初学者VS操作MYSQL数据库

定义数据库操作类

class Mysql {
public:
/***************************连接数据库***************************/
	MYSQL *mysqlConnect(conn_info con) {
		MYSQL *mysql = mysql_init(NULL);	//mysql初始化函数，实例化一个新的对象（NULL为新的对象，否则为初始化以创建的对象)
		if (!mysql_real_connect(mysql, con.host, con.user, con.password, con.database, 3306, NULL, 0)) {	//mysql_real_connect(MYSQL *mysql,const char *host, const char *user, const char *passwd, const char *db, unsigned int port, const char *unix_socket, unsigned long client_flag)
			cout << "connection error";
			exit(1);
		}
		cout << "connection success" << endl;
		return mysql;	//返回实例化的对象
	}

/**************************数据库操作函数**************************/
	void mysqlOperation(MYSQL *mysql, char *sql_op) {
		if (mysql_query(mysql, sql_op)) {		//mysql_query()函数为对mysql进行操作，第一个参数为刚才实例化的对象，第二个位需要进行的操作
			printf("MySQL query error : %s", mysql_error(mysql));
			getchar();
			exit(1);
		}
	}

/*****************************修改数据****************************/
	void updateData(MYSQL *mysql, const char *tableNames, const char *col, int data, int id) {
		char cmd[100];

		char data2[5];
		char id2[5];
		const char *data2s = itoa(data, data2, 10);
		const char *id2s = itoa(id, id2, 10);

		strcpy(cmd, "update ");
		strcat(cmd, tableNames);
		strcat(cmd, " set ");
		strcat(cmd, col);
		strcat(cmd, "=");
		strcat(cmd, data2s);
		strcat(cmd, " where id");
		strcat(cmd, "=");
		strcat(cmd, id2s);
		strcat(cmd, "");

		mysqlOperation(mysql, cmd);
	}

/*****************************查询函数****************************/
	MYSQL_RES *mysqlSelect(MYSQL *mysql, const char *table, MYSQL_RES *res) {
		char cmd[100];

		strcpy(cmd, "select * from ");
		strcat(cmd, table);		//拼接指令

		mysql_free_result(res);
		mysqlOperation(mysql, cmd);
		return mysql_store_result(mysql);//查询的结果,用mysql_store_result函数后接mysql_affected_rows()可以返回查询次数，而用mysql_use_result()则不行
	}

/****************************显示所有数据***************************/
	void mysqlShow(MYSQL_RES *res, vector<string> &colName) {
		MYSQL_ROW col;
		while ((col = mysql_fetch_row(res)) != NULL)	//	row = mysql_fetch_row(res);进行数据的转换,需要循环转换
		{
			for (int i =0; i < colName.size(); i++)
				cout << col[i] << "  ";	//显示的行数,注意此处表格中只有两列，故row也只有2列，若写多列会出错
			cout << endl;
		}
	}

创建表格

//创建表格
class TableOperation: public Mysql {
public:
	MYSQL *connectTbale() {
		MYSQL *conn;//用于实例化的新的对象

		struct conn_info info;
		Mysql mysql;

		info.host = "localhost";
		info.user = "root";
		info.password = "111111";
		info.database = "gy1";	//我的数据库名字

		conn = mysql.mysqlConnect(info);	//连接数据库

		return conn;
	}

	void updateAllData(MYSQL *mysql, const char *tableName, const char *colName,vector<int> data, vector<string> &col) {
		for (int i = 0; i < data.size(); i++) {
			updateData(mysql, tableName, colName, data[i], i + 1);
		}
	}

	void showAllData(MYSQL *mysql, const char *tableName, vector<string> &colName) {
		MYSQL_RES *res;
		res = NULL;//要先初始化，否则会报错
		for (vector<string>::const_iterator iter = colName.begin(); iter != colName.end(); ++iter)
			cout << *iter << " ";
		cout << endl;
		res = mysqlSelect(mysql, tableName, res);
		mysqlShow(res, colName);
	}
};

测试程序

//	id	name	gender	score	
//	1	std1	1		60
//	2	std2	0		70
//	3	std3	1		80

struct conn_info {
	char *host;
	char *user;
	char *password;
	char *database;
};

int main() {
	string colName[4] = { "id", "name", "gender", "score" };
	int scoreData[4] = { 55, 65, 75, 85 };
	int genderDate[4] = { 0, 1, 0, 0 };

	vector<string> colname(colName,colName+4);
	vector<int> scoredata(scoreData, scoreData + 4);
	vector<int> genderdata(genderDate, genderDate + 4);

	TableOperation tableOperation;

	MYSQL *conn;
	conn = tableOperation.connectTbale();
	tableOperation.updateAllData(conn, "student", "score", scoredata, colname);
	tableOperation.updateAllData(conn, "student", "gender", genderdata, colname);
	tableOperation.showAllData(conn, "student", colname);

	system("pause");
	mysql_close(conn);//断开连接
	return 0;
}

本程序仅供参考，如有错误请见谅。