Php SQL从表sum和group by id中选择*

我需要一个小的帮助来分组和合计项目id的数量

来自数据库的数据：

products
id  code    name            price
1   1234    Product name    12
2   1235    Product name    12
3   1236    Product name    12

warehouses_products
product_id   warehouse_id   quantity
1           1               12
2           1               0
2           2               3
3           1               1
3           2               1

PHP获取数据

$db = new PDO('mysql:host=localhost;dbname=data2;charset=utf8', 'user2', 'Password');

foreach($db->query('SELECT * FROM products as pr INNER JOIN warehouses_products AS s ON (s.product_id = pr.id) group by pr.id') as $row) {
echo $row["code"] . ' ' . $row["quantity"];
}

举个例子：如果我在两个仓库上有相同的代码，这只能得到其中的一个，我想要的是按产品id对数量和组进行求和

感谢您的帮助。

尝试以下方法：

'SELECT *, SUM(s.quantity) AS sum_quantity FROM products as pr INNER JOIN warehouses_products AS s ON (s.product_id = pr.id) group by pr.id'

在您的

foreach

中：

echo $row["code"] . ' ' . $row["sum_quantity"];

查询：

PHP:

---

请记住，我们所依赖的事实是产品表中的代码和id是唯一的一对

谢谢@Prasanth，这就是解决方案。@Dario：在堆栈溢出中，我们接受答案来表示感谢：）

SELECT p.id, p.code, SUM(wp.quantity) as quantity
FROM products p
JOIN warehouses_products wp ON wp.product_id = p.id
GROUP BY p.id, p.code

$db = new PDO('mysql:host=localhost;dbname=data2;charset=utf8', 'user2', 'Password');

foreach($db->query('SELECT p.id, p.code, SUM(wp.quantity) as quantity FROM products p JOIN warehouses_products wp ON wp.product_id = p.id GROUP BY p.id, p.code') as $row) {
echo $row["code"] . ' ' . $row["quantity"];
}