摘要： Student类class Student{ String name; String pwd; public Student(){} public Student(String name, String pwd){ this.name = name; this.pwd = pwd; } publ... 阅读全文

摘要： http://zhidao.baidu.com/question/101592007.html?fr=qrl&index=0&qbl=topic_question_0&word=window%20%CA%F3%B1%EA%D3%D2%BC%FC%B2%CB%B5%A5开始 运行 regedit展开 ... 阅读全文

摘要： select *from emp;select deptno from emp;select distinct deptno from emp;--过滤deptno 重复的数据distinct 对null也会过滤select distinct comm, deptno from emp;--过滤co... 阅读全文

摘要： select *from emp;//查询emp表内容select ename, job from emp;//从emp表中查询ename和job列select ename, sal from emp;//在表emp中查询ename和sal列select ename, sal*12 from emp... 阅读全文