來自微信公眾號(hào)“Java編程精選”

下圖展示了LEFT JOIN、LEFT JOIN、INNER JOIN、OUTER JOIN相關(guān)的七種用法

1.INNER JOIN 內(nèi)連接

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SELECT <select_list> FROM table_A A INNER JOIN table_B B ON A.key=B.key

2. LEFT JOIN 左連接

SELECT <select_list> FROM table_A A LEFT JOIN table_B B ON A.key=B.key

3.RIGTH JOIN 右連接

SELECT <select_list> FROM table_A A RIGHT JOIN table_B B ON A.key=B.key

4. OUTER JOIN 外連接

SELECT <select_list> FROM table_A A FULL OUTER JOIN table_B B ON A.key=B.key

5.LEFT JOIN EXCLUDING INNER JOIN 左連接-內(nèi)連接

SELECT <slelct_list> FROM table_A A LEFT JOIN table_B B ON A.key=B.key WHERE B.key IS NULL

6.RIGHT JOIN EXCLUDING INNER JOIN 右連接-內(nèi)連接

SELECT <select_list> FROM table_A A RIGHT JOIN table_B B ON A.key=B.key WHERE A.key IS NULL

7.OUTER JOIN EXCLUDING INNER JOIN 外連接-內(nèi)連接

SELECT <select_list> FROM table_A A FULL OUTER JOIN table_B B ON A.key=B.key WHERE A.key IS NULL OR B.key IS NULL

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