有三个表 Employee (EID,NAME)
Course(CID,NAME,STARTTIME,ENDTIME)
Employee_Course(EID,CID);
员工表,课程表,还有关系表,记录的是员工和课程的主键.
现在要查询出Employee.EID,Employee.NAME,Course.NAME,Course.STARTTIME. 条件是给出课程的名称.
Course(CID,NAME,STARTTIME,ENDTIME)
Employee_Course(EID,CID);
员工表,课程表,还有关系表,记录的是员工和课程的主键.
现在要查询出Employee.EID,Employee.NAME,Course.NAME,Course.STARTTIME. 条件是给出课程的名称.
from Employee e,Course c,Employee_Course ec
where e.eid=ec.eid and c.cid=ec.cid
select a.EID,a.NAME,c.NAME,c.STARTTIME from Employee a left join Employee_Course b on a.eid=b,eid left join Course c on b.cid=c.cid where c.name=''
from Employee e,Course c,Employee_Course ec
where e.eid=ec.eid and c.cid=ec.cid and c.name='给出的课程名称'
from Employee as e inner join Employee_Course as ec on e.EID=ec.EID
inner join Course as c on ec.CID=c.CID
where c.NAME='课程的名称'
from Employee e
left join Employee_Course ec on ec.EID = e.EID
left join Course c on c.CID = ec.CID
where c.NAME = 给定课程的名称