Question

salesperson:(sid, name, age, salary)
customer :(cid, cname, city)
order:(oid, order_date, cid, sid, amount)

“查找具有两个或更多订单的销售人员姓名”的SQL查询

Answer 1

SELECT s.name, count(o.oid) FROM salesperson s, order o
WHERE s.sid=o.sid
GROUP BY s.name
HAVING count(o.oid)>=2

我们在这里使用的是"Inner Join"，其中只提取了对应的行（where s.sid=o.sid）。

Answer 2

SELECT s.name, count(*) order_count
FROM salesperson AS s, order AS o
WHERE s.sid = o.sid
GROUP BY s.name 
HAVING COUNT(*) > 1

这将返回名称以及与每个销售人员相关的订单数量

Answer 3

测试良好

SELECT sp.NAME 
FROM   salesperson AS sp 
       INNER JOIN order AS ord 
               ON salesperson.sid = ord.sid 
GROUP  BY sp.sid 
HAVING Count(ord.oid) >= 2

以下db的SQL查询

3 个答案: