The problem of interaction of MQL with databases is not new, however it's still relevant. Use of databases can greatly enhance the possibilities of MetaTrader: storage and analysis of the price history, copying trades from one trading platform to another, providing quotes/trades in real time, heavy analytical computations on the server side and/or using a schedule, monitoring and remote control of accounts using web technologies. See article "How to Access MySQL Databases from MQL5 (MQL4)"". The MQLMySQL library is a solution for accessing MySQL database from MQL4/MQL5 side. If you:

• work with MetaTrader 4 (32-bit) you can use this "MQL4" package (TRM included)
• work with MetaTrader 5 (64-bit) and love "old school" development, you can use this "MQL5 old school" package where simply set of functions implemented (TRM included)
• work with MetaTrader 5 (64-bit) and love "CLASSic" development, you can use this "MQL5 classes" package where implemented classes to work with database (TRM included)
• very improved developer and want to extend library functionality by yourself - you would need:
  • MS Visual Studio 2017 project MQLMySQL to compile MQLMySQL.DLL for x86 and x64 platforms, also this project depends on MySQL headers you can find below
  • MySQL-5.7.28 x32 - MySQL v5.7.28 header files to compile DLL for x86 platforms
  • MySQL-8.0.18 x64 - MySQL v8.0.18 header files to compile DLL for x64 platforms
• appreciate work I've done and want to support me with this and other related projects - I accept PayPal donation

This solution is developed to be free (c) Eugene Lugovoy

• Concurrently open connections - up to 32
• Concurrently open cursors - up to 256
• Length of SQL query - up to 64Kb
• Length of string field value - up to 32Kb
• Support x86 and x64 platforms
• Support UTF-8 string conversion
• Support DML/DDL/DCL command execution
• Support cursors for SELECT commands to retreive data from database

The structure of "MQL4", "MQL5 old school" and "MQL5 classes" directories are similar to MetaTrader terminal's directory structure, so you just need to:

• Setup your MySQL/MariaDB database
• Make sure you can connect to database by using standard tools (like HeidiSQL or so)
• Download sources you need and copy them into MetaTrader Data Folder Note: If you have UAC disabled on your OS, the Data Folder could be similar to Terminal Folder. But if UAC is enabled - you can open Data Folder from terminal by pressing Ctrl+Shift+D or from main menu File->Open Data Folder
• Open Scripts\MyConnection.ini and edit database credentials to connect to your database
• Run MetaTrader terminal and try to run scripts MySQL-XXX on any chart.

When all tests are done successful, you can build your own functionality.

The article "How to Access MySQL Databases from MQL5 (MQL4)" - https://www.mql5.com/en/articles/932

Discussion forum can help to solve your difficulties - https://www.mql5.com/en/forum/37085

My Profile at MQL5 Community - https://www.mql5.com/en/users/elugovoy

To support over PayPal - paypal.me/elugovoy