CODEWITHSUNDEEP
mysqlrdbms
Panda Surya
Panda Surya

Reputation: 11

How to select and count data from three tables in mysql

I have three tables

1 - Products 
2- Orders
3- Order_item

Table (Products)

ID | Product_name | 
--------------------
1  | Samsung Galaxy

Table (Orders)

ID | Client_name 
-------------------
1  | Admin

Table (Orders_item) 

ID | Order_ID | Product_ID | Quantity 
-------------------------------------
1  | 1        | 1          | 1

2  | 1        | 1          | 1 

3  | 1        | 1          | 1

I want to select product name , client name and number of quantities when order is 1. I have tried this query

SELECT products.name,orders.order_id,orders.client_name,order_item.quantity COUNT(*) FROM products,orders,order_item WHERE products.id = order_item.product_id AND orders.order_id = order_item.order_id AND orders.order_id=1

Which returns result like 

Name | Order_ID | Client_name | Quantity 
----------------------------------------
Sa..| 1         | Admin       | 1 
Sa..| 1         | Admin       | 1 
Sa..| 1         | Admin       | 1

I want to get the the result like 

Samsung | 1 | Admin | 3

Someone please help me .

Upvotes: 0

Views: 38

Answers (1)

Cid
Cid

Reputation: 15247

You need a GROUP BY

SELECT products.Product_name AS Name,
       orders.id AS Order_ID,
       orders.client_name AS Client_name,
       SUM(order_item.Quantity) AS Quantity
FROM products
LEFT JOIN order_item 
ON order_item.Product_ID = products.ID
LEFT JOIN orders
ON orders.ID = order_item.Order_ID
WHERE orders.id=1
GROUP BY products.Product_name,
         orders.id,
         orders.client_name

This outputs :

| Name           | Order_ID | Client_name | Quantity |
| -------------- | -------- | ----------- | -------- |
| Samsung Galaxy | 1        | Admin       | 3        |

Note that JOIN can be a good reading too.

Upvotes: 1

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