我真的对数据透视表感到困惑,请看看我有什么以及我需要实现什么:
这是我的mysql表结构
id meta_value field_id item_id
1 Ankur Fname 1
2 Gupta Lname 1
3 AAS Holdings Company 1
4 Christie Fname 2
5 Trojillo Lname 2
6 AWS Company 2
7 Devadanam Fname 3
8 Pulukuri Lname 3
9 AAS Holdings Company 3
10 Radha Fname 4
11 Neupane Lname 4
......> There is no "Company" for that person
12 Marites Fname 5
13 Torsar Lname 5
14 AAS Holdings Company 5
15 Muthanna Fname 6
16 Shareef Lname 6
17 GFTC Company 6
我需要能够以这种方式使用 php mysql 在 HTML 表格中呈现数据
First Name Last Name Company
Ankur Gupta ASS Holdings
Christie Trojillo AWS
例如,我还需要能够按公司对该表进行排序。
这是我尝试做的,但我知道这是完全错误的,因为数据库可能只有 Fname 和 Lname 而没有公司,这将导致转义并使用下一个值并破坏表格,而且数据可以存储顺序不同
$sql="SELECT * FROM system_frm_item_metas ORDER BY item_id";
$result=mysqli_query($con,$sql);
if ($result->num_rows > 0) {
echo "<table><tr><th>First Name</th><th>Last Name</th><th>Company</th></tr>";
while($row = $result->fetch_assoc()) {
if ($row["field_id"] == "Fname") { echo "<tr><td>".$row["meta_value"]."</td>";}
if ($row["field_id"] == "Lname") { echo "<td>".$row["meta_value"]."</td>";}
if ($row["field_id"] == "Company") { echo "<td>".$row["meta_value"]."</td></tr>";}
}
echo "</table>";
我们将不胜感激
最佳答案
DROP TABLE IF EXISTS eav_hell;
CREATE TABLE eav_hell
(entity INT NOT NULL
,attribute VARCHAR(12) NOT NULL
,value VARCHAR(30) NOT NULL
,PRIMARY KEY(entity,attribute)
);
INSERT INTO eav_hell VALUES
(1 ,'Fname','Ankur'),
(1 ,'Lname','Gupta'),
(1 ,'Company','AAS Holdings'),
(2 ,'Fname','Christie'),
(2 ,'Lname','Trojillo'),
(2 ,'Company','AWS'),
(3 ,'Fname','Devadanam'),
(3 ,'Lname','Pulukuri'),
(3 ,'Company','AAS Holdings'),
(4 ,'Fname','Radha'),
(4 ,'Lname','Neupane'),
(5 ,'Fname','Marites'),
(5 ,'Lname','Torsar'),
(5 ,'Company','AAS Holdings'),
(6 ,'Fname','Muthanna'),
(6 ,'Lname','Shareef'),
(6 ,'Company','GFTC');
SELECT entity
, MAX(CASE WHEN attribute = 'Fname' THEN value END) Fname
, MAX(CASE WHEN attribute = 'Lname' THEN value END) Lname
, MAX(CASE WHEN attribute = 'Company' THEN value END) Company
FROM eav_hell
GROUP
BY entity;
+--------+-----------+----------+--------------+
| entity | Fname | Lname | Company |
+--------+-----------+----------+--------------+
| 1 | Ankur | Gupta | AAS Holdings |
| 2 | Christie | Trojillo | AWS |
| 3 | Devadanam | Pulukuri | AAS Holdings |
| 4 | Radha | Neupane | NULL |
| 5 | Marites | Torsar | AAS Holdings |
| 6 | Muthanna | Shareef | GFTC |
+--------+-----------+----------+--------------+
或(更快但不够优雅)...
SELECT DISTINCT e.entity
, f.value fname
, l.value lname
, c.value company
FROM eav_hell e
LEFT
JOIN eav_hell f
ON f.entity = e.entity
AND f.attribute = 'fname'
LEFT
JOIN eav_hell l
ON l.entity = e.entity
AND l.attribute = 'lname'
LEFT
JOIN eav_hell c
ON c.entity = e.entity
AND c.attribute = 'company';
关于php - 从数据透视表(垂直 mysql 表)查看数据,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27820670/