[LeetCode] 584. Find Customer Referee

Given a table customer holding customers information and the referee.

+------+------+-----------+

| id   | name | referee_id|

+------+------+-----------+

|    1 | Will |      NULL |

|    2 | Jane |      NULL |

|    3 | Alex |         2 |

|    4 | Bill |      NULL |

|    5 | Zack |         1 |

|    6 | Mark |         2 |

+------+------+-----------+

Write a query to return the list of customers NOT referred by the person with id '2'.

For the sample data above, the result is:

+------+

| name |

+------+

| Will |

| Jane |

| Bill |

| Zack |

+------+

note: 要用 is Null 和 != .

Code

SELECT name FROM customer WHERE referee_id != 2 OR referee_id IS NULL

巴特西

[LeetCode] 584. Find Customer Referee_Easy tag: SQL

最新文章

热门文章