下圖展現了 LEFT JOIN、RIGHT JOIN、INNER JOIN、OUTER JOIN 相關的 7 種用法。3d

具體分解以下:blog
一、INNER JOIN(內鏈接)get

- SELECT FROM Table_A AINNER JOIN Table_B BON A.Key = B.Key
二、LEFT JOIN(左鏈接)im

- SELECT FROM Table_A ALEFT JOIN Table_B BON A.Key = B.Key
三、RIGHT JOIN(右鏈接)d3

- SELECT FROM Table_A ARIGHT JOIN Table_B BON A.Key = B.Key
四、OUTER JOIN(外鏈接)db

- SELECT FROM Table_A AFULL OUTER JOIN Table_B BON A.Key = B.Key
五、LEFT JOIN EXCLUDING INNER JOIN(左鏈接-內鏈接)img

- SELECT FROM Table_A ALEFT JOIN Table_B BON A.Key = B.KeyWHERE B.Key IS NULL
6.RIGHT JOIN EXCLUDING INNER JOIN(右鏈接-內鏈接)co

- SELECT FROM Table_A ARIGHT JOIN Table_B BON A.Key = B.KeyWHERE A.Key IS NULL
七、OUTER JOIN EXCLUDING INNER JOIN(外鏈接-內鏈接)360

- SELECT FROM Table_A AFULL OUTER JOIN Table_B BON A.Key = B.KeyWHERE A.Key IS NULL OR B.Key IS NULL