1. JOIN : 두 테이블의 정보를 결합하여 하나의 결과 집합인 "가상" 테이블을 만드는 것
2. INNER JOIN
1) 구문
SELECT <선택 목록>
FROM <첫 번째 테이블>
<조인 유형> <두번째 테이블>
[ON <조인 조건>]
2) 간단한 JOIN
SELECT p.ProductID, s.SupplierID, p.ProductName, s.CompanyName
FROM Products p
INNER JOIN Suppliers s
ON p.SupplierID = s.SupplierID
WHERE p.ProductID < 4
3) 복잡한 JOIN
SELECT au_lname + ', ' + au_fname AS "Author", t.title
FROM authors a
JOIN titleauthor ta
ON a.au_id = ta.au_id
JOIN titles t
ON t.title_id = ta.title_id
3. OUTER JOIN
1) 구문
SELECT <SELECT 목록>
FROM <왼쪽 테이블>
<LEFT|RIGHT> [OUTER] JOIN <오른쪽 테이블>
ON <조인조건>
2) LEFT OUTER JOIN
SELECT discounttype, discount, s.stor_name
FROM discounts d
LEFT OUTER JOIN stores s
ON d.stor_id = s.stor_id
Initial Customer 10.50 NULL
Volume Discount 6.70 NULL
Customer Discount 5.00 Bookbeat
3) RIGHT OUTER JOIN
SELECT discounttype, discount, s.stor_name
FROM discounts d
RIGHT OUTER JOIN stores s
ON d.stor_id = s.stor_id
※ 출처: Beginning SQL Server 2005 Programming