MysqlInterface Class Reference

#include <MysqlInterface.h>

Inheritance diagram for MysqlInterface:

Public Member Functions
	MysqlInterface ()
	~MysqlInterface ()
int	connect ()
int	select_db (std::string dbname)
int	query (std::string dbname, std::string query)
int	query (std::string dbname, std::string query, DatabaseRecordVector &records)
int	disconnect ()
Public Member Functions inherited from DbInterface
	DbInterface ()
virtual	~DbInterface ()
bool	is_connected ()
void	set_host (std::string host)
void	set_user (std::string user)
void	set_passwd (std::string passwd)
void	set_dbpath (std::string path)
void	set_port (int port)
void	set_reuse_connection (bool flag)

Protected Member Functions
int	connect (std::string host, std::string user, std::string passwd, int port)

Additional Inherited Members
Protected Attributes inherited from DbInterface
bool	m_isConnected
bool	m_reuseConnection
std::string	m_dbName
std::string	m_dbHost
int	m_dbPort
std::string	m_dbUser
std::string	m_dbPasswd
std::string	m_dbPath

Detailed Description

Definition at line 7 of file MysqlInterface.h.

Constructor & Destructor Documentation

MysqlInterface()

MysqlInterface::MysqlInterface

(

)

Definition at line 10 of file MysqlInterface.cxx.

{}

~MysqlInterface()

MysqlInterface::~MysqlInterface

(

)

Definition at line 12 of file MysqlInterface.cxx.

{}

Member Function Documentation

connect() [1/2]

int MysqlInterface::connect ( )

virtual

Implements DbInterface.

Definition at line 14 of file MysqlInterface.cxx.

                            {
  if ( m_reuseConnection ) connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
  return 0;
}

Referenced by connect(), query(), query(), and select_db().

connect() [2/2]

int MysqlInterface::connect ( std::string host, std::string user, std::string passwd, int port )

protected

Definition at line 19 of file MysqlInterface.cxx.

                                        {
  try
  {
    m_conn = new MYSQL;
    mysql_init( m_conn );
    MYSQL* ret      = 0;
    int    iattempt = 0;
    for ( iattempt = 0; iattempt < 3; iattempt++ )
    {
      ret = mysql_real_connect( m_conn, host.c_str(), user.c_str(), passwd.c_str(),
                                m_dbName.c_str(), port, NULL, 0 );
      if ( ret != 0 )
      { // Everything is fine.  Put out an info message
        std::cout << "DatabaseSvc: Connected to MySQL database" << std::endl;
        break;
      }
      else
      {
        std::cout << "Couldn't connect to MySQL database. Trying again." << std::endl;
        sleep( 1 );
      }
    }
 
    if ( ret == 0 && iattempt == 2 ) throw (char*)mysql_error( m_conn );
 
  } catch ( std::exception& e )
  {
 
    cerr << "Error in MySQL session initialization!" << endl;
    cerr << "*** std::exception caught:" << endl;
    cerr << "***  error message:" << e.what() << endl;
    return -1;
 
  } catch ( ... )
  { return -1; }
 
  m_isConnected = true;
  return 0;
}

disconnect()

int MysqlInterface::disconnect ( )

virtual

Implements DbInterface.

Definition at line 220 of file MysqlInterface.cxx.

                               {
  if ( m_conn )
  {
    mysql_close( m_conn );
    delete m_conn;
    m_conn = NULL;
  }
  m_isConnected = false;
  return 0;
}

Referenced by query(), query(), and select_db().

query() [1/2]

int MysqlInterface::query ( std::string dbname, std::string query )

virtual

Implements DbInterface.

Definition at line 74 of file MysqlInterface.cxx.

