INNER and LEFT JOIN on mysql -

i have needing chain joins queries, , not able result want.
have many tables save product info:

-products: name , description in many languages.

-products_attributes: common attributes of products provider or buying price.

-products_locations: info concerning locations sell product, stock, or selling price.

-other important table companies one: of companies provider.

well, query:

select p.id      , p.name nameproduct      , p.reference refproduct      , a.buy_price priceproduct      , l.active      , l.sell_price      , l.stock stockproduct      , c.title p_name   products p   left join products_location l     on l.product_reference = p.reference     , l.active = 1     , l.location_id = 4    join products_attributes     on a.product_reference = p.reference     , p.lang = 'es'     , a.provider = 6   join companies c     on a.provider = c.id     , c.id = 6 

what want products of provider, if location executing query has product, row of result must return concerning @ product<->location, in contrary must return null in column related relation.
@ moment, query, getting products of provider has relation between product<->location (through products_location table).

any way that??

thank you.

edit

an example trying this:

table: companies

id | title  1  | somename 6  | providername 

table: products

id | reference | name | lang 1  | 11111     | 1_es | es 2  | 11111     | 1_en | en 3  | 22222     | 2nam | es 4  | 33333     | 3nam | es 5  | 44444     | 4nam | es 6  | 55555     | 5nam | es 

table: products_atributte

id | product_reference | buy_price | provider 1  | 11111             | 10        | 6 1  | 22222             | 15        | 6 1  | 33333             | 20        | 6 1  | 44444             | 12        | 1 1  | 55555             | 13        | 1 

table: products_locations

id | product_reference | location_id | sell_price | stock | active 1  | 11111             | 4           | 26          | 10    | 1 1  | 11111             | 5           | 25          | 13    | 1 1  | 22222             | 5           | 20          | 13    | 1 1  | 44444             | 5           | 21          |  1    | 1 1  | 55555             | 5           | 22          |  2    | 1 

and result must this:

nameproduct | refproduct | priceproduct | active | sell_price | stockproduct | p_name 1_es        | 11111      | 10           | 1      | 26         | 10           | providername 2nam        | 22222      | 15           | null   | null       | null         | providername 3nam        | 33333      | 20           | null   | null       | null         | providername 

if use left join in products_locations table, don´t 2 last rows, , if use left join tables duplicates product references, products provided other providers (in example 1-> somename).

you correct left join products , products_location tables. however, used inner join other 2 tables in query , believe may reason why seeing records have relation between product , location. logic product not have location also not have entry in, example, products_attributes table. hence, non matching records want retain filtered off downstream inner join. remedy this, use left join everywhere:

select products.id,        products.name nameproduct,        products.reference refproduct,        products_attributesbuy_price priceproduct,        products_location.active,        products_location.sell_price,        products_location.stock stockproduct,        provider.title p_name products left join products_location     on products_location.product_reference = products.reference ,        products_location.active = 1 ,        products_location.location_id = 4 left join products_attributes     on products_attributes.product_reference = products.reference ,        products.lang = 'es' ,        products_attributes.provider = 6 left join companies provider     on products_attributes.provider = provider.id ,        provider.id = 6