思维导图

数据库编程实现学生管理系统

#include <header.h>
#define ID 1
#define NAME 2
#define AGE 3
#define SCORE 4
int do_add(sqlite3 *ppdb)
{
	int add_numb;
	char add_name[20];
	int add_age;
	double add_score;
	printf("enter student id:");
	scanf("%d",&add_numb);
	printf("enter student name:");
	scanf("%s",add_name);
	printf("enter student age:");
	scanf("%d",&add_age);
	printf("enter student score:");
	scanf("%lf",&add_score);
	getchar();
	char sql[128]="";
	snprintf(sql,sizeof(sql),"insert into stu values(%d,\"%s\",%d,%.2lf);",add_numb,add_name,add_age,add_score);
	char *errmsg=NULL;
	if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
	{
		printf("stu create fail:%s\n",errmsg);
		sqlite3_free(errmsg);
		return 1;
	}
	printf("table stu create success\n");
	return 0;
}
int callback(void* arg,int cols,char** col_text,char** col_name)
{
	if(*(int *)arg==0)
	{
		for(int i=0;i<cols;i++)
		{
			printf("%s\t",col_name[i]);
		}
		printf("\n");
		*(int *)arg=1;
	}
	for(int i=0;i<cols;i++)
	{
		printf("%s\t",col_text[i]);
	}
	printf("\n");
	return 0;
}
int do_select(sqlite3 *ppdb)
{
	int flag=0;
	char sql[128]="select * from stu;";
	char *errmsg=NULL;
	if(sqlite3_exec(ppdb,sql,callback,&flag,&errmsg)!=SQLITE_OK)
	{
		printf("stu select fail:%s\n",errmsg);
		sqlite3_free(errmsg);
		return 1;
	}
	printf("select have done\n");
	return 0;
}
int do_select_2(sqlite3 *ppdb)
{
	char sql[128]="select * from stu;";
	char **pazresult=NULL;
	int cols=0;
	int rows=0;
	char *errmsg=NULL;
	if(sqlite3_get_table(ppdb,sql,&pazresult,&rows,&cols,&errmsg)!=SQLITE_OK)
	{
		printf("stu select fail:%s\n",errmsg);
		sqlite3_free(errmsg);
		return 1;
	}
	for(int i=0;i<rows+1;i++)
	{
		for(int j=0;j<cols;j++)
		{
			printf("%s\t",pazresult[i*cols+j]);
		}
		printf("\n");
	}
	sqlite3_free_table(pazresult);
	return 0;
}
int do_delete(sqlite3 *ppdb)
{
	int id;
	printf("enter the student id u want to delete:");
	scanf("%d",&id);
	getchar();
	char sql[128]="";
	char *errmsg=NULL;
	snprintf(sql,sizeof(sql),"delete from stu where id=%d;",id);
	if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
	{
		printf("stu delete fail:%s\n",errmsg);
		sqlite3_free(errmsg);
		return 1;
	}
	printf("delete have done\n");
	return 0;
}
int do_update(sqlite3 *ppdb)
{
	int id;
	int newid;
	char name[20];
	int age;
	double score;
	int column;
	printf("enter the id u want to update:");
	scanf("%d",&id);
	getchar();
	char sql[128]="";
	char *errmsg=NULL;
	printf("enter the column u want to update:");
	scanf("%d",&column);
	getchar();
	switch(column)
	{
	case 1:
		{
			printf("enter the new id:");
			scanf("%d",&newid);
			getchar();
			snprintf(sql,sizeof(sql),"update stu set id = %d where id = %d;",newid,id);
			if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
			{
				printf("stu update fail:%s\n",errmsg);
				sqlite3_free(errmsg);
				return 1;
			}
			printf("update have done\n");
		}
		break;
	case 2:
		{
			printf("enter the new name:");
			scanf("%s",name);
			getchar();
			snprintf(sql,sizeof(sql),"update  stu set name = \"%s\" where id = %d ;",name,id);
			if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
			{
				printf("stu update fail:%s\n",errmsg);
				sqlite3_free(errmsg);
				return 1;
			}
			printf("update have done\n");
		}
		break;
	case 3: 		
		{
			printf("enter the new age:");
			scanf("%d",&age);
			getchar();
			snprintf(sql,sizeof(sql),"update  stu set age = %d where id = %d;",age,id);
			if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
			{
				printf("stu update fail:%s\n",errmsg);
				sqlite3_free(errmsg);
				return 1;
			}
			printf("update have done\n");
		}
		break;
	case 4:
		{
			printf("enter the new score:");
			scanf("%lf",&score);
			getchar();
			snprintf(sql,sizeof(sql),"update stu set score = %.2lf  where id = %d;",score,id);
			if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
			{
				printf("stu update fail:%s\n",errmsg);
				sqlite3_free(errmsg);
				return 1;
			}
			printf("update have done\n");
		}
		break;
	default:printf("argument error\n");
			break;
	}
	return 0;
}

int main(int argc, const char *argv[])
{
	sqlite3 *ppdb=NULL;
	if(sqlite3_open("02.db",&ppdb)!=SQLITE_OK)
	{
		printf("open error:%d,%s\n",sqlite3_errcode(ppdb),sqlite3_errmsg(ppdb));
		return 1;
	}
	printf("the sqlite has been opened\n");
	char sql[128]="create table if not exists stu(id int,name text,age int,score real);";
	char *errmsg=NULL;
	if(sqlite3_exec(ppdb,sql,NULL,NULL,&errmsg)!=SQLITE_OK)
	{
		printf("stu create fail:%s\n",errmsg);
		sqlite3_free(errmsg);
		return 1;
	}
	printf("table stu create success\n");
	int menu=0;
	while(1)
	{
		system("clear");
		printf("\t\t========student information mange system===========\n");
		printf("\t\t=============   1.add  ================\n");
		printf("\t\t=============  2.delete ================\n");
		printf("\t\t=============  3.update   ================\n");
		printf("\t\t=============  4.select  ================\n");
		printf("\t\t=============   5.exit     ================\n");
		printf("enter ur choice:");
		scanf("%d",&menu);
		getchar();
		switch (menu)
		{
		case 1:
			{
				do_add(ppdb);
			}
			break;
		case 2:
			{
				do_delete(ppdb);
			}
			break;
		case 3:
			{
				do_update(ppdb);
			}
			break;
		case 4:
			{
				//do_select(ppdb);
				do_select_2(ppdb);
			}
			break;
		case 5:goto END;
		default:printf("error argument\n");
		}
		printf("enter \"enter\" to clear the scream\n");
		while(getchar()!='\n');
	}
END:
	sqlite3_close(ppdb);
	return 0;
}