                                                           {
  if ( !m_reuseConnection ) connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
 
  try
  {
    // check database name
    if ( m_dbName != dbname )
    {
      m_dbName = dbname;
      select_db( m_dbName );
    }
 
    int status = mysql_real_query( m_conn, sql.c_str(), sql.length() );
    if ( status )
    {
      //        if(mysql_errno(m_conn)==2006){
      //  std::cerr << "MySQL error 2006: MySQL server has gone away"<< std::endl;
      std::cerr << "MySQL error: MySQL server has gone away" << std::endl;
      disconnect();
      // Try to re-connect
      sleep( 5 );
      int ret = connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
      if ( ret == 0 )
      {
        std::cout << "Connected to MySQL database " << std::endl;
        select_db( m_dbName );
        status = mysql_real_query( m_conn, sql.c_str(), sql.length() );
      }
      //  }
 
      if ( status )
      {
        cerr << "Query " << sql << " failed: " << mysql_error( m_conn ) << endl;
        return -1;
      }
    }
  } catch ( ... )
  {
    cerr << "Could not execute query: " << mysql_error( m_conn ) << endl;
    return -1;
  }
 
  if ( !m_reuseConnection ) disconnect();
 
  return 0;
}

query() [2/2]

int MysqlInterface::query ( std::string dbname, std::string query, DatabaseRecordVector & records )

virtual

Implements DbInterface.

Definition at line 121 of file MysqlInterface.cxx.

                                                           {
  if ( !m_reuseConnection ) connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
 
  records.clear();
 
  try
  {
    // check database name
    if ( m_dbName != dbname )
    {
      m_dbName = dbname;
      select_db( m_dbName );
    }
 
    int status = mysql_real_query( m_conn, sql.c_str(), sql.length() );
    if ( status )
    {
      //    if(mysql_errno(m_conn)==2006){
      //         std::cerr << "MySQL error 2006: MySQL server has gone away"<< std::endl;
      std::cerr << "MySQL error: MySQL server has gone away" << std::endl;
      disconnect();
      // Try to re-connect
      sleep( 5 );
      int ret = connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
      if ( ret == 0 )
      {
        std::cout << "Connected to MySQL database " << std::endl;
        select_db( m_dbName );
        status = mysql_real_query( m_conn, sql.c_str(), sql.length() );
      }
      // }
 
      if ( status )
      {
        cerr << "Query " << sql << " failed: " << mysql_error( m_conn ) << endl;
        return -1;
      }
    }
 
    MYSQL_RES* result = mysql_store_result( m_conn );
 
    if ( result )
    {
      int num_fields = mysql_num_fields( result );
 
      if ( num_fields > 0 )
      {
        MYSQL_FIELD* fields;
        fields = mysql_fetch_fields( result );
 
        MYSQL_ROW row;
        while ( ( row = mysql_fetch_row( result ) ) )
        {
          unsigned long* lengths;
          lengths               = mysql_fetch_lengths( result );
          DatabaseRecord* dbrec = new DatabaseRecord;
          int             field;
          for ( field = 0; field < num_fields; field++ )
          {
            if ( row[field] != 0 )
            {
              unsigned long field_len = lengths[field];
              char*         new_record;
              if ( fields[field].type == FIELD_TYPE_BLOB )
              {
                new_record = new char[field_len];
                memcpy( new_record, row[field], field_len );
              }
              else // strings
              {
                new_record = new char[field_len + 1];
                strcpy( new_record, row[field] );
              }
 
              ( *dbrec )[fields[field].name] = new_record;
            }
            else { ( *dbrec )[fields[field].name] = nullptr; }
          }
          records.push_back( dbrec );
        }
      }
      mysql_free_result( result );
      if ( !m_reuseConnection ) disconnect();
 
      return records.size();
    }
  } catch ( ... )
  {
    cerr << "Could not execute query: " << mysql_error( m_conn ) << endl;
    if ( !m_reuseConnection ) disconnect();
    return -1;
  }
 
  if ( !m_reuseConnection ) disconnect();
 
  return 0;
}

select_db()

int MysqlInterface::select_db ( std::string dbname )

virtual

Implements DbInterface.

Definition at line 60 of file MysqlInterface.cxx.

                                                {
  int ret = mysql_select_db( m_conn, dbname.c_str() );
  if ( ret != 0 )
  {
    disconnect();
    // Try to re-connect
    sleep( 5 );
    ret = connect( m_dbHost, m_dbUser, m_dbPasswd, m_dbPort );
    if ( ret == 0 ) { ret = mysql_select_db( m_conn, dbname.c_str() ); }
    if ( ret != 0 ) { throw std::exception(); }
  }
  return 0;
}

Referenced by query(), and query().

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The documentation for this class was generated from the following files:

• MysqlInterface.h
• MysqlInterface.cxx