基于SQLITE实现水果超市的货物数据管理

功能：假如我家开了个水果超市，有以下水果，想实现自动化管理，扫描二维码就能知道当前的水果状态，进货几天了，
好久需要再次进货，那些水果畅销，那些水果不畅销，那些水果春夏秋冬的价格波动，好，那么现在我想将
这些信息保存在数据库中，那么我应该怎么做；
提示： 建立一张fruit表，
假如水果有： 苹果，香蕉，梨，橘子，葡萄....（可以自己查一下英文保存到数据库）
水果价格： 苹果 5元/斤 香蕉 3元/斤 梨 3.5元/斤 橘子2.5元/斤 葡萄 8元/斤....
当前存货： 苹果 80斤 香蕉 200斤 梨 50斤 橘子300斤 葡萄 100斤....
超市每天水果都有进货和卖出嘛，水果的价格随着季节和天气也会有波动，顾客也会看一下每天水果的价格的嘛，
所以要求，根据上述提示，利用数据库完成水果店各种水果的增（进货）删（卖出）改（波动）查（看价格）功能。

并将进出货的时间和顾客光顾的时间记录到数据库中保存。

代码如下

#include 
#include 
#include 
#include 


int do_insert(sqlite3 * db)
{
	char catagory[32]={0};
	float price;
	int inventory;
	char incometime[32]={0};
	char * errmsg;
	char sql[1024] = {0};
	printf("plz input catagory:");
	scanf("%s",catagory);
	getchar();

	printf("plz input price:");
	scanf("%f",&price);
	getchar();
	
	printf("plz input inventory:");
	scanf("%d",&inventory);
	getchar();

	printf("plz input incometime:");
	scanf("%s",incometime);
	getchar();

	sprintf(sql,"insert into fruit(catagory,price,inventory,incometime) values('%s',%f,%d,'%s');",catagory,price,inventory,incometime);
	printf("%s",sql);
	if(sqlite3_exec(db,sql,NULL,NULL,&errmsg) != SQLITE_OK)
	{
		if(strstr(errmsg,"UNIQUE") == NULL)
		{
			printf("%s\n",errmsg);
			return -1;
		}
		sprintf(sql,"update fruit set price = %f, inventory = %d, incometime = '%s' where catagory = '%s';",price,inventory,incometime,catagory);
		if(sqlite3_exec(db,sql,NULL,NULL,&errmsg) != SQLITE_OK)
		{
			printf("%s\n",errmsg);
			return -1;
		}
	}
	printf("insert successfully\n");
	return 0;
}

 
int do_delete(sqlite3 * db)
{
	char catagory[32] = {0};
	int inventory;
	char saletime[32]  = {0};
	char * errmsg;
	char sql[1024] = {0};
	printf("plz input catagory:");
	scanf("%s",catagory);
	getchar();

	printf("plz input inventory:");
	scanf("%d",&inventory);
	getchar();
	
	printf("plz input saletime:");
	scanf("%s",saletime);

	sprintf(sql,"update fruit set inventory = %d,saletime = '%s' where catagory = '%s';",inventory,saletime,catagory);
	if(sqlite3_exec(db,sql,NULL,NULL,&errmsg) != SQLITE_OK)
	{
		printf("%s\n",errmsg);
		return -1;
	}
	return 0;
}

int do_update(sqlite3 * db)
{
	char catagory[32] = {0};
	float price;
	char * errmsg;
	char sql[1024] = {0};
	printf("plz input catagory:");
	scanf("%s",catagory);
	getchar();

	printf("plz input price:");
	scanf("%f",&price);
	getchar();
	
	sprintf(sql,"update fruit set price = %f where catagory = '%s';",price,catagory);
	if(sqlite3_exec(db,sql,NULL,NULL,&errmsg) != SQLITE_OK)
	{
		printf("%s\n",errmsg);
		return -1;
	}
	return 0;
}

int callback(void * arg,int f_num,char ** f_value,char ** f_name)
{
	printf("price:%s\n",f_value[1]);
	return 0;
}

int do_query(sqlite3 * db)
{
	char catagory[32] = {0};
	float price;
	char * errmsg;
	char sql[1024] = {0};
	printf("plz input catagory:");
	scanf("%s",catagory);
	getchar();
	
	sprintf(sql,"select * from fruit where catagory = '%s';",catagory);
	if(sqlite3_exec(db,sql,callback,NULL,&errmsg) != SQLITE_OK)
	{
		printf("%s\n",errmsg);
		return -1;
	}
	return 0;
}
int main()
{
	sqlite3 * db;
	char * errmsg;
	//打开数据库
	if(sqlite3_open("./fruit.db",&db) != SQLITE_OK)
	{
		printf("%s\n",sqlite3_errmsg(db));
		exit(-1);
	}
	//新建表
	if(sqlite3_exec(db,"create table fruit (catagory char unique, price float, inventory Interger, incometime char,saletime char);",NULL,NULL,&errmsg) != SQLITE_OK)
	{
		printf("%s\n",errmsg);
		exit(-1);
	}
	int cmd;
	while(1)
	{
		printf("1:insert 2:delete 3:update 4:query 5:quit\n");
		printf("plz input the number\n");
		scanf("%d",&cmd);
		getchar();
		switch(cmd)
		{
			case 1:
				do_insert(db);
				break;
			case 2:
				do_delete(db);
				break;
			case 3:
				do_update(db);
				break;
			case 4:
				do_query(db);
				break;
			case 5:
				sqlite3_close(db);
				exit(0);
			default:
				printf("cmd error\n");

		}
	}
	return 0;
}