C++ 操作数据库 经典案例

//下面的代码是一个实现C++连接MYSQL数据库的很好的例子
//这里用了建表，插入，检索，删表等常用功能
//我用VC++6.0生成，已经成功连接了。
//在VC++6.0中要想把做一下两步准备工作才可以。
//(1)Tools->Options->Directories->Include files中添加C:\Program Files\MySQL\MySQL Server 6.0\include
//(2)Tools->Options->Directories->Library files中添加C:\Program Files\MySQL\MySQL Server 6.0\lib\opt
//其实就是将头文件和库文件包含进来
//我觉得这个例子写的很好，再结合自己的试验，特地介绍给大家！
 
#include 
#include 
#include 
#include 
using namespace std;
 
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib, "libmysql.lib")
 
//单步执行，不想单步执行就注释掉
#define STEPBYSTEP
 
int main() {
    cout << "****************************************" << endl;
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //必备的一个数据结构
    MYSQL mydata;
 
    //初始化数据库
    if (0 == mysql_library_init(0, NULL, NULL)) {
        cout << "mysql_library_init() succeed" << endl;
    } else {
        cout << "mysql_library_init() failed" << endl;
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //初始化数据结构
    if (NULL != mysql_init(&mydata)) {
        cout << "mysql_init() succeed" << endl;
    } else {
        cout << "mysql_init() failed" << endl;
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //在连接数据库之前，设置额外的连接选项
    //可以设置的选项很多，这里设置字符集，否则无法处理中文
    if (0 == mysql_options(&mydata, MYSQL_SET_CHARSET_NAME, "gbk")) {
        cout << "mysql_options() succeed" << endl;
    } else {
        cout << "mysql_options() failed" << endl;
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //连接数据库
    if (NULL
            != mysql_real_connect(&mydata, "localhost", "root", "test", "test",
                    3306, NULL, 0))
            //这里的地址，用户名，密码，端口可以根据自己本地的情况更改
            {
        cout << "mysql_real_connect() succeed" << endl;
    } else {
        cout << "mysql_real_connect() failed" << endl;
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //sql字符串
    string sqlstr;
 
    //创建一个表
    sqlstr = "CREATE TABLE IF NOT EXISTS user_info";
    sqlstr += "(";
    sqlstr +=
            "user_id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY COMMENT 'Unique User ID',";
    sqlstr +=
            "user_name VARCHAR(100) CHARACTER SET gb2312 COLLATE gb2312_chinese_ci NULL COMMENT 'Name Of User',";
    sqlstr +=
            "user_second_sum INT UNSIGNED NOT NULL DEFAULT 0 COMMENT 'The Summation Of Using Time'";
    sqlstr += ");";
    if (0 == mysql_query(&mydata, sqlstr.c_str())) {
        cout << "mysql_query() create table succeed" << endl;
    } else {
        cout << "mysql_query() create table failed" << endl;
        mysql_close(&mydata);
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //向表中插入数据
    sqlstr =
            "INSERT INTO user_info(user_name) VALUES('公司名称'),('一级部门'),('二级部门'),('开发小组'),('姓名');";
    if (0 == mysql_query(&mydata, sqlstr.c_str())) {
        cout << "mysql_query() insert data succeed" << endl;
    } else {
        cout << "mysql_query() insert data failed" << endl;
        mysql_close(&mydata);
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //显示刚才插入的数据
    sqlstr = "SELECT user_id,user_name,user_second_sum FROM user_info";
    MYSQL_RES *result = NULL;
    if (0 == mysql_query(&mydata, sqlstr.c_str())) {
        cout << "mysql_query() select data succeed" << endl;
 
        //一次性取得数据集
        result = mysql_store_result(&mydata);
        //取得并打印行数
        int rowcount = mysql_num_rows(result);
        cout << "row count: " << rowcount << endl;
 
        //取得并打印各字段的名称
        unsigned int fieldcount = mysql_num_fields(result);
        MYSQL_FIELD *field = NULL;
        for (unsigned int i = 0; i < fieldcount; i++) {
            field = mysql_fetch_field_direct(result, i);
            cout << field->name << "\t\t";
        }
        cout << endl;
 
        //打印各行
        MYSQL_ROW row = NULL;
        row = mysql_fetch_row(result);
        while (NULL != row) {
            for (int i = 0; i < fieldcount; i++) {
                cout << row[i] << "\t\t";
            }
            cout << endl;
            row = mysql_fetch_row(result);
        }
 
    } else {
        cout << "mysql_query() select data failed" << endl;
        mysql_close(&mydata);
        return -1;
    }
 
#ifdef STEPBYSTEP
    system("pause");
#endif
 
    //删除刚才建的表
    sqlstr = "DROP TABLE user_info";
    if (0 == mysql_query(&mydata, sqlstr.c_str())) {
        cout << "mysql_query() drop table succeed" << endl;
    } else {
        cout << "mysql_query() drop table failed" << endl;
        mysql_close(&mydata);
        return -1;
    }
    mysql_free_result(result);
    mysql_close(&mydata);
    mysql_server_end();
 
    system("pause");
    return 0;
}