使用键/值对过滤和分组来自表的数据

Question

我很努力从数据收集环境的CSV风格数据的“规范化”数据库中提取数据。这将使用PHP/MySQL/JSON完成，目的是绘制数据。我认为我有过滤部分，但我需要帮助进行旋转。这个想法是使用keyNames字段作为数据的过滤器。

下面是查询：

select d.testId,d.rowId,f.keyName,f.keyValue from tests t 
inner join data d on t.testId = d.testId 
inner join data c on t.testId = c.testId and c.rowId = d.rowId 
join data f on f.testId = t.testId and f.rowId = d.rowId 
where (d.keyName = 'voltage' and d.keyValue < 5) and (c.keyName = 'temperature' and c.keyValue = 30) and (t.testType = 'testType1'); 

和结果：

+--------+-------+-------------+----------+ 
| testId | rowId | keyName  | keyValue | 
+--------+-------+-------------+----------+ 
|  1 |  1 | voltage  |  4 | 
|  1 |  1 | temperature |  30 | 
|  1 |  1 | velocity |  20 | 
|  1 |  2 | voltage  |  4 | 
|  1 |  2 | temperature |  30 | 
|  1 |  2 | velocity |  21 | 
|  2 |  1 | voltage  |  4 | 
|  2 |  1 | temperature |  30 | 
|  2 |  1 | velocity |  30 | 
|  2 |  2 | voltage  |  4 | 
|  2 |  2 | temperature |  30 | 
|  2 |  2 | velocity |  31 | 
+--------+-------+-------------+----------+ 

我想枢转进入该：testId，ROWID，电压，温度，速度，如：

+--------+-------+---------+-------------+----------+ 
| testId | rowId | voltage | temperature | velocity | 
+--------+-------+---------+-------------+----------+ 
|  1 |  1 |  4 |   30 |  20 | 
|  1 |  2 |  4 |   30 |  21 | 
|  2 |  1 |  4 |   30 |  30 | 
|  2 |  2 |  4 |   30 |  31 | 
+--------+-------+---------+-------------+----------+ 

任何想法？我觉得我接近这一点：

mysql> select f.testId,f.rowId,(if(f.keyName='voltage',f.keyValue,NULL)) as 'voltage',(if(f.keyName='temperature',f.keyValue,NULL)) as 'temperature',(if(f.keyName='velocity',f.keyValue,NULL)) as 'velocity' from tests t inner join data d on t.testId = d.testId inner join data c on t.testId = c.testId and c.rowId = d.rowId join data f on f.testId = t.testId and f.rowId = d.rowId where (d.keyName = 'voltage' and d.keyValue < 5) and (c.keyName = 'temperature' and c.keyValue = 30) and (t.testType = 'testType1'); 
+--------+-------+---------+-------------+----------+ 
| testId | rowId | voltage | temperature | velocity | 
+--------+-------+---------+-------------+----------+ 
|  1 |  1 |  4 |  NULL |  NULL | 
|  1 |  1 | NULL |   30 |  NULL | 
|  1 |  1 | NULL |  NULL |  20 | 
|  1 |  2 |  4 |  NULL |  NULL | 
|  1 |  2 | NULL |   30 |  NULL | 
|  1 |  2 | NULL |  NULL |  21 | 
|  2 |  1 |  4 |  NULL |  NULL | 
|  2 |  1 | NULL |   30 |  NULL | 
|  2 |  1 | NULL |  NULL |  30 | 
|  2 |  2 |  4 |  NULL |  NULL | 
|  2 |  2 | NULL |   30 |  NULL | 
|  2 |  2 | NULL |  NULL |  31 | 
+--------+-------+---------+-------------+----------+ 

下面是引用表的定义和数据源：

CREATE TABLE IF NOT EXISTS `data` (
    `ptId` int(11) NOT NULL AUTO_INCREMENT, 
    `testId` int(11) NOT NULL, 
    `rowId` int(11) NOT NULL, 
    `keyName` text NOT NULL, 
    `keyValue` int(11) NOT NULL, 
    PRIMARY KEY (`ptId`) 
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=33 ; 

