select et.employeeid,et.territoryid,e.firstname,e.lastname from employeeterritories as et,employees as e
where et.territoryid between '20000' and '29999'
为什么结果只选中employee表里面相关的部分而不是全部?我并没有对employee表进行限定啊?这是因为表的关系的缘故?