我開始簡單:幻影「名字」專欄?
hoops=# select * from core_school limit 3;
id | school_name | nickname
----+------------------+----------
1 | Marshall |
2 | Ohio |
3 | Houston |
(10 rows)
讓我們介紹一個故意的錯誤:
hoops=# select name from core_school;
ERROR: column "name" does not exist
LINE 1: select name from core_school;
但是,爲什麼這項工作? (出乎意料的結果!):
hoops=# select core_school.name from core_school limit 3;
name
-----------------
(1,Marshall,"")
(2,Ohio,"")
(3,Houston,"")
(3 rows)
「name」列在第三個查詢中來自何處?