学生管理部分

#include<myhead.h>
int main(int argc, char *argv[])
{
	sqlite3* ppDb=NULL;
	if(sqlite3_open("./mydb.db",&ppDb)!=SQLITE_OK)
	{
		printf("sqlite3_open error:%s\n",sqlite3_errmsg(ppDb));
		return -1;
	}
 
	//创建数据表
	char arg[128]="create table if not exists stu(num int primary key,name char,score double)";
	char *errmsg=NULL;
	if(sqlite3_exec(ppDb,arg,NULL,NULL,&errmsg)!=SQLITE_OK)
	{
		printf("%s\n",errmsg);
		return -1;
	}
	int num;
	char name;
	double score;
	while(1)
	{
		printf("***************学生管理系统************\n");
		printf("*************1.添加学生信息************\n");
		printf("*************2.删除学生信息************\n");
		printf("*************3.修改学生信息************\n");
		int a;
		scanf("%d",&a);
		getchar();
		switch(a){
		case 1:
			{
				printf("请输入学号:");
				scanf("%d",&num);
				getchar();
				printf("请输入姓名:");
				scanf("%s",&name);
				getchar();
				printf("请输入成绩:");
				scanf("%lf",&score);
				getchar();
				arg[128]=("insert into stu values (%d,%s,%lf);",num,name,score);
				if(sqlite3_exec(ppDb,arg,NULL,NULL,&errmsg)!=SQLITE_OK)
				{
					printf("%s\n",errmsg);
					return -1;
				}
				printf("学生信息录入成功\n");
			}
			break;
		case 2:
			{
				printf("请输入学号:");
				scanf("%d",&num);
				getchar();
				arg[128]=("delete from stu where num=%d;",num);
				if(sqlite3_exec(ppDb,arg,NULL,NULL,&errmsg)!=SQLITE_OK)
				{
					printf("%s\n",errmsg);
					return -1;
				}
				printf("学生信息删除成功\n");
			}
			break;
		case 3:
			{
				printf("请输入学号:");
				scanf("%d",&num);
				getchar();
				printf("请输入成绩:");
				scanf("%lf",&score);
				getchar();
				arg[128]=("update stu set score=%lf where num=%d;",score,num);
				if(sqlite3_exec(ppDb,arg,NULL,NULL,&errmsg)!=SQLITE_OK)
				{
					printf("%s\n",errmsg);
					return -1;
				}
				printf("学生信息修改成功\n");
				
			}
			break;
		}
	}
	sqlite3_close(ppDb);
	
	return 0;
}