1.实验目的
学会使用高级语言访问MySQL数据库,并进行查询。
2.实验环境
Windows XP操作系统、MySQL关系数据库管理系统、MinGW编译器或Microsoft Visual C++编译器。
本次实验主要利用C语言访问MySQL数据库,也可以使用JAVA,PHP等其他语言。
3.实验内容
3.1实验任务
在上次上机实验课建立的COMPANY数据库上,用C语言编写程序,完成如下查询,程序的命令行参数为:
company_query –q -p [Parameters]
其中,Number代表待执行查询的序号,Parameters为第Number号查询需要的参数列表。
待执行的9个查询为如下:
1:参加了项目编号为%PNO%的项目的员工号,其中%PNO%为C语言编写的程序的输入参数;
SELECT ESSN
from employee natural join works_on
where pno='P1'
2:参加了项目名为%PNAME%的员工名字,其中%PNAME%为C语言编写的程序的输入参数;
SELECT ename
from employee ,works_on, project
where employee.ESSN=works_on.ESSN and works_on.PNO=project.pno and PNAME ='SQL Project'
3:在%DNAME%工作的所有工作人员的名字和地址,其中%DNAME%为C语言编写的程序的输入参数;
SELECT ename,ADDRESS
from employee NATURAL join department
where DNAME='研发部'
4:在%DNAME%工作且工资低于%SALARY%元的员工名字和地址,其中%DNAME%和%SALARY%为C语言编写的程序的输入参数;
SELECT ename,ADDRESS
from employee NATURAL join department
where DNAME='研发部' and SALARY<3000
5:没有参加项目编号为%PNO%的项目的员工姓名,其中%PNO%为C语言编写的程序的输入参数;
SELECT DISTINCT ename
from employee
where ename not in (
SELECT DISTINCt ename
from employee NATURAL join works_on
where pno="P1"
)
6:由%ENAME%领导的工作人员的姓名和所在部门的名字,,其中%ENAME%为C语言编写的程序的输入参数;
SELECT ename,dname
from employee natural join department
where SUPERSSN=(
select eSSN
from employee
where ename='张红'
)
7:至少参加了项目编号为%PNO1%和%PNO2%的项目的员工号,其中%PNO1%和%PNO2%为C语言编写的程序的输入参数;
SELECT essn
from employee natural join works_on
where pno='P1' and essn in (
select essn
from employee natural join works_on
where pno ='P2'
)
8:员工平均工资低于%SALARY%元的部门名称,其中%SALARY%为C语言编写的程序的输入参数;
SELECT dNAME
from employee natural join department
GROUP BY dno
HAVING avg(SALARY)<3400
9:至少参与了%N%个项目且工作总时间不超过%HOURS%小时的员工名字,其中%N%和%SALARY%为C语言编写的程序的输入参数;
SELECT eNAME
from employee natural join works_on
GROUP BY eNAME
HAVING count(pno)> 2 and sum(HOURS)>=8
注意:
(1)在上课之前需准备上节实验所需要用到的COMPANY数据库.
(2)每人抽查三个查询,根据抽查情况给分
$pmt1 and sum(HOURS)>=$pmt2"; $res .= "eNAME"; break; } echo $sql . ""; $servername = "localhost"; $username = "root"; $password = "root"; $dbname = "company"; // 创建连接 $conn = new mysqli ( $servername, $username, $password, $dbname ); // 检测连接 if ($conn->connect_error) { die ( "Connection failed: " . $conn->connect_error ); } // $sql = "SELECT * FROM employee"; $result = $conn->query ( $sql ); $num = mysqli_num_fields ( $result ); if ($result->num_rows > 0) { // 输出每行数据 while ( $row = $result->fetch_row () ) { for($i = 0; $i < $num; $i ++) { $res .= $row [$i] . " "; } $res .= ""; } } else { echo "0 results"; } echo $res; $conn->close (); ?>