我需要一个小帮助来对项目ID进行分组和求和。
数据库中的数据:
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"];
}
一个例子:如果我在2个仓库上有相同的代码,那么它只获得其中的1个,我想要的是按product_id对数量和组进行求和。
感谢任何帮助。
答案 0 :(得分:2)
试试这个:
'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foreach
:
echo $row["code"] . ' ' . $row["sum_quantity"];
答案 1 :(得分:0)
查询:
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
PHP:
$db = new PDO('mysql:host=localhost;dbname=data2;charset=utf8', 'user2', 'Password');
foreach($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"];
}
请记住,我们依赖于产品表中的代码和ID是唯一对的事实。