Where Complex Results and NULLS - SQL C# - sql

Question

I have a query in the database with a textbox that brings me from another field if there is a record but I want it to bring me a null when it does not exist in the base
SELECT [restaurantes]
,[ubicacion]
FROM [col].[dbo].[bog]
where restaurantes in ('colombia','bogota')
and result is this :
restaurantes - ubicacion
colombia - norte_espa
and not get bogota because not have register in database i need restaurant and ubicacion i need show null
result :
restaurantes - ubicacion
colombia - norte_espa
bogota - Null or Not exists that register
its possible ?

Answer 1

You can use a VALUES clause as the driving row, along with a LEFT JOIN
SELECT v.[restaurantes]
,b.[ubicacion]
FROM (VALUES
('colombia'),
('bogota')
) v(restaurantes)
LEFT JOIN [col].[dbo].[bog] b ON b.restaurantes = v.restaurantes;
For very old versions of SQL Server which do not support VALUES you can use UNION ALL in a subquery
SELECT v.[restaurantes]
,b.[ubicacion]
FROM (
SELECT 'colombia' AS restaurantes
UNION ALL
SELECT 'bogota'
) v
LEFT JOIN [col].[dbo].[bog] b ON b.restaurantes = v.restaurantes;

Answer 2

Perhaps string_split() in concert with a Left Join
Example
Select restaurantes = a.value
,B.[ubicacion]
From string_split('colombia,bogota',',') A
Left Join [col].[dbo].[bog] B
on A.value = B.restaurantes
Update Lower Version of SQL Server
Declare #List varchar(max) = 'colombia,bogota'
Select restaurantes = a.RetVal
,B.[ubicacion]
From (
Select RetSeq = row_number() over (order by 1/0)
,RetVal = ltrim(rtrim(B.i.value('(./text())[1]', 'varchar(max)')))
From (Select x = Cast('<x>' + replace((Select replace(#List,',','§§Split§§') as [*] For XML Path('')),'§§Split§§','</x><x>')+'</x>' as xml).query('.')) as A
Cross Apply x.nodes('x') AS B(i)
) A
Left Join [col].[dbo].[bog] B
on A.RetVal = B.restaurantes