嘉峪关网站建设,全球搜效果怎么样,深圳找工作哪个网站好,创业做网站开发实验内容#xff1a; 假如我家开了个水果超市#xff0c;有以下水果#xff0c;想实现自动化管理#xff0c;扫描二维码就能知道当前的水果状态#xff0c;进货几天了#xff0c; 好久需要再次进货#xff0c;那些水果畅销#xff0c;那些水果不畅销#xff0c;那些水…实验内容 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 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。 相关API 可以看看3sqlite3 数据库 C语言 API 实现流程 首先创建一张数据表fruit除了需要指定每条记录的唯一标识id外还要有水果品类(name)、存量(weight)、价格(price)、最近交易时间(time)等字段。 每一次操作都会改变表中的数据内容这些我们通过API来实现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。 实现代码
fruit.h
#ifndef _FRUIT_H_
#define _FRUIT_H_#include stdio.h
#include sqlite3.h
#include string.h
#include stdlib.h
#include time.h#define N 128
#define DATABASE fruitery.db
#define TABLE fruitint do_insert(sqlite3 *db, char *buf);
int do_query(sqlite3 *db);
int do_update_weight(sqlite3 *db, char * buf);
int do_update_price(sqlite3 *db, char * buf);
int do_delete(sqlite3 *db, char *buf);
int do_delete_sort(sqlite3 *db, char * buf, int id);#endiffruit.c
#include fruit.hint do_insert(sqlite3 *db, char *buf) {char *errmsg;char sql[N] {};char name[N] {};float weight;float price;printf(Input fruit name:);scanf(%s, name);getchar();printf(Input weight:);scanf(%f, weight);printf(Input price:);scanf(%f, price);sprintf(sql, insert into %s (name, weight, price, time) values(%s, %.3f, %.3f, %s), TABLE, name, weight, price, buf);if ( sqlite3_exec(db, sql, NULL, NULL, errmsg) ! SQLITE_OK) {printf(Error: %s\n, errmsg);} else {printf(insert done.\n);}return 0;
}int callback (void* arg,int f_num ,char** f_value,char** f_name) {int i;for(i 0; i f_num; i) {printf(%-8s, f_value[i]);}return 0;
}int do_query(sqlite3 *db) {char *errmsg;char sql[N] {};sprintf(sql, select * from %s, TABLE);if ( sqlite3_exec(db, sql, callback, NULL, errmsg) ! SQLITE_OK) {printf(Error: %s\n, errmsg);} else {printf(query done.\n);}return 0;
}int do_update_weight(sqlite3 *db, char * buf)
{char *errmsg;char sql[N] {};float weight;int id;printf(Input id:);scanf(%d, id);printf(Input weight:);scanf(%f, weight);sprintf(sql, update %s set weight %.3f, time %s where id %d, TABLE, weight, buf, id);if ( sqlite3_exec(db, sql, NULL, NULL, errmsg) ! SQLITE_OK) {printf(Error: %s\n, errmsg);} else {printf(update weight done.\n);}return 0;
}int do_update_price(sqlite3 *db, char * buf)
{char *errmsg;char sql[N] {};float price;int id;printf(Input id:);scanf(%d, id);printf(Input price:);scanf(%f, price);sprintf(sql, update %s set price %.3f, time %s where id %d, TABLE, price, buf, id);if ( sqlite3_exec(db, sql, NULL, NULL, errmsg) ! SQLITE_OK) {printf(Error: %s\n, errmsg);} else {printf(update price done.\n);}return 0;
}int do_delete(sqlite3 *db, char * buf)
{char *errmsg;char sql[N] {};int id;printf(Input id:);scanf(%d, id);do_delete_sort(db, buf, id );sprintf(sql, delete from %s where id %d, TABLE, id);if ( sqlite3_exec(db, sql, NULL, NULL, errmsg) ! SQLITE_OK) {printf(Error: %s\n, errmsg);} else {printf(delete done.\n);}return 0;}#define NEW_TABLE new_table
int do_delete_sort(sqlite3 *db, char *buf, int id)
{char *errmsg;char sql[N] {};//创建一张临时的新表格sprintf(sql, create table %s(id integer primary key autoincrement, name char, weight float, price float, time char);, NEW_TABLE);sqlite3_exec(db, sql, NULL, NULL, errmsg);memset(sql, 0, sizeof(sql));//sprintf(sql, insert into %s select * from %s where id %d;,NEW_TABLE, TABLE, id);sqlite3_exec(db, sql, NULL, NULL, errmsg);memset(sql, 0, sizeof(sql));//删除原有的表sprintf(sql, drop table %s, TABLE);sqlite3_exec(db, sql, NULL, NULL, errmsg);memset(sql, 0, sizeof(sql));//将新表的名字改成原有的旧表的名字sprintf(sql, alter table %s rename to %s, NEW_TABLE, TABLE);sqlite3_exec(db, sql, NULL, NULL, errmsg);memset(sql, 0, sizeof(sql));return 0;
}
test.c
#include fruit.hint main (int argc, char *argv[]) {sqlite3 *db;char *errmsg;char buf[N] {};char sql[N] {};int n;time_t t;struct tm *tp;//打开数据库文件 if ( sqlite3_open(DATABASE, db) ! SQLITE_OK ) {printf(%s\n, errmsg);return -1;} else {printf(open DATABASE success.\n);}
//创建一张数据库表格sprintf(sql, create table %s(id integer primary key autoincrement, name char, weight float, price float, time char);, TABLE);if ( sqlite3_exec(db, sql, NULL, NULL, errmsg) ! SQLITE_OK) {printf(exec :%s\n, errmsg);} else {printf(create table success.\n);}//时间time(t);tp localtime(t);sprintf(buf,%d-%02d-%02d %02d:%02d:%02d\n,tp-tm_year1900, tp-tm_mon1,tp-tm_mday, tp-tm_hour, tp-tm_min, tp-tm_sec);printf(%s\n, buf);while (1) {printf(-------------------------------------------\n);printf(1: insert 2:query 3:trade 4:update 5:delete 6:quit\n);printf(-------------------------------------------\n);printf(Please select:);scanf(%d, n);switch(n) {case 1: do_insert(db, buf);break;case 2:do_query(db);break;case 3:do_update_weight(db, buf);break;case 4:do_update_price(db, buf);break;case 5:do_delete(db, buf);break;case 6:printf(main exit.\n);sqlite3_close(db);exit(0);break;default :printf(Invalid data,\n);}}return 0;
}
实现结果
