How to connect mySQL database using C++

I'm trying to connect the database from my website and display some rows using C++. So bascily I'm trying to make an application that does a select query from a table from my site database. Now, this must be possible because I've seen tons of applications doing it.

How do I do this? Can some one make an example and tell me what libraries I should be using?

Solution 1:

Found here:

/* 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;
}

Solution 2:

Finally I could successfully compile a program with C++ connector in Ubuntu 12.04 I have installed the connector using this command

'apt-get install libmysqlcppconn-dev'

Initially I faced the same problem with "undefined reference to `get_driver_instance' " to solve this I declare my driver instance variable of MySQL_Driver type. For ready reference this type is defined in mysql_driver.h file. Here is the code snippet I used in my program.

sql::mysql::MySQL_Driver *driver;
try {     
    driver = sql::mysql::get_driver_instance();
}

and I compiled the program with -l mysqlcppconn linker option

and don't forget to include this header

#include "mysql_driver.h" 

Solution 3:

Yes, you will need the mysql c++ connector library. Read on below, where I explain how to get the example given by mysql developers to work.

Note(and solution): IDE: I tried using Visual Studio 2010, but just a few sconds ago got this all to work, it seems like I missed it in the manual, but it suggests to use Visual Studio 2008. I downloaded and installed VS2008 Express for c++, followed the steps in chapter 5 of manual and errors are gone! It works. I'm happy, problem solved. Except for the one on how to get it to work on newer versions of visual studio. You should try the mysql for visual studio addon which maybe will get vs2010 or higher to connect successfully. It can be downloaded from mysql website

Whilst trying to get the example mentioned above to work, I find myself here from difficulties due to changes to the mysql dev website. I apologise for writing this as an answer, since I can't comment yet, and will edit this as I discover what to do and find the solution, so that future developers can be helped.(Since this has gotten so big it wouldn't have fitted as a comment anyways, haha)

@hd1 link to "an example" no longer works. Following the link, one will end up at the page which gives you link to the main manual. The main manual is a good reference, but seems to be quite old and outdated, and difficult for new developers, since we have no experience especially if we missing a certain file, and then what to add.

@hd1's link has moved, and can be found with a quick search by removing the url components, keeping just the article name, here it is anyways: http://dev.mysql.com/doc/connector-cpp/en/connector-cpp-examples-complete-example-1.html

Getting 7.5 MySQL Connector/C++ Complete Example 1 to work

Downloads:

-Get the mysql c++ connector, even though it is bigger choose the installer package, not the zip.

-Get the boost libraries from boost.org, since boost is used in connection.h and mysql_connection.h from the mysql c++ connector

Now proceed:

-Install the connector to your c drive, then go to your mysql server install folder/lib and copy all libmysql files, and paste in your connector install folder/lib/opt

-Extract the boost library to your c drive

Next:

It is alright to copy the code as it is from the example(linked above, and ofcourse into a new c++ project). You will notice errors:

-First: change

cout << "(" << __FUNCTION__ << ") on line " »
 << __LINE__ << endl;

to

cout << "(" << __FUNCTION__ << ") on line " << __LINE__ << endl;

Not sure what that tiny double arrow is for, but I don't think it is part of c++

-Second: Fix other errors of them by reading Chapter 5 of the sql manual, note my paragraph regarding chapter 5 below

[Note 1]: Chapter 5 Building MySQL Connector/C++ Windows Applications with Microsoft Visual Studio If you follow this chapter, using latest c++ connecter, you will likely see that what is in your connector folder and what is shown in the images are quite different. Whether you look in the mysql server installation include and lib folders or in the mysql c++ connector folders' include and lib folders, it will not match perfectly unless they update the manual, or you had a magic download, but for me they don't match with a connector download initiated March 2014.

Just follow that chapter 5,

-But for c/c++, General, Additional Include Directories include the "include" folder from the connector you installed, not server install folder

-While doing the above, also include your boost folder see note 2 below

-And for the Linker, General.. etc use the opt folder from connector/lib/opt

*[Note 2]*A second include needs to happen, you need to include from the boost library variant.hpp, this is done the same as above, add the main folder you extracted from the boost zip download, not boost or lib or the subfolder "variant" found in boostmainfolder/boost.. Just the main folder as the second include

Next:

What is next I think is the Static Build, well it is what I did anyways. Follow it.

Then build/compile. LNK errors show up(Edit: Gone after changing ide to visual studio 2008). I think it is because I should build connector myself(if you do this in visual studio 2010 then link errors should disappear), but been working on trying to get this to work since Thursday, will see if I have the motivation to see this through after a good night sleep(and did and now finished :) ).

Solution 4:

I had to include -lmysqlcppconn to my build in order to get it to work.