Use libmysql.dll directly to read query result from MYSQL

GP2X · #1 (**permalink**) 01-13-2007, 07:12 PM

Since mql4 doesn't support point, I didn't find any way to read the result of a select sentence. Maybe someone already created some dlls to do that which I don't know.
Here is my way, use concat_ws to put all the returned columns into one string. Map the returned row structure to a string in mql4. Then scan the string and convert to expected column values.

GP2X · #2 (**permalink**) 01-13-2007, 07:13 PM

PHP Code:


			
//+------------------------------------------------------------------+

//|                                                  mySQLTester.mq4 |

//|                                            Copyright ?2006, GP2X |

//|                                                                  |

//+------------------------------------------------------------------+

#property copyright "Copyright ?2006, GP2X"

#property link      ""

#define DELIM ";"

//#include <mysql.mqh>



#import "libmysql.dll"

int mysql_init(int db);

int mysql_errno(int TMYSQL);

int mysql_real_connect( int TMYSQL,string host,string user,string password, string DB,int port,int socket,int clientflag);

int mysql_real_query(int TMSQL,string query,int length);

void mysql_close(int TMSQL);



int mysql_store_result(int TMSQL);

string mysql_fetch_row(int result);

int mysql_num_rows(int result);

void mysql_free_result(int result);

#import



int mysql;



int mTicket, mType;

string mSymbol;

double mLots, mOpen, mClose, mStopLoss, mTakeProfit;



//+------------------------------------------------------------------+

//| expert initialization function                                   |

//+------------------------------------------------------------------+

int init()

  {

   string row;

   connect();

   string query="Select concat(';',concat_ws(';', ticket, symbol, type, lots, open, close, stoploss, takeprofit)) from trades";

   int length=StringLen(query);

   mysql_real_query(mysql,query,length);

   int result = mysql_store_result(mysql);

   int numOfRows = mysql_num_rows(result);

   for (int i=0;i<numOfRows;i++) {

      row = mysql_fetch_row(result);

      decodeTrade(row);

      Comment("Ticket=", mTicket, ",Symbol=", mSymbol, ",Type=", mType, ",Lots=", mLots, ",Open=", mOpen, ",Close=", mClose, ",SL=", mStopLoss, ",TakeProfit=", mTakeProfit);

   }

   mysql_free_result(result);

   

   return(0);

  }

//+------------------------------------------------------------------+

//| expert deinitialization function                                 |

//+------------------------------------------------------------------+

int deinit()

  {

   mysql_close(mysql);

   return(0);

  }

//+------------------------------------------------------------------+

//| expert start function                                            |

//+------------------------------------------------------------------+

int start()

  {

//----

   

//----

   return(0);

  }

//+------------------------------------------------------------------+



void connect() {



   mysql = mysql_init(mysql);

   if (mysql!=0) Print("allocated");

   string host="localhost";

   string user="GP2X";

   string password="forex";

   string DB="forex";

   int clientflag=0;

   int port=3306;

   string socket="";

   int res=mysql_real_connect(mysql,host,user,password,DB,port,socket,clientflag);

   int err=GetLastError();

   if (res==mysql) Print("connected");

   else Print("error=",mysql," ",mysql_errno(mysql)," ");



}



void decodeTrade(string trade) {

   int begin = StringFind(trade, DELIM)+1;

   int end = StringFind(trade, DELIM, begin);

   mTicket = StrToInteger(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mSymbol = StringSubstr(trade, begin, end-begin);

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mType = StrToInteger(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mLots = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mOpen = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mClose = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mStopLoss = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringLen(trade);

   mTakeProfit = StrToDouble(StringSubstr(trade, begin, end-begin));

}

barnix · #3 (**permalink**) 01-13-2007, 07:44 PM

mysql Delphi MT4 example from a russian forum
http://treide.ru/modules/newbb_plus/...rder=0&start=0

ttauzo · #4 (**permalink**) 09-12-2007, 03:56 PM

Has anyone tried it? I can connect to MySQL but have no idea how to do it with Oracle?

