MQL，PHP是否从两个表中全部选择？

Question

So i have two tables:

order_product

--------------------------------------------------
| ProductID     | Quantity         
--------------------------------------------------

products

-------------------------------------------------------------
| ProductID     | productname | Desc | Price | Stock | Image     
------------------------------------------------------------

and i need to get all of the same product ID, show their quantity then times that by their price and show the grand total of all.

My problem is i'm trying to show a checkout page which shows everything in a list, but how do i combine the two tables? Also, there are no foreign keys for the first table.

I need this in an sql statement as well preferably, like:

$sql = 'SELECT...'

Would this work?

$sql = "SELECT * FROM order_products
UNION
SELECT * FROM products"

If so, how do i know which row is which?

My desired output is all entries, now looking like this:

ProductID     | Quantity   | Productname | Desc | Price | Stock | Image

Answer 1

You need a classical JOIN clause:

   SELECT * 
     FROM products
LEFT JOIN order_products on products.ProductId = order_products.ProductId

Answer 2

select table1.ProductID
     , table1.Quantity
     , table2.Productname
     , table2.Desc
     , table2.Price
     , table2.Stock
     , table2.Image 
FROM table1 
JOIN table2 ON table1.productid=table2.productid

Answer 3

My problem is i'm trying to show a checkout page which shows everything in a list, but how do i combine the two tables?

You need to simply use mysql JOIN to show cart items.

Your table data should be like as i added in demo.

See SQL Fiddle Demo

SELECT 
  o.id 'orderId',
  o.ProductID 'pid',
  SUM(o.Quantity) 'qty',
  p.productname  'product',
  p.`Price` 'price' 
FROM
  order_product o 
  INNER JOIN products p 
    ON p.`ProductID` = o.`ProductID` 

Edit Required output

My desired output is all entries, now looking like this:
ProductID | Quantity | Productname | Desc | Price | Stock | Image

Modify above query's SELECT part SELECT tablename.your_column .....

Answer 4

Not sure exactly what's the output you wish to get is but you should use something like this

SELECT o.ProductID, o.Quantity, p.Price, o.Quantity * p.Price
FROM order_product o
LEFT JOIN products p ON o.ProductID = p.ProductID

Answer 5

Use inner join.

Select * from order_products op INNER JOIN products p ON p.ProductID = op.ProductID;

wrt your need, the above query needs to be modified to:-

 "SELECT *,
         SUM(op.quantity * p.price) AS grandTotal
    FROM order_products op
    INNER JOIN PRODUCT p ON p.ProductID = op.ProductID WHERE p.ProductID =".$prodId(your php variable of product id);