SQl查询检索数据

Question

我无法弄清楚如何从我的表中获取所需的数据。这是我写的显示错误说子查询返回多行查询..

SELECT name 
FROM `business` 
WHERE id = (
SELECT business_id 
FROM bill 
WHERE id = (
SELECT bill_id 
FROM bill_schedule 
WHERE show_bill = 1) 

这里bill_schedule子查询返回多行，其中show_bill是一个布尔列。所有我想在这里是从它的show_bill设置为1

Answer 1

SELECT `name` 
FROM `business` 
WHERE id in (
SELECT business_id 
FROM bill 
WHERE id in (
SELECT bill_id 
FROM bill_schedule 
WHERE show_bill = 1) 

Answer 2

由于子查询返回多行的业务显示“名称”，则不能使用相等运算符

刚在您的where子句中将=更改为IN：

SELECT name 
FROM `business` 
WHERE id IN (
SELECT business_id 
FROM bill 
WHERE id IN (
SELECT bill_id 
FROM bill_schedule 
WHERE show_bill = 1)