ВВЕРХ

SQL RIGHT JOIN

SQL RIGHT JOIN Описание

Ключевое слово RIGHT JOIN возвращает все записи из правой таблицы (table2) и соответствующие записи из левой таблицы (table1).

Результатом будет 0 записей слева, если нет соответствия.


RIGHT JOIN Синтаксис

SELECT column_name(s)
FROM table1
RIGHT JOIN table2
ON table1.column_name = table2.column_name
В некоторых базах данных RIGHT JOIN вызывается как RIGHT OUTER JOIN.

SQL INNER JOIN

Демонстрационная база данных

В этом справочнике мы будем использовать известный пример базы данных "Northwind".

Ниже приведена выборка из таблицы "Orders" ("Заказ"):

ProductIDOrderIDCustomerIDEmployeeIDOrderDateShipperID
1102489051996-07-043
2102498161996-07-051
3102503441996-07-082
4102518431996-07-081
5102527641996-07-092

И выборка из таблицы "Employees" ("Работники"):

EmployeeIDLastNameFirstNameBirthDatePhotoNotes
1Davolio Nancy 12/8/1968 EmpID1.pic Education includes a BA in psychology from Colorado State University. She also completed (The Art of the Cold Call). Nancy is a member of 'Toastmasters International'.
2Fuller Andrew 2/19/1952 EmpID2.pic Andrew received his BTS commercial and a Ph.D. in international marketing from the University of Dallas. He is fluent in French and Italian and reads German. He joined the company as a sales representative, was promoted to sales manager and was then named vice president of sales. Andrew is a member of the Sales Management Roundtable, the Seattle Chamber of Commerce, and the Pacific Rim Importers Association.
3Leverling Janet 8/30/1963 EmpID3.pic Janet has a BS degree in chemistry from Boston College). She has also completed a certificate program in food retailing management. Janet was hired as a sales associate and was promoted to sales representative.
4Peacock Margaret 9/19/1958 EmpID4.pic Margaret holds a BA in English literature from Concordia College and an MA from the American Institute of Culinary Arts. She was temporarily assigned to the London office before returning to her permanent post in Seattle.
5Buchanan Steven 3/4/1955 EmpID5.pic Steven Buchanan graduated from St. Andrews University, Scotland, with a BSC degree. Upon joining the company as a sales representative, he spent 6 months in an orientation program at the Seattle office and then returned to his permanent post in London, where he was promoted to sales manager. Mr. Buchanan has completed the courses 'Successful Telemarketing' and 'International Sales Management'. He is fluent in French.

SQL RIGHT JOIN Пример

Следующая SQL-инструкция вернет всех сотрудников и любые заказы, которые они могли разместить:

Run SQLSELECT Orders.OrderID, Employees.LastName, Employees.FirstName 
FROM Orders 
RIGHT JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID 
ORDER BY Orders.OrderID
Ключевое слово RIGHT JOIN возвращает все записи из правой таблицы (Сотрудники), даже если нет совпадений в левой таблице (Заказ).