MySQL Connector/C ++ interface instance

The official mysql website provides instructions and examples for MySQL ctor/C ++ documentation, if the code for specific instances is just a raw plug-in to the project, it will never work. Because of the security requirements of the project, you need to pay close attention to fault tolerance and Resource Creation and release issues, next I will post a method function of my own, which covers related security processing and also involves calling the stored procedure:
 
 

Bool CommonService:... (JSONNode & in, JSONNode & out)
{
/* = Verify json input parameters === */
..........
 
/* ==== Parse json input parameters to get the installation code or id, installation time, hard disk serial number, ip address, mac ==== */
 
..........
 
/* ===== Find the input value of the corresponding record in the database through the installation code ===== */
**********/
// 1. Obtain the database connection
Connection * con = G <ConnectionPool> (). GetConnection ();
If (con = NULL)
{
LOG4CXX_ERROR (g_logger, "cannot get database connection ");
Out. push_back (JSONNode (RESULT, ACTION_FALSE ));
Out. push_back (JSONNode (ERROR_MESSAGE, "cannot get database connection "));
Return false;
}
 
Int ret = 1;
PreparedStatement * prep_stmt = NULL;
ResultSet * res = NULL;
 
Try
{
Con-> setSchema (G <ConnectionPool> (). GetDBName (). c_str ());
 
// Execute SQL to change the installation status
Std: string SQL _statement = "update tb_host set reg_date = ?, Sn = ?, Ip = ?, Mac = ?, State = ?, Sync_state =? Where reg_code =? And state =? "; // SQL statement to be executed
// Transaction Processing
Con-> setAutoCommit (0 );
Prep_stmt = con-> prepareStatement (SQL _statement.c_str ());
 
Prep_stmt-> setString (1, install_time.c_str ());
Prep_stmt-> setString (2, harddrive_sn.c_str ());
Prep_stmt-> setString (3, ip_address.c_str ());
Prep_stmt-> setString (4, mac_address.c_str ());
Prep_stmt-> setInt (5, HAS_INSTALL );
Prep_stmt-> setInt (6, HAS_SYNC );
Prep_stmt-> setString (7, install_code.c_str ());
Prep_stmt-> setInt (8, NO_INSTALL );
 
If (prep_stmt-> executeUpdate () = 0)
{
Ret = 2;
LOG4CXX_INFO (g_logger ,".....");
Out. push_back (JSONNode (ERROR_MESSAGE ,"....."));
Goto Finally_handle;
}
// Call the stored procedure with the Default policy
Std: string procedure = "CALL updateHostPolicyByModHost (?,?, @ Ret, @ msg )";
Prep_stmt = con-> prepareStatement (procedure. c_str ());
Prep_stmt-> setString (1, install_code.c_str ());
Prep_stmt-> setInt (2, 0 );
Prep_stmt-> execute ();
 
Std: string query = "select @ ret AS ret, @ msg AS msg ";
Prep_stmt = con-> prepareStatement (query. c_str ());
Res = prep_stmt-> executeQuery ();
While (res-> next ())
{
If (res-> getInt ("ret ")! = 0)
{
LOG4CXX_ERROR (g_logger, "..." <res-> getString ("msg"). c_str () <res-> getInt ("ret "));
Out. push_back (JSONNode (ERROR_MESSAGE ,"....."));
Goto Finally_handle;
}
}
Con-> commit ();
 
}
Catch (SQLException & e)
{
Try
{
Con-> rollback ();
}
Catch (SQLException & e)
{
Ret = 0;
LOG4CXX_ERROR (g_logger, "database exception" <e. what ());
Goto Finally_handle;
}
 
Ret = 0;
LOG4CXX_ERROR (g_logger, "database exception" <e. what ());
Out. push_back (JSONNode (ERROR_MESSAGE, e. what ()));
Goto Finally_handle;
}
Catch (...)
{
Ret = 0;
LOG4CXX_ERROR (g_logger, "other errors ");
Out. push_back (JSONNode (ERROR_MESSAGE, "other errors "));
Goto Finally_handle;
}

Finally_handle:
DestorySql (res, prep_stmt );
// Release the connection to the connection pool
G <ConnectionPool> (). ReleaseConnection (con );
 
If (ret = 1)
{
Out. push_back (JSONNode (RESULT, ACTION_SUCCESS ));
Return true;
}
Else if (ret = 2)
{
Out. push_back (JSONNode (RESULT, ACTION_FALSE ));
Return true;
}
Else
{
Out. push_back (JSONNode (RESULT, ACTION_FALSE ));
Return false;
}
 
}
 
/*************************************** *********************************/
/* Destroy database record set Resources */
/*************************************** *********************************/
Void CommonService: DestorySql (ResultSet * res, PreparedStatement * prep_stmt)
{
If (res! = NULL)
{
Try
{
Res-> close ();
}
Catch (SQLException & e)
{
LOG4CXX_ERROR (g_logger, "database exception" <e. what ());
}
Delete res;
Res = NULL;
}
If (prep_stmt! = NULL ){
Try
{
Prep_stmt-> close ();
}
Catch (SQLException & e)
{
LOG4CXX_ERROR (g_logger, "database exception" <e. what ());
}
Delete prep_stmt;
Prep_stmt = NULL;
}
}

 
 
This article is from the "Forever Friend" blog