 'Lot B-3', 'Alice Jones', '2015-12-10 07:11:27', '2015-12-11 12:43:34'),
(2, 'Lot B-3', 'Bill Mayhew', '2015-11-10 10:29:14', '2015-11-10 12:18:42'),
(4, 'Lot B-3', 'Bill Mayhew', '2015-11-12 09:10:27', '2015-11-13 02:43:34'),
(8, 'Lot B-3', 'Bill Mayhew', '2015-11-12 09:10:27', '2015-11-13 02:43:34'),
(5, 'Lot B-3', 'Charlotte Ahn', '2015-12-01 05:29:14', NULL),
(6, 'Lot B-3', 'Dennis Lowe', '2015-12-10 10:29:14', '2015-12-10 12:18:42');
CREATE TABLE IF NOT EXISTS `buildingNotes` (
`building` varchar(16) NOT NULL,
`observer` varchar(16) NOT NULL,
`observationDate` datetime NOT NULL,
`note` varchar(64) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
INSERT INTO `buildingNotes` (`building`, `observer`, `observationDate`, `note`) VALUES
('Lot B-3', 'Alice Jones', '2015-11-10 05:32:12', 'burned out light on pole South-22'),
('Lot B-3', 'Alice Jones', '2015-11-10 05:39:12', 'burned out light on pole West-7'),
('Lot B-3', 'Alice Jones', '2015-11-10 05:42:12', 'overfull trash can near pole North-11'),
('Lot B-3', 'Charlotte Ahn', '2015-12-01 06:09:14', 'change drawr running low at gate 3');
ALTER TABLE `buildingAccess`
ADD PRIMARY KEY (`id`), ADD KEY `building` (`building`,`person`,`enteryDate`,`exitDate`);
ALTER TABLE `buildingNotes`
ADD KEY `building` (`building`,`observer`,`observationDate`,`note`);
ALTER TABLE `buildingAccess`
MODIFY `id` int(10) unsigned NOT NULL AUTO_INCREMENT,AUTO_INCREMENT=9;
我的目标是一个查询,它返回buildingAccess
表中所有记录的列表。每个字段都应有一个notes
字段,该字段是GROUP_CONCAT
中buildingNotes.note
条记录的所有buildingAccess.enteryDate
条目,buildingAccess.exitDate
日期/时间由 select
BA.building,
BA.person,
BA.enteryDate,
IFNULL(BA.exitDate, NOW()),
IFNULL(
GROUP_CONCAT(
'<p>',
BN.observationDate, ': ',
BN.observer, ': ', BN.note,
'</p>'
ORDER BY BN.observationDate ASC
SEPARATOR ''
),
''
)
from
buildingAccess BA
LEFT JOIN buildingNotes BN ON
BN.building = BA.building
AND BN.observationDate BETWEEN BA.enteryDate AND BA.exitDate
group by BN.building
和{{1}括起来}}
我尝试了一些事情,但我坚持:
+----------+---------------+---------------------+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| building | person | enteryDate | exitDate | observations |
+----------+---------------+---------------------+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Lot B-3 | Charlotte Ahn | 2015-12-01 05:29:14 | 2016-01-23 23:04:04 | |
| Lot B-3 | Alice Jones | 2015-11-10 05:29:14 | 2015-11-10 15:18:42 | <p>2015-11-10 05:32:12: Alice Jones: burned out light on pole South-22</p><p>2015-11-10 05:39:12: Alice Jones: burned out light on pole West-7</p><p>2015-11-10 05:42:12: Alice Jones: overfull trash can near pole North-11</p> |
+----------+---------------+---------------------+---------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
返回:
buildingAccess
即使没有buildingNotes
条记录,我也希望看到所有其他<form action="/NewCases/" method=post class="form-horizontal">
<h2>Add New Cases: </h2>
<div class="input-group">
<span class="input-group-addon">@</span>
<input type="text" id="casename" name="casename" class="form-control"
placeholder="Enter Case Name:" required>
</div>
<div class="input-group">
<span class="input-group-addon">@</span>
<input type="text" id="adminname" name="adminname" class="form-control"
placeholder="Enter Case Name:" value="{{ current_user.username }}">
</div>
<div class="input-group">
<span class="input-group-addon">@</span>
<input type="file" id="imagefile" name="imagefile" class="form-control"
placeholder="Enter Hard Disk File:" required>
</div>
<div class="input-group">
<span class="input-group-addon">@</span>
<input type="file" id="memimagefile" name="memimagefile" class="form-control"
placeholder="Enter Memory File:" required>
</div>
<div class="control-group">
<div class="controls">
<button type="submit" class="btn btn-success">Signup</button>
</div>
</div>
</form>
条记录。
我假设我不是&#34;按&#34;分组正确的事情,但我还没有找到合适的组合。
指针?
答案 0 :(得分:1)
我认为这是因为使用了来自GROUP BY子句中的外连接表的BN.building。请尝试以下方法:
SELECT
BA.building
, BA.person
, BA.enteryDate
, IFNULL(BA.exitDate, NOW())
, IFNULL (
GROUP_CONCAT (
'<p>',
BN.observationDate, ': ',
BN.observer, ': ', BN.note,
'</p>'
ORDER BY BN.observationDate ASC
SEPARATOR ''
)
,''
)
FROM buildingAccess BA
LEFT JOIN buildingNotes BN ON BN.building = BA.building
AND BN.observationDate BETWEEN BA.enteryDate AND BA.exitDate
GROUP BY
BA.building
, BA.person
, BA.enteryDate
, IFNULL(BA.exitDate, NOW())
这可能是行太多,也许您需要一些其他方式来处理(例如)只获取日期而不是完整的日期时间。但是,您应该通过caluse定期指定组中查询的所有非聚合列。见MySQL GROUP BY Extension