基本的SQL查詢設計問題

Question

我想創建一個查詢，基本上是這個（不起作用）的equivelant。

SELECT * FROM `categories` AS C AND 
SELECT * FROM `items` AS I AND 
SELECT COUNT(I.id) AS items AND 
SELECT SUM(I.price) AS price; 

我沒有使用SQLServer，而是通過PHP使用PDO進行數據庫連接。

這是表格。

類別

+----+------------+ 
| id | Category | 
+----+------------+ 
| 1 | First_Cat | 
| 2 | Second_Cat | 
+----+------------+ 

項目

+----+----------+------+-------+ 
| id | category | name | price | 
+----+----------+------+-------+ 
| 1 |  1 | Foo | 1.99 | 
| 2 |  1 | Bar | 2.00 | 
| 3 |  2 | ooF | 0.99 | 
| 4 |  2 | raB | 1.99 | 
+----+----------+------+-------+ 

基於這些表我會期待這些查詢結果：

+----+------------+-------+-------+--+ 
| id | category | items | price | | 
+----+------------+-------+-------+--+ 
| 1 | First_Cat |  2 | 3.99 | | 
| 2 | Second_Cat |  2 | 2.98 | | 
+----+------------+-------+-------+--+ 

任何幫助？

Answer 1

您在評論中發佈的查詢中未加入類別表和項目表的查詢。這讓我覺得你可以做這樣的事情嗎？：

SELECT 
    categories.id, 
    categories.Category, 
    COUNT(*) AS items, 
    SUM(items.price) as price 
FROM 
    `categories` 
    JOIN items 
     ON categories.id = items.category 
GROUP BY 
    categories.id, 
    categories.Category