Svendson, Stephen
Table
Chair
Pettersen, Kari
解释:
LEFT JOIN返回”first_table”中所有的行尽管在” second_table”中没有相匹配的数据。
RIGHT JOIN的语法:
SELECT field1, field2, field3
FROM first_table
RIGHT JOIN second_table
ON first_table.keyfield = second_table.foreign_keyfield
用”Employees”表去右外联结”Orders”表去找出相关数据:
SELECT Employees.Name, Orders.Product
FROM Employees
RIGHT JOIN Orders
ON Employees.ID = Orders.ID
返回结果:
Name
Product
Hansen, Ola
Printer
RIGHT JOIN
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