使用鍵/值對過濾和分組來自表的數據

Question

我很努力從數據收集環境的CSV風格數據的「規範化」數據庫中提取數據。這將使用PHP/MySQL/JSON完成，目的是繪製數據。我認爲我有過濾部分，但我需要幫助進行旋轉。這個想法是使用keyNames字段作爲數據的過濾器。

下面是查詢：

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'); 

和結果：

+--------+-------+-------------+----------+ 
| 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 | 
+--------+-------+-------------+----------+ 

我想樞轉進入該：testId，ROWID，電壓，溫度，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？我覺得我接近這一點：

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 | 
+--------+-------+---------+-------------+----------+ 

下面是引用表的定義和數據源：

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

你的問題的部分原因是你在SELECT列表中使用聚合函數但你沒有使用GROUP BY。您應該使用一個GROUP BY與此類似：

GROUP BY d.testId, d.rowId 

每當你使用聚合函數，你必須在你的選擇等欄目，他們應該是一組分析研究。因此，您的完整查詢應該是：

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 

請注意，雖然您的實際數據結構未顯示在原始問題中。看起來，這可以合併到以下內容：

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 

請參閱SQL Fiddle with Demo。這給出了data表中只有一個連接的結果：

| 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 |