/////
// Connects to MySQL database server from
// C or C++ program.
/////
/////////////////////////////////////////////
// //
// Connecting C++ Win32 App To MySQL //
// //
// You found this at bobobobo's weblog, //
// https://bobobobo.wordpress.com //
// //
// Creation date: Apr 5/09 //
// Last modified: Apr 5/09 //
// //
/////////////////////////////////////////////
// !! Note! I've included copies of the MySQL
// include headers and library files.. I've done this
// so that the project will compile and run
// more easily for you, but this DOES NOT mean
// that you should skip the SETUP-Y stuff section
// below!
// If you want MySQL to work easily for you in new
// projects, you really should set up Visual Studio
// as explained below.
#pragma region all the setup-y stuff
/////////
// MAKINET WORK: (any prince of persia 2 the shadow and the flame fans out there?)
//
// 1) First, you OBVIOUSLY must install MySQL.
// Be sure to download the 32-BIT VERSION (NOT THE x64)
// of MySQL 5.1 - "Windows MSI Installer"
// Located at http://dev.mysql.com/downloads/mysql/5.1.html#win32
// DO NOT GET THE "WINDOWS ESSENTIALS" PACKAGE
// DO NOT GET __ANY__ x64 crap EVEN IF you are on
// windows 64 bit, ALWAYS use the NORMAL (non-64 bit)
// stuff (see Ancient Dragon's comments for why:
// http://www.programmingforums.org/thread16958.html)
// Done that? GOOD!! Onto step 2.
// 2) ENSURE THAT mysql.h is in your VISUAL STUDIO
// PROJECT PATH SETTINGS. If you don't do this,
// then you'll may an error of the form of:
// Error 1 fatal error C1083: Cannot open include file: 'mysql.h':
// No such file or directory
// For me, mysql.h is in :
// C:\Program Files\MySQL\MySQL Server 5.1\include
// But you have to tell VISUAL STUDIO THAT!! IT doesn't know.
// Need to edit Visual Studio INCLUDE Directory settings. here's how.
// SO I, click
// 1 TOOLS -> OPTIONS
// 2 PROJECTS AND SOLUTIONS -> VC++ DIRECTORIES (left hand panel)
// 3 (now in right hand panel),
// from the two dropdowns there
// (hanging like two microsoft eyes..), uh,
// 4 you just make sure under PLATFORM,
// it says Win32,
// 5 and under SHOW DIRECTORIES FOR,
// it says INCLUDE FILES.
// 6 THEN, click the SHINY YELLOW FOLDER,
// and then click the '...'
// 7 and navigate to your MySQL INSTALL DIR\INCLUDE
// add that folder there.
// For me, I end up with an extra entry in that list that says:
// C:\Program Files\MySQL\MySQL Server 5.1\include
// yours may be slightly different, but not too different,
// hey, don't try and be cool here by being REALLY different please.
//
// OK? So now the #include below should work for you.
// If it doesn't, INSTALL MYSQL FIRST!
// YOU MUST #INCLUDE WINDOWS.H FIRST IF YOU WANT MYSQL
// TO WORK ON WINDOWS!!
#include <windows.h>
#include <stdio.h>
// To get autocomplete to work, you may have to right-click
// your Header Files -> Add Existing Item... and pick
// mysql.h and add it to your project. I've copy and pasted
// the file into this project, though.
// !!
// You may only use the form below if you have followed the
// installation instructions above.
/////#include <mysql.h>
#include "mysql_include/mysql.h" // use this form if you haven't "installed"
// MySQL header files into visual studio as explained above.
// You must also add C:\Program Files\MySQL\MySQL Server 5.1\lib\debug
// to your Visual Studio LIBRARY directory settings (follow steps above again, except
// at step 5, you choose "SHOW DIRECTORIES FOR -> LIBRARY FILES"
// and at step 7, you add C:\Program Files\MySQL\MySQL Server 5.1\lib\debug
// (or whatever yours really is)
// !!
// You may only use the form below if you have followed the
// installation instructions above.
/////#pragma comment( lib, "libmysql.lib" )
#pragma comment( lib, "mysql_lib/debug/libmysql.lib" ) // use this form if you haven't "installed"
// MySQL header files into visual studio as explained above.
// libmysql.lib is what is termed an "import library" - basically
// it is what wires up function calls in this program to MYSQL
// functionality to the libmysql.dll file.
// So what about libmysql.dll?
// FINALLY, ENSURE TO COPY libmysql.dll to EITHER: the \Debug folder
// of this project (WHERE THE FINAL .EXE RESIDES), __OR__, to
// C:\WINDOWS\System32 (if that doesn't work, then copy it to C:\WINDOWS\System).
// For me, libmysql.dll lives in
// C:\Program Files\MySQL\MySQL Server 5.1\lib\debug
// Its also included in the mysql_lib/debug folder of
// this project.
// To quote Charlie Charlie Petzold, Programming windows 5th ed:
// You can put a DLL file:
// A dynamic library must be present on the disk
// when a program is run that uses the library.
// When Windows needs to load a DLL module before running
// a program that requires it, the librar must be stored:
// 1. In the directory containing the .exe program
// 2. the current directory
// 3. the Windows system directory
// 4. the windows directory
// 5. or a directory accessibel through the PATH string in the MS-DOC environment
// The directories are searched in the above order.
#pragma endregion
#pragma region CODING WITH MYSQL
////
// Globals
MYSQL mysql; // the MYSQL global object. Passed to mysql_init,
// and there's only one of this.
MYSQL * conn ; // represents connection to database
//
////
int main()
{
// OK!! Now that you've got all the setup-y stuff out of the way, its
// time to connect to MySQL!!
