How to go about this implementation of query - sql

Question

My database table are as follow
CREATE TABLE [dbo].[vProduct](
[nId] [int] NOT NULL, //Primary key
[sName] [varchar](255) NULL
)
CREATE TABLE [dbo].[vProductLanguage](
[kProduct] [int] NOT NULL,
[kLanguage] [int] NOT NULL //Foriegn key to table vLanguage
)
CREATE TABLE [dbo].[vLanguage](
[nId] [int] NOT NULL, //Primary key
[sName] [varchar](50) NULL,
[language] [char](2) NULL
)
Table vProduct has relation to vProductLanguage on vProduct.nId = vProductLanguage.kLanguage
Table vProductLanguage has relation to vLanguage on vProductLanguage.kLanguage = vLanguage.nid
So its like table vProductLanguage will have languages which are being selected
Rows will be like image below
Table vProduct
Table vProductLanguage
Table vLanguage
What i want is select all Languages from table vLanguage and selected languages from table vProductLanguage. This will be associated with table vProduct.
I tried below query but it only returns me the languages which are associated with product.
select * from
vProductLanguage
left join vLanguage on vProductLanguage.kLanguage = vLanguage.nId
left join vProduct on vProductLanguage.kProduct = vProduct.nId
Where vProduct.nId = 1
I want to select all the rows from table vLanguage and table vProductLanguage.
Hope i made my question clear.

Answer 1

It sounds like you want to start your JOIN with the vLanguage table first:
select *
from vLanguage l
left join vProductLanguage pl
on l.nid = pl.kLanguage
left join vProduct p
on pl.kProduct = p.nid
and p.nid = 1
See SQL Fiddle with Demo.
This will return all rows from the vLanguage table and any matching rows from the vProductLanguage table. .
If you have more than one vProduct then you can rewrite the query slightly to:
select *
from vLanguage l
left join
(
select pl.kLanguage,
p.nid,
p.sName
from vProductLanguage pl
left join vProduct p
on pl.kProduct = p.nid
where p.nid = 1
) p
on l.nid = p.kLanguage
See SQL Fiddle with Demo