randrecord.c

sql数据库的实现

#include "mydb.h"
char *major[]={"电子","土木","能源","电信","建规","机械","计算机系","软件","经管","数学系","物理系","化学系","道桥","中文系"};
char *subname[]={"马哲","电路","数电","模电","固电","量子","复变","物理","微积分","线代",\
		"体育","英语","语文","C语言","近代史","信号","思修","概率论","单片机","数据库",\
		"工程制图","电工实习","军事理论","毛概"};
//以上字符串数组都是为了随机产生数据库用到

//本函数将用于产生长为wordsize，类型为type的字符串
//并将其放于buf中
bool makeword(char*buf,int wordsize,int type)
{
	int i=0;
	if(!buf)return FALSE;
	memset(buf,0,BUFSIZE);
	for(;i<wordsize&&i<20;i++)
	if(type==ALPHAWORD)buf[i]=97+myrand(0,25);
	else if(type==NUMBERWORD)buf[i]=48+myrand(0,9);
	else return FALSE;
	return TRUE;
}




//本函数用于随机将专业与年号班级相搭配
//组成类似"电子0603"的字符串放于buf中
bool makemajor(char *buf)
{
	int majorcount=sizeof(major)/sizeof(char*);	
	int randmajor=myrand(1,10000)%majorcount,randyear=1978+myrand(1,10000)%31;
	randyear%=100;
	int randclass=myrand(1,10000)%20+1;
	memset(buf,0,BUFSIZE);
	char temp[10]={0};
	itoa(randyear,temp,10);
	if(randyear<10)
	{
		temp[1]=*temp;
		*temp=0x30;
	}
	sprintf(buf,"%s%s",major[randmajor],temp);
	memset(temp,0,10);
	itoa(randclass,temp,10);
	if(randclass<10)
	{
		temp[1]=*temp;
		*temp=0x30;
	}
	sprintf(buf,"%s%s",buf,temp);
	return TRUE;
}


//随机产生学生信息的总控制函数
bool makestu(long stucount)
{
	long i=0;
	srand(time(0));char buf[20];
	pmystu newstu=NEW(mystu);
	printf("\n系统正在产生学生信息......");
	for(;i<stucount;i++)
	{
		memset(newstu,0,MYSTUSIZE);
		newstu->stu_sex=myrand(1,10000)%2;
		if(!makeword(buf,myrand(3,10),ALPHAWORD))return FALSE;
		memcpy(newstu->stu_name,buf,BUFSIZE);
		printf("%s",buf);
		head(BUFSIZE-strlen(buf)+8);
		memset(buf,0,BUFSIZE);
		itoa((i+1)*100/stucount,buf,10);
		strcat(buf,"%");
		printf("%s",buf);
		back(BUFSIZE+strlen(buf)+8);
		if(!makeword(buf,12,NUMBERWORD))return FALSE;
		if(search(buf,SEARCH_SCHID)){i--;continue;}
		memcpy(newstu->stu_schid,buf,BUFSIZE);
		makemajor(buf);
		memcpy(newstu->stu_major,buf,BUFSIZE);
		addstu(newstu);
	}
	head(50);back(50);
	printf("学生信息产生成功!\n");
	return TRUE;
}



//随机产生学科信息的函数
//学分和开课学期具有随机性
bool makesub()
{
	printf("\n系统正在产生学科信息......");
	psubinfo newsub=NEW(subinfo);
	int i;
	int randsubcount=sizeof(subname)/sizeof(char*);
	for(i=0;i<randsubcount;i++)
	{
		memset(newsub,0,SUBINFOSIZE);
		newsub->sub_term=myrand(1,8);
		newsub->sub_rate=myrand(2,12)*0.5;
		strcpy(newsub->sub_name,subname[i]);
		if(search(newsub->sub_name,SEARCH_SUB))
		{i--;continue;}
		addsub(newsub);
	}
	printf("学科信息产生成功!\n");
	return TRUE;
}



//每个学生和每门学科的分数都将随机产生并写入数据库
bool makemark()
{
	if(!myfileinfo)
	{
		myfileinfo=NEW(fileinfo);
		fcntl(0,READ,myfileinfo,FILEINFOSIZE);
	}
	printf("\n系统正在产生分数信息......");
	psubmark newmark=NEW(submark);
	long seek=DATASEEK;
	newmark->flag=1;int i,j;
	for(i=0;i<myfileinfo->stucount;i++,seek+=DATATRANS)
	for(j=0;j<myfileinfo->subcount;j++)
	{
		newmark->sub_id=j+1;
		newmark->sub_mark=50+myrand(0,100)*0.5;
		editmark(newmark,seek);
	}
	printf("学生分数信息产生成功!\n");
	return TRUE;
}




//本函数随机产生范围x~y的随机数
//包括超大数
long myrand(long x,long y)  
{   
	int a=rand();  
	int b=rand();
	int c=rand();
	long g=a*b+c;
	g=x+g%(y-x+1);
	return g;
}   




//随机建立数据库的总控制函数
bool MakeDataBase()
{
	long stucount=0;
	printf("\n\n请输入想要产生的学生记录数:");
	scanf("%ld",&stucount);
	printf("\n系统将为您产生%ld个学生的相关记录.....\n",stucount);
	printf("\n系统正在自动为您建立数据库，请稍后......\n");
	if(!makestu(stucount))SETERR("\n\n数据库建立失败!\n\n");
	if(!makesub())SETERR("\n\n数据库建立失败!\n\n");
	if(!makemark())SETERR("\n\n数据库建立失败!\n\n");
	printf("\n数据库建立成功!系统为您建立了");
	printf("%ld 个学生和%d门科目及所有成绩!\n\n",stucount,RANDSUBCOUNT);
	printf("\n\n请按任意键继续.....\n\n");
	getch();
	return TRUE;
}


void back(int i)
{
	int j=0;
	for(;j<i;j++)
		printf("\b");
}

void head(int i)
{
	int j=0;
	for(;j<i;j++)
		printf(" ");
}