PostgreSQL-错误：列不存在SQL状态：42703

Question

我正在尝试进行队列分析，并根据承租人的第一个租赁年份（=承租人第一次租赁的年份）比较平均租金。基本上，我在问一个问题：我们是否保留第一年是2013年的房客而不是第一年是2015年的房客？

这是我的代码：

SELECT renter_id, 
       Min(Date_part('year', created_at)) AS first_rental_year, 
       ( Count(trip_finish) )             AS number_of_trips 
FROM   bookings 
WHERE  state IN ( 'approved', 'aboard', 'ashore', 'concluded', 'disputed' ) 
  AND  first_rental_year = 2013 
GROUP  BY 1 
ORDER  BY 1; 

我收到的错误消息是：

ERROR:  column "first_rental_year" does not exist
LINE 6: ... 'aboard', 'ashore', 'concluded', 'disputed') AND first_rent...
                                                             ^

********** Error **********

ERROR: column "first_rental_year" does not exist
SQL state: 42703
Character: 208

任何帮助深表感谢。

Answer 1

SELECT renter_id,
       Count(trip_finish) AS number_of_trips 
FROM (
        SELECT renter_id, 
               trip_finish,
               Min(Date_part('year', created_at)) AS first_rental_year
        FROM   bookings 
        WHERE  state IN ( 'approved', 'aboard', 'ashore', 'concluded', 'disputed' ) 
     ) T
WHERE first_rental_year = 2013  
GROUP  BY renter_id
ORDER  BY renter_id ;