INSERT INTO `data` (`ptId`, `testId`, `rowId`, `keyName`, `keyValue`) VALUES 
(1, 1, 1, 'voltage', 4), 
(2, 1, 1, 'temperature', 30), 
(3, 1, 1, 'velocity', 20), 
(4, 1, 2, 'voltage', 4), 
(5, 1, 2, 'temperature', 30), 
(6, 1, 2, 'velocity', 21), 
(7, 1, 3, 'voltage', 3), 
(8, 1, 3, 'temperature', 35), 
(9, 1, 3, 'velocity', 22), 
(10, 1, 4, 'voltage', 3), 
(11, 1, 4, 'temperature', 35), 
(12, 1, 4, 'velocity', 23), 
(13, 2, 1, 'voltage', 4), 
(14, 2, 1, 'temperature', 30), 
(15, 2, 1, 'velocity', 30), 
(16, 2, 2, 'voltage', 4), 
(17, 2, 2, 'temperature', 30), 
(18, 2, 2, 'velocity', 31), 
(19, 2, 3, 'voltage', 5), 
(20, 2, 3, 'temperature', 35), 
(21, 2, 3, 'velocity', 32), 
(22, 2, 4, 'voltage', 5), 
(23, 2, 4, 'temperature', 35), 
(24, 2, 4, 'velocity', 33), 
(25, 4, 1, 'voltage', 4), 
(26, 4, 1, 'velocity', 30), 
(27, 4, 2, 'voltage', 4), 
(28, 4, 2, 'velocity', 31), 
(29, 4, 3, 'voltage', 5), 
(30, 4, 3, 'velocity', 32), 
(31, 4, 4, 'voltage', 5), 
(32, 4, 4, 'velocity', 33); 

CREATE TABLE IF NOT EXISTS `tests` (
    `testId` int(11) NOT NULL AUTO_INCREMENT COMMENT 'Unique Test ID', 
    `testType` text NOT NULL, 
    `startDate` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, 
    `userName` text NOT NULL, 
    `testSoftware` text NOT NULL, 
    `comments` text, 
    `dutID` text, 
    PRIMARY KEY (`testId`) 
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=8 ; 

INSERT INTO `tests` (`testId`, `testType`, `startDate`, `userName`, `testSoftware`, `comments`, `dutID`) VALUES 
(1, 'testType1', '2013-03-23 21:06:10', 'testUser1', 'testSoftware1', NULL, 'dut1'), 
(2, 'testType1', '2013-03-23 21:10:32', 'testUser1', 'testSoftware1', NULL, 'dut1'), 
(3, 'testType1', '2013-03-23 21:10:32', 'testUser1', 'testSoftware1', NULL, 'dut1'), 
(4, 'testType2', '2013-03-23 21:10:32', 'testUser1', 'testSoftware1', NULL, 'dut1'); 

Answer 1

你的问题的部分原因是你在SELECT列表中使用聚合函数但你没有使用GROUP BY。您应该使用一个GROUP BY与此类似：

GROUP BY d.testId, d.rowId 

每当你使用聚合函数，你必须在你的选择等栏目，他们应该是一组分析研究。因此，您的完整查询应该是：

select d.testId, 
    d.rowId, 
    max(if(f.keyName='voltage',f.keyValue,NULL)) as 'voltage', 
    max(if(f.keyName='temperature',f.keyValue,NULL)) as 'temperature', 
    max(if(f.keyName='velocity',f.keyValue,NULL)) as 'velocity' 
from tests t 
inner join data d 
    on t.testId = d.testId 
inner join data c 
    on t.testId = c.testId 
    and c.rowId = d.rowId 
join data f 
    on f.testId = t.testId 
    and f.rowId = d.rowId 
where (d.keyName = 'voltage' and d.keyValue < 5) 
    and (c.keyName = 'temperature' and c.keyValue = 30) 
    and (t.testType = 'testType1') 
GROUP BY d.testId, d.rowId 

请注意，虽然您的实际数据结构未显示在原始问题中。看起来，这可以合并到以下内容：

select d.testid, 
    d.rowid, 
    max(case when d.keyName = 'voltage' and d.keyValue < 5 then d.keyValue end) voltage, 
    max(case when d.keyName = 'temperature' and d.keyValue =30 then d.keyValue end) temperature, 
    max(case when d.keyName = 'velocity' then d.keyValue end) velocity 
from tests t 
left join data d 
    on t.testid = d.testid 
group by d.testid, d.rowid 

请参阅SQL Fiddle with Demo。这给出了data表中只有一个连接的结果：

| TESTID | ROWID | VOLTAGE | TEMPERATURE | VELOCITY | 
----------------------------------------------------- 
|  1 |  1 |  4 |   30 |  20 | 
|  1 |  2 |  4 |   30 |  21 | 
|  2 |  1 |  4 |   30 |  30 | 
|  2 |  2 |  4 |   30 |  31 |