muyuan11 · #5 (**permalink**) 11-23-2008, 07:22 PM

it work fine

Quote:

Originally Posted by GP2X

PHP Code:


			
//+------------------------------------------------------------------+

//|                                                  mySQLTester.mq4 |

//|                                            Copyright ?2006, GP2X |

//|                                                                  |

//+------------------------------------------------------------------+

#property copyright "Copyright ?2006, GP2X"

#property link      ""

#define DELIM ";"

//#include <mysql.mqh>



#import "libmysql.dll"

int mysql_init(int db);

int mysql_errno(int TMYSQL);

int mysql_real_connect( int TMYSQL,string host,string user,string password, string DB,int port,int socket,int clientflag);

int mysql_real_query(int TMSQL,string query,int length);

void mysql_close(int TMSQL);



int mysql_store_result(int TMSQL);

string mysql_fetch_row(int result);

int mysql_num_rows(int result);

void mysql_free_result(int result);

#import



int mysql;



int mTicket, mType;

string mSymbol;

double mLots, mOpen, mClose, mStopLoss, mTakeProfit;



//+------------------------------------------------------------------+

//| expert initialization function                                   |

//+------------------------------------------------------------------+

int init()

  {

   string row;

   connect();

   string query="Select concat(';',concat_ws(';', ticket, symbol, type, lots, open, close, stoploss, takeprofit)) from trades";

   int length=StringLen(query);

   mysql_real_query(mysql,query,length);

   int result = mysql_store_result(mysql);

   int numOfRows = mysql_num_rows(result);

   for (int i=0;i<numOfRows;i++) {

      row = mysql_fetch_row(result);

      decodeTrade(row);

      Comment("Ticket=", mTicket, ",Symbol=", mSymbol, ",Type=", mType, ",Lots=", mLots, ",Open=", mOpen, ",Close=", mClose, ",SL=", mStopLoss, ",TakeProfit=", mTakeProfit);

   }

   mysql_free_result(result);

   

   return(0);

  }

//+------------------------------------------------------------------+

//| expert deinitialization function                                 |

//+------------------------------------------------------------------+

int deinit()

  {

   mysql_close(mysql);

   return(0);

  }

//+------------------------------------------------------------------+

//| expert start function                                            |

//+------------------------------------------------------------------+

int start()

  {

//----

   

//----

   return(0);

  }

//+------------------------------------------------------------------+



void connect() {



   mysql = mysql_init(mysql);

   if (mysql!=0) Print("allocated");

   string host="localhost";

   string user="GP2X";

   string password="forex";

   string DB="forex";

   int clientflag=0;

   int port=3306;

   string socket="";

   int res=mysql_real_connect(mysql,host,user,password,DB,port,socket,clientflag);

   int err=GetLastError();

   if (res==mysql) Print("connected");

   else Print("error=",mysql," ",mysql_errno(mysql)," ");



}



void decodeTrade(string trade) {

   int begin = StringFind(trade, DELIM)+1;

   int end = StringFind(trade, DELIM, begin);

   mTicket = StrToInteger(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mSymbol = StringSubstr(trade, begin, end-begin);

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mType = StrToInteger(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mLots = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mOpen = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mClose = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringFind(trade, DELIM, begin);

   mStopLoss = StrToDouble(StringSubstr(trade, begin, end-begin));

   begin = end+1;

   end = StringLen(trade);

   mTakeProfit = StrToDouble(StringSubstr(trade, begin, end-begin));

}

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
URGENT Query	junglelion	Indicators - Metatrader 4	0	06-03-2007 10:16 PM
Different backtesting result of same EA.	takechance	Metatrader 4	2	10-10-2006 05:00 AM
MT4 to mySQL	witchazel	Questions	2	09-16-2006 01:36 AM
Use another Indicator Result	NoName	Questions	0	04-09-2006 03:35 AM

Register in Forex TSD!
Trading Systems Leaders in this forum (automated trading systems) are winning more than 3000 pips in a month (30000$ investing one lot every time). Click here to register and get more information