MySQL/PHP, getting all the data in one go - php

Question

I have a database with three tables:
Products
MaterialsProducts
Materials
The relationship between the tables are like this:
Materials 1-* MaterialsProducts *-1 Products
Quite often I need to retrieve 200+ products and their related material data (from the Materials table).
Currently it is done like this:
SQL: select all relevant products
PHP: iterate through the selected products, calling the database to select material data for each product(generating a database call for each product!)
Is there a way to select all relevant products + their material data at the same time? And still have each product only take up one row in the result.
So the solution shouldn't be "SELECT * FROM products p, materialsproducts mp, materials m WHERE p.id = mp.productid AND m.id = mp.materialid WHERE x". (That SELECT would make each product take up more than one row in the result.)

Answer 1

you can use left join to get all data you need
documentation here
Your query have a mistake
"SELECT * FROM `products` p LEFT JOIN `materialsproducts` mp on p.`id` = mp.`productid` LEFT JOIN `materials` m ON m.`id` = mp.`materialid` WHERE $whateveryouneed"
remember to not limit your WHERE to only 1 ID otherwise you will need more queries.
UPDATED
as asked
products has a 1-* relationship with both materialsproducts and typesproducts. materialsproducts has a *-1 relationship with materials. typesproducts has a *-1 relationship with types.
So you can make a left join query as above in this way
SELECT * FROM `products` p
LEFT JOIN `materialsproducts` mp
ON p.`id` = mp.`productid`
LEFT JOIN `materials` m
ON mp.`mp_field_id_here` = m.`m_field_id_here` //here you need to change with actual field to compare
LEFT JOIN `typesproducts` tp
ON p.`id` = tp.`tp_field_id_here` //here you need to change with actual field to compare
LEFT JOIN `types` t
ON tp.`tp_field_id_here` = t.`t_field_id_here` //here you need to change with actual field to compare
then you can add a where statment to limit result to something that suits you
WHERE WHATEVER_YOU_NEED
UPDATED AGAIN
to limit result to only some filed just change * to something specific as
"SELECT p.`Product_Name`, m.`Material_1`, m.`Material_2, m.`Material_3`, t.`Type_1`, t.`Type_2` FROM .....
NOTE I assume you retrieve material 1, material 2, material 3 from material table wich is why i used as prefix m. Either way i used as prefix t for type 1 and type 2 because i thought they are fileds of type table, otherwise you can change them according to your needs.

Answer 2

Try
SELECT p.*, mp.*,m.*
FROM products p
JOIN materials m ON p.id=m.prd_id
JOIN materialsproducts mp ON m.mp_id=mp.id;

Answer 3

It is not simple to have a query like this compress the materials data into a single row for each product - so I don't think that plan will work well for you.
What I would recommend instead is to use a normal JOIN query (much like the one you put in your question and rejected), then use PHP code to deal with the cases where a single product has multiple rows in the result set because it is linked to multiple materials.

Answer 4

You could use GROUP_CONCAT to combine materials related to the same product into a single list while grouping by products:
SELECT
p.ProductID,
p.ProductName,
GROUP_CONCAT(m.MaterialName) AS Materials
FROM Products p
INNER JOIN MaterialsProducts mp ON p.ProductID = mp.ProductID
INNER JOIN Materials m ON m.MaterialID = mp.MaterialID
GROUP BY
p.ProductID,
p.ProductName
;