So verbinden Sie eine mySQL-Datenbank mit C++

Ich versuche, die Datenbank von meiner Website zu verbinden und einige Zeilen mit C++ anzuzeigen.
Also versuche ich im Grunde, eine Anwendung zu erstellen, die eine ausgewählte Abfrage aus einer Tabelle aus meiner Site-Datenbank ausführt. Nun, das muss möglich sein, weil ich unzählige Anwendungen gesehen habe, die das tun.

Wie mache ich das? Kann jemand ein Beispiel machen und mir sagen, welche Bibliotheken ich verwenden sollte?

Antworten:

Hier gefunden:

/* Standard C++ includes */
 #include <stdlib.h>
 #include <iostream>
 /*
   Include directly the different
   headers from cppconn/ and mysql_driver.h + mysql_util.h
   (and mysql_connection.h). This will reduce your build time!
 */
 #include "mysql_connection.h"
 #include <cppconn/driver.h>
 #include <cppconn/exception.h>
 #include <cppconn/resultset.h>
 #include <cppconn/statement.h>
 using namespace std;
 int main(void)
 {
 cout << endl;
 cout << "Running 'SELECT 'Hello World!' »
    AS _message'..." << endl;
 try {
   sql::Driver *driver;
   sql::Connection *con;
   sql::Statement *stmt;
   sql::ResultSet *res;
   /* Create a connection */
   driver = get_driver_instance();
   con = driver->connect("tcp://127.0.0.1:3306", "root", "root");
   /* Connect to the MySQL test database */
   con->setSchema("test");
   stmt = con->createStatement();
   res = stmt->executeQuery("SELECT 'Hello World!' AS _message"); // replace with your statement
   while (res->next()) {
     cout << "\t... MySQL replies: ";
     /* Access column data by alias or column name */
     cout << res->getString("_message") << endl;
     cout << "\t... MySQL says it again: ";
     /* Access column fata by numeric offset, 1 is the first column */
     cout << res->getString(1) << endl;
   }
   delete res;
   delete stmt;
   delete con;
 } catch (sql::SQLException &e) {
   cout << "# ERR: SQLException in " << __FILE__;
   cout << "(" << __FUNCTION__ << ") on line " »
      << __LINE__ << endl;
   cout << "# ERR: " << e.what();
   cout << " (MySQL error code: " << e.getErrorCode();
   cout << ", SQLState: " << e.getSQLState() << " )" << endl;
 }
 cout << endl;
 return EXIT_SUCCESS;
 }
 

Einige Code-Antworten

wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm rpm -ivh mysql-community-release-el7-5.noarch.rpm yum update yum install mysql-server 

systemctl start mysqld

systemctl status mysqld

mysql -u root -p

CREATE DATABASE mydb;

USE mydb;

CREATE TABLE my_table (table_id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, first_name TEXT, last_name TEXT);

INSERT INTO my_table(first_name, last_name) VALUES('Cristiano', 'Ronaldo');
INSERT INTO my_table(first_name, last_name) values('Lionel', 'Messi');

SELECT * FROM my_table;

yum info mysql-devel

yum install mysql-devel

#include <mysql.h>
#include <stdio.h>
 int main() {  MYSQL *conn;
 MYSQL_RES *res;
 MYSQL_ROW row;
  char *server = "localhost";
 char *user = "root";
 char *password = "";
/*password is not set in this example*/  char *database = "mydb";
  conn = mysql_init(NULL);
  /* Connect to database */  if (!mysql_real_connect(conn, server,  user, password, database, 0, NULL, 0))  {    printf("Failed to connect MySQL Server %s. Error: %s\n", server, mysql_error(conn));
   return 0;
 }   /* Execute SQL query to fetch all table names.*/  if (mysql_query(conn, "show tables"))  {    printf("Failed to execute quesry. Error: %s\n", mysql_error(conn));
   return 0;
 }   res = mysql_use_result(conn);
  /* Output table name */  printf("MySQL Tables in mydb database:\n");
 while ((row = mysql_fetch_row(res)) != NULL)  printf("%s \n", row[0]);
  /* free results */  mysql_free_result(res);
  /* send SQL query */  if (mysql_query(conn, "select * from my_table"))  {    printf("Failed to execute quesry. Error: %s\n", mysql_error(conn));
   return 0;
 }   res = mysql_store_result(conn);
 if (res == NULL)  {    return 0;
 }   int columns = mysql_num_fields(res);
  int i = 0;
  printf("Entries in the table my_table:\n");
 while(row = mysql_fetch_row(res))  {    for (i = 0;
i <
columns;
i++)    {
printf("%s ", row[i] ? row[i] : "NULL");
   }    printf("\n");
 }   mysql_free_result(res);
 mysql_close(conn);
  return 1;
} 

 conn = mysql_init(NULL);
  /* Connect to database */  if (!mysql_real_connect(conn, server,  user, password, database, 0, NULL, 0))  {    printf("Failed to connect MySQL Server %s. Error: %s\n", server, mysql_error(conn));
   return 0;
 } 

/* Execute SQL query to fetch all table names.*/  if (mysql_query(conn, "show tables"))  {    printf("Failed to execute quesry. Error: %s\n", mysql_error(conn));
   return 0;
 }   res = mysql_use_result(conn);
  /* Output table name */  printf("MySQL Tables in mydb database:\n");
 while ((row = mysql_fetch_row(res)) != NULL)  printf("%s \n", row[0]);
  /* free results */  mysql_free_result(res);

if (mysql_query(conn, "select * from my_table"))  {    printf("Failed to execute quesry. Error: %s\n", mysql_error(conn));
   return 0;
 }   res = mysql_store_result(conn);
 if (res == NULL)  {    return 0;
 } 

int columns = mysql_num_fields(res);
  int i = 0;
  printf("Entries in the table my_table:\n");
 while(row = mysql_fetch_row(res))  {    for (i = 0;
i <
columns;
i++)    {
printf("%s ", row[i] ? row[i] : "NULL");
   }    printf("\n");
 } 

./mysqlc MySQL Tables in mysql database: my_table 1 Cristiano Ronaldo 2 Lionel Messi