[大数据]C++ 操作Mysql

C++ 操作Mysql

1. 安装mysql

sudo apt install mysql-server
sudo apt-get install mysql-client
sudo apt-get install libmysqld-dev

2. 编译指令

先使用mysql_config --libs 检查mysql链接的类库

ljn@ljn-virtual-machine:~/文档/demo$ mysql_config --libs
-L/usr/lib/x86_64-linux-gnu -lmysqlclient -lpthread -lz -lm -lrt -lssl -lcrypto -ldl

在makefile中新增链接指令

mydb:main.cc
	g++  main.cc -o mydb  -L/usr/lib/x86_64-linux-gnu -lmysqlclient -lpthread -lz -lm -lrt -lssl -lcrypto -ldl

3. 数据库操作类

class Db
{
public:
    Db(const string &host, const string &username, const string &password, const string &db)
    {
        conn = mysql_init(NULL);
        if (conn == NULL)
            goto error;

        conn = mysql_real_connect(conn, host.c_str(),
                                  username.c_str(), password.c_str(), db.c_str(), 0, NULL, 0);

        if (conn == NULL)
            goto error;

        return;

    error:
        cout << "error" << endl;
        exit(-1);
    }

    ~Db()
    {
        if (conn != NULL)
            mysql_close(conn);
    };

    void query(const string &sql)
    {
        MYSQL_RES *res = NULL;
        MYSQL_ROW row = NULL;
        int ret = mysql_query(conn, sql.c_str());
        if (ret == -1){
            goto error;
        }
        res = mysql_store_result(conn);
        printf("number of dataline returned: %d\n", mysql_affected_rows(conn));
        for(int i = 0;i<res->field_count;i++)
            printf("%s  ",res->fields[i].name);
        printf("\n");

        while(row =mysql_fetch_row(res)){
            for(int i = 0;i<res->field_count;i++)
                cout<<row[i]<<" ";
            cout<<endl;    
        }
        return;

        error:
        cout << "error" << endl;
        exit(-1);
    }

private:
    MYSQL *conn;
};