// here are some great references:
// 1) http://c-programming.suite101.com/article.cfm/using_a_mysql_databases_with_c
// 2) http://dev.mysql.com/doc/refman/5.1/en/windows-client-compiling.html
mysql_init( &mysql ) ;
// PLEASE SEE DOCS PAGE FOR MORE DETAILS
// ABOUT mysql_real_connect():
// http://dev.mysql.com/doc/refman/5.0/en/mysql-real-connect.html
conn = mysql_real_connect( &mysql,
"localhost",// synonymous with 127.0.0.1
"root", // connect as user="root". Uh, bad security here..
"", // my root password is blank. REALLY bad security :)
"mysql", // connect to the 'mysql' _database_ within MySQL itself.
// if you create another database, then you can
// specify you'd like to connect to that one here.
0, // port. Mine is on 3306, but you can leave it as 0
// and it seems to work automatically.
0, // unix_socket (not in use)
0 ) ; // client flag: usually 0, unless you want special features (see docs page)
// At this point you may be wondering, ok,
// so if this is real_connect, what's fake_connect?
// There is a mysql_connect() function! Which is
// basically the "fake" connect... see docs, but
// the "fake" functions (mysql_query(), mysql_connect()),
// are like watered down version of their _real_ counterparts.
// Sometimes useful, sometimes not. Again, see docs pages.
// Check if connection succeeded.
if( conn == NULL )
{
printf("Couldn't connect to MySQL database server!\n");
printf("Error: %s\n", mysql_error( &mysql ) ) ;
return 1 ;
}
else
{
printf("Connect success\n") ;
}
#pragma region running an actual query
// Here, we are connected.
// form a sql string to execute.
char * query = "select * from user" ;
int queryState;
queryState = mysql_query( conn, query ) ;
if( queryState != 0 )
{
printf("Whoops! The query failed. Error: %s\n", mysql_error( conn ) );
return 1 ;
}
// here, query succeeded, so we can proceed
// to pull out results.
MYSQL_RES * resultset ;
MYSQL_ROW row; // MYSQL_ROW is #defined as (char **)
// Data ALWAYS comes back from MySQL as
// an array of strings. To convert it
// to ints or whatever is YOUR JOB as the programmer.
// mysql_store_result basically fetches
// the entire array of results and dumps them
// into our local program memory space (all
// in the resultset variable.
resultset = mysql_store_result( conn );
// How many rows will there be?
int numRows = mysql_num_rows( resultset ) ;
printf( "There are %d ROWS (records) of data\n", numRows ) ;
// Now tell me what columns there are
// in the result set.
int numFields = mysql_num_fields( resultset ) ;
printf( "There are %d FIELDS (columns) of data\n", numFields ) ;
// Print all those column by name
MYSQL_FIELD * fields = mysql_fetch_fields( resultset ) ;
for( int i = 0 ; i < numFields ; i++ )
{
printf( "%25.25s", fields[i].name ) ;
}
printf( "\n" ) ;
// print all results
while( row = mysql_fetch_row( resultset ) )
{
// row is 2d array of char
// underlying type is char **
for ( int i = 0; i < numFields ; i++ )
{
printf( "%25.25s", row[ i ] ) ;
}
// next row
printf( "\n" ) ;
}
#pragma endregion
// Now free the result
mysql_free_result( resultset );
// And close down.
mysql_close( conn ) ;
return 0;
}
#pragma endregion // CODING WITH MYSQL
// Your hands quiver with power.
// You are now a MySQL GURU.
// For the record, there's also:
// Connector C++: http://forge.mysql.com/wiki/Connector_C%2B%2B
// MySQL++: http://tangentsoft.net/mysql++/
// I chose not to use either library because.. well, I dislike
// additional layers.
// TROUBLESHOOTING:
//
// "This application has failed to start because LIBMYSQL.dll
// was not found. Re-installing the application may fix this problem."
// So, like internet superhero says, you have 3 options:
// [ http://blog.ulf-wendel.de/?p=215 ]
// 1. Copy LIBMYSQL.dll into you Windows system directory (C:\Windows\system and/or C:\windows\system32, whichever spins your wheels)
// 2. You copy LIBMYSQL.dll into the current working directory
// 3. You add the location of the LIBMYSQL.dll to your path setting, for example using SET PATH=%PATH%;C:\path\to\LIBMYSQL.dll
// LIBMYSQL.dll is somewhere in your MYSQL INSTALLATION directory..
// so find it, and copy LIBYMSQL.dll to C:\Windows\System32 and/or C:\Windows\System
// OR copy it to the \Debug directory for this project (where the final .exe resides)
// Final note: static lib compiling.
//#pragma comment( lib, "mysqlclient.lib" ) // doesn't work.. produces 76 errors of the form
// Error 1 error LNK2005: __aligned_malloc already defined in MSVCRTD.lib(MSVCR90D.dll) (from file LIBCMTD.lib)
//
// root of problem seems to be in the warning:
// Warning 44 warning LNK4098: defaultlib 'MSVCRTD' conflicts with use of other libs; use /NODEFAULTLIB:library
// Problem docs:
// http://curl.haxx.se/mail/lib-2006-04/0101.html
// http://www.codeguru.com/forum/archive/index.php/t-375084.html
// MikeAThon, at the bottom of the second post there, says
// LIBCMT is the static C-runtime library (and is multi-threaded),
// whereas MSVCRTD is the dynamic linking C-runtime. See
// "How to link with the correct C Run-Time (CRT) library" at
// http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q140584& .
// According to that KB article, "the linker will issue a warning
// (LNK4098) if a resulting module attempts to combine more than
// one copy of the CRT library"
// So go into linker -> input -> ignore all default libraries (/NODEFAULTLIB)
// See Internet Superhero again for more help http://blog.ulf-wendel.de/?p=215
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