php - MYSQL - 错误代码 :- 1241 "Operand should contain 1 column(s) "

Question

我正在做一个项目。
我有以下查询

select sid, reading, (
    select customer_id as cid, sub_location_id as location_id
    from customer_information  where sub_location_id = 1)
    from customer_consumption 
where customer_consumption.customer_id = customer_information.customer_id 
and month(bill_date) = month(now())

帮助解决这个问题

Answer 1

您似乎想要显式加入:

select cc.sid, cc.reading, 
       ci.customer_id as cid, ci.sub_location_id as location_id
from customer_consumption cc join
     customer_information ci
     on cc.customer_id = ci.customer_id 
where month(bill_date) = month(now()) and ci.sub_location_id = 1;

你原来的语法是非常不正统的。您似乎需要进一步了解如何使用 SQL。