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));

}

mudar · #6 (**permalink**) 11-09-2009, 08:05 AM

Dear All, I am using "libmysql.dll" in my EA, on testing mode, this seems to work fine, and in live mode Metatrader crash.
Anyone have any idea how to solve this ?