Question

In a setup that has several one-to-many relationships of objects, and each using a name attribute coming from a separate table. For example

Building(BuildingName), Floor(FloorName)

If a building has 2 names (2 languageIDs) and 5 floors, where only 3 floors have names for both language IDs, I want still to have 10 resulting entries. The floor names, where they are missing when the language id is missing, being pulled(defaulted) from non-matching floor id.

Answer 1

Is this along the right lines for what you’re after?

Runnable example here: http://sqlfiddle.com/#!3/894e9/4

if object_id('[FloorName]') is not null drop table [FloorName]
if object_id('[BuildingName]') is not null drop table [BuildingName]
if object_id('[Floor]') is not null drop table [Floor]
if object_id('[Building]') is not null drop table [Building]
if object_id('[Language]') is not null drop table [Language]

create table [Language]
(
    Id bigint not null identity(1,1) primary key clustered
    , code nvarchar(5)
)
create table [Building]
(
    Id bigint not null identity(1,1) primary key clustered
    , something nvarchar(64)
)
create table [Floor]
(
    Id bigint not null identity(1,1) primary key clustered
    , BuildingId bigint foreign key references [Building](Id)
    , something nvarchar(64)
)
create table [BuildingName]
(
    Id bigint not null identity(1,1) primary key clustered
    , BuildingId bigint foreign key references [Building](Id)
    , LanguageId bigint foreign key references [Language](Id)
    , name nvarchar(64)
)
create table [FloorName]
(
    Id bigint not null identity(1,1) primary key clustered
    , FloorId bigint foreign key references [Floor](Id)
    , LanguageId bigint foreign key references [Language](Id)
    , name nvarchar(64)
)

insert [Language]
      select 'en-us'
union select 'en-gb'
union select 'fr'

insert [Building]
      select 'B1'
union select 'B2'

insert [Floor]
      select 1, 'F1.1'
union select 1, 'F1.2'
union select 1, 'F1.3'
union select 1, 'F1.4'
union select 1, 'F1.5'
union select 2, 'F2.1'
union select 2, 'F2.2'
union select 2, 'F2.3'
union select 2, 'F2.4'
union select 2, 'F2.5'

insert BuildingName
select b.Id
, l.id
, 'BuildingName :: ' + b.something + ' ' + l.code
from [Building] b
cross join [Language] l
where l.code in ('en-us', 'fr')

insert FloorName
select f.Id
, l.Id
, 'FloorName :: ' + f.something + ' ' + l.code
from [Floor] f
cross join [Language] l
where f.something in ( 'F1.1', 'F1.2', 'F2.1')
and l.code in ('en-us', 'fr')

insert FloorName
select  f.Id
, l.Id
, 'FloorName :: ' + f.something + ' ' + l.code
from [Floor] f
cross join [Language] l
where f.something not in ( 'F1.1', 'F1.2', 'F2.1')
and l.code in ('en-us')


declare @defaultLanguageId bigint
select @defaultLanguageId = id from [Language] where code = 'en-us' --default language is US English

select b.Id
, b.something
, bn.name
, isnull(bfn.name, bfnDefault.name)
, bl.code BuildingLanguage
from [Building] b
inner join [BuildingName] bn
    on bn.BuildingId = b.Id
inner join [Language] bl
    on bl.Id = bn.LanguageId
inner join [Floor] bf
    on bf.BuildingId = b.Id
left outer join [FloorName] bfn
    on bfn.FloorId = bf.Id
    and bfn.LanguageId = bl.Id
left outer join [Language] bfl
    on bfl.Id = bfn.LanguageId
left outer join [FloorName] bfnDefault
    on bfnDefault.FloorId = bf.Id
    and bfnDefault.LanguageId = @defaultLanguageId

EDIT

This version defaults any language:

select b.Id
, b.something
, bn.name
, isnull(bfn.name, (select top 1 name from [FloorName] x where x.FloorId=bf.Id))
, bl.code BuildingLanguage
from [Building] b
inner join [BuildingName] bn
    on bn.BuildingId = b.Id
inner join [Language] bl
    on bl.Id = bn.LanguageId
inner join [Floor] bf
    on bf.BuildingId = b.Id
left outer join [FloorName] bfn
    on bfn.FloorId = bf.Id
    and bfn.LanguageId = bl.Id
left outer join [Language] bfl
    on bfl.Id = bfn.LanguageId