Example

The following are some snippets from the mql(1) program. They are placed under the MIT license as given at the beginning of the file src/mql.cpp in the Emdros sourcecode package.

#include <emdfdb.h>
#include <emdros_environment.h>
#include <iostream>
#include <sstream>
#include <fstream>
#include <string>


// Not showing exec_file() function

int exec_cin(EmdrosEnv *pEE)
{
  bool bResult;
  std::string strError;
  int nResult;
  if (!pEE->executeStream(std::cin, bResult, true, true)) {
    std::cerr << "FAILURE: Database error executing stdin." << std::endl;
    nResult = 5;
  } else {
    if (!bResult) {
      // std::cerr << "FAILURE: Compiler error executing stdin." << std::endl;
      nResult = 6;
    } else { 
      // std::cout << "SUCCESS executing stdin." << std::endl;
      nResult = 7;
    }
  }

  // Return result
  return nResult;
}

int main(int argc, char* argv[])
{
  // Set defaults
  eOutputKind output_kind = kOKConsole;
  std::string initial_db("emdf");
  std::string filename;
  std::string hostname("localhost");
  std::string user("emdf");
  eBackendKind backend_kind = kSQLite2; // Could also be kPostgreSQL or kMySQL or kSQLite3

  // Get default password
  std::string password;
#if USE[PREUNDERSCORE}DEFAULT_PASSWORD
  getDefaultPassword(password);
#else
  password = "";
#endif

  // Parse arguments
  if (!parse_arguments(argc, argv, output_kind, 
                        initial_db, filename, 
                        hostname, user, password)) {
    print_usage(std::cerr);
    return 1;
  }

  // Make connection
  EmdrosEnv *pEE = new EmdrosEnv(output_kind, kCSISO_8859_1,
				   hostname,
				   user, password,
				   initial_db,
				   backend_kind);
  // Zero-fill password
  zeroFillString(password);

  // Check that we connected
  if (!pEE->connectionOk()) {
    std::cerr << "Connection to backend server could not be established.  Aborting." 
             << std::endl;
    delete pEE;
    return 2;
  }

  int nResult = 3;
  try {
    if (filename == "") {
      nResult = exec_cin(pEE);
    } else {
      nResult = exec_file(pEE, filename);
    }
  } catch (EMdFDBException e) {
    std::cerr << "ERROR: EMdFDBException (Database error)..." << std::endl;
    std::cerr << pEE->getDBError() << std::endl; 
    std::cerr << pEE->getCompilerError() << std::endl;
  } catch (BadMonadsException e) {
    std::cerr << "BadMonadsException caught.  Program aborted." << std::endl;
  } catch (WrongCharacterSetException e) {
    std::cerr << "WrongCharacterSetException caught.  Program aborted." << std::endl;
  } catch (EMdFOutputException e) {
    std::cerr << "EMdFOutputException caught.  Program aborted." << std::endl;
  } catch (...) {
    std::cerr << "Unknown exception occurred.  Program aborted." << std::endl;
  }

  // Clean up
  delete pEE;
  return nResult;
}