从多个表中获取数据

Question

I need to get data from multiple tables and put it into a subform.

The SubForm columns are 'product name' and 'quantity' and they need to list out the products relating to the order ID.

The tables in question are:

PRODUCTS(productID,productName)

ORDER(orderID,prodID,quantity)

Where the prodID in ORDER refers to the PRODUCTS table.

As you can see, the problem is that the name of the product is in a different table to the order. So, the data I need to get is:

Products(productName)

Order(quantity)

In relation to the orderID .

How can I use a SQL query to get this data? I am aware of joins and so on, but I just can't see how to apply it.

Thank you. I hope this makes sense.

Answer 1

This is a simple inner join between the two tables to return the rows you want:

SELECT P.PRODUCTNAME, O.QUANTITY
FROM PRODUCTS P INNER JOIN ORDER O ON P.PRODUCTID = O.PRODID
WHERE O.ORDERID = <order id>

Answer 2

SELECT
  PRODUCTS.productName AS productName,
  `ORDER`.quantity AS quantity
FROM
  `ORDER`
  INNER JOIN PRODUCTS on `ORDER`.prodID=PRODUCTS.productID
WHERE
 ..

You migh also want to rename the table ORDER - using reserved words as table names is not the best of styles.

Answer 3

从product_table p，quantity_table q中选择p.productname，q.quantity，其中p.productId = q.productId;