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mysql数据库考试题库

一、不定项选择题(共40题,每小题2.5分,总分100分)1. 数据库管理系统的发展历经了如下那些模型阶段( ACDE ) A. 层次模型 B. 结构模型 C. 关系模型 D. 网状模型 E.对象模型2. 关系型数据库的核心单元是( B ) A. 对象 B. 表 C. 行 D. 列

select `stu_id`,avg(`grade`),sum(`grade` =2'avg(`grade`):求平均值sum(`grade` =2:判断统计的个数大于2

1 select b.dname,count(*) from emp a,dept b where a.deptno=b.deptno group by b.dname having count(*)>32 select grade from salarygrade where (select avg(sal) avgsal from emp where deptno=(select deptno from dept where dname='

foreach($abc as $k => $t) { $r[$t[0]]++; } foreach($abc as $s => $v){ $rr[$v[1]]=$r[$v[0]]; if($v[0]!=$abc[1][$v[0]]){ $rr[$v[1]]=$r[$v[0]]; } }

1.SELECT DISTINCT sc_number,sc_name FROM dbo.score WHERE sc_sex='0' AND sc_number LIKE '98%'2.SELECT s.sc_name,c.co_name,s.sc_score FROM dbo.score s JOIN dbo.course c ON s.sc_courseid=c.co_id WHERE sc_score<603.

1.DB22.Oracle3.sql server4.mysql5.Access

select max(score) from grade select sum(score) from grade group by name limit(2,4) select sum(score) from grade group by name where sum(score) < 150 select name,avg(sum(score)) from grade group by name where avg(sum(score)) > 60 and

buttonRemove.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { IStructuredSelection selection = (IStructuredSelection)listViewer.getSelection(); Language language = (Language)selection.

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