MS SQL Stored procedure to get the value - sql

Question

I have 3 tables
Staff table:
EmpId CandidateId
------------------------
1 2
Candidate table:
CandidateId Firstname Last name CountryId PassportCountry
--------------------------------------------------------------------
1 Mark Antony 2 3
2 Joy terry 1 3
Country:
CountryId Name
---------------------------
1 USA
2 UK
3 Australia
User will pass the EmpId in the querystring I need to show the candidate details according to the empId. I have only one country table and using that table for country, passportport country. So I need to get the country name when I get the candidate value.
How to write the stored procedure to get the candidate details. Im not good in sql. Can you guys help me on this. Thanks in advance.
Hi I tried the below script to get the country name and passport country name. I can get the country name, but not the passport country.
SELECT
FirstName,
LastName,
PassportCountry,
Country.CountryName as Country
from Candidate
inner join Country
on country.CountryId=candidate.country
where CandidateId=#CandidateId;

Answer 1

This should get you going in the right direction.
Basically, since you're referencing the Country table twice, you need to join it twice.
declare #staff table (EmpId int, CandidateId int)
insert into #staff values (1, 2 )
declare #Candidate table (CandidateId int, Firstname nvarchar(50), Lastname nvarchar(50), CountryId int, PassportCountry int)
insert into #Candidate
values (1, 'Mark', 'Antony', 2, 3),
(2, 'Joy', 'Terry', 1, 3)
declare #Country table (CountryId int, Name nvarchar(50))
insert into #Country
values (1, 'USA'),
(2, 'UK'),
(3, 'Australia')
declare #empID int
set #empID = 1
SELECT
FirstName,
LastName,
t2.Name as PersonCountry,
t3.Name as PassportCountry
from #staff s
inner join #Candidate t1 on s.CandidateId = t1.CandidateId
inner join #Country t2 on t1.CountryId=t2.CountryId
inner join #Country t3 on t1.PassportCountry=t3.CountryId
where s.EmpId=#empID;