# 求和练习 Joe 想要得到 orders 表 ```sql create table orders ( id int primary key auto_increment, item_id int, amount int, unit_price decimal(12, 4), total decimal(12, 4), description varchar(2000), ts timestamp default now(), deal bool default false ); ``` 中所有单价(unit_price)超过 1000 的订单中,已成交(deal 为 true)的总值(total),这个查询应该是:
点击进入[MySQL实战练习环境](https://mydev.csdn.net/product/pod/new?image=cimg-centos7-skilltreemysql&connect=auto&create=auto&utm_source=skill){target="_blank"}。 * `show databases;` 列出所有数据库 * `show tables;` 列出所有表 ## 答案 ```sql select sum(total) from orders where deal and unit_price > 1000; ``` ## 选项 ### A ```sql select sum(total) from orders having deal and unit_price > 1000; ``` ### B ```sql select sum(total) from orders group by deal having unit_price > 1000; ``` ### C ```sql select sum(total) from orders order by deal and unit_price > 1000; ```