select cust_name,order_num from Customers left join Orders using(cust_id) order by cust_name 

select cust_name,order_num from Customers inner join Orders using(cust_id) order by cust_name 

with t1 as ( select order_num     from OrderItems     where prod_id="BR01" ) select cust_id,order_date from t1 inner join Orders on t1.order_num=Orders.order_num order by order_date

select cust_name,t3.order_num ,sum(quantity*item_price) as OrderTotal from Customers t1  inner join  Orders t2 on t1.cust_id=t2.cust_id inner join OrderItems t3 on t2.order_num=t3.order_num group by cust_n...

select     prod_name,sum(quantity) as     quant_sold from Products join OrderItems on Products.prod_id=OrderItems.prod_id group by prod_name

select cust_id,sum(sum_ordered)as total_ordered from( select order_num,item_price,sum(quantity)*item_price as sum_ordered from OrderItems group by order_num,item_price )t1 join Orders on t1.order_num=Orders.order_num group by cust_id order by total_ordered desc;

select cust_id,order_date from Orders join OrderItems on Orders.order_num=OrderItems.order_num where prod_id='BR01' order by order_date

SELECT order_num, COUNT(*) AS items  FROM OrderItems  GROUP BY order_num HAVING COUNT(*) >= 3 ORDER BY items, order_num

select order_num from( select order_num,sum(quantity) sum_q from OrderItems group by order_num )t1 where sum_q>100 order by order_num

select cust_id, cust_name, #upper(concat(left(cust_name,2),left(cust_city,3))) as user_login upper(concat(substring(cust_name,1,2),substring(cust_city,1,3))) as user_login from Customers  拼接concat 字符串相关函数 upper转大写，lower小写 substring 子字符串 left/right返回从左、右开始对应个数字符串

select prod_name,prod_desc from Products where prod_desc  like "%toy%" and prod_desc  like "%carrots%"

名字终于变黄色了

求大数据大佬

select c.course_id,course_name,round(sum(if_sign)*100/count(if_vw),2) from course_tb c join behavior_tb b where c.course_id=b.course_id group by c.course_id,course_name