I have a program like this
Qt Code: 
  1. QList <S_AIS_DB_SHIP> cAISDataBase::addCurrentShipDataWithFilter(AIS_DB_FILTER filterType, QString searchKey)
  2. //void cAISDataBase::addCurrentShipDataWithFilter(AIS_DB_FILTER filterType,QString searchKey)
  3.  {
  4.     QList<S_AIS_DB_SHIP>aisList;
  5.      QString type;
  6.      if (filterType==ADF_MMSI)
  7.          type=QString("mmsi");
  8.      else if(filterType==ADF_AREAFILTER)
  9.          type=QString("areaFilter");
  10.      else if (filterType==ADF_STATUS)
  11.          type=QString("status");
  12.      else if (filterType==ADF_COG)
  13.          type=QString("cog");
  14.      else if (filterType==ADF_SOG)
  15.          type=QString("sog");
  16.      else if (filterType==ADF_IMO)
  17.          type=QString("imo");
  18.      else if (filterType==ADF_CALLSIGN)
  19.          type=QString("callsign");
  20.      else if (filterType==ADF_STERN)
  21.          type=QString("dim_stern");
  22.      else if (filterType==ADF_BOW)
  23.          type=QString("dim_bow");
  24.      else if (filterType==ADF_STARBOARD)
  25.          type=QString("dim_starboard");
  26.      else if (filterType==ADF_PORT)
  27.          type=QString("dim_port");
  28.      else if (filterType==ADF_WIDTH)
  29.          type=QString("width");
  30.      else if (filterType==ADF_LENGTH)
  31.          type=QString("length");
  32.      else if (filterType==ADF_NAME)
  33.          type=QString("name");
  34.  
  35.      cMYSQLDB *mysqldb=createDbInstance();
  36.      if(mysqldb->open()){
  37.          MYSQL_RES *result;
  38.          MYSQL_ROW row;
  39.          QString query="SELECT *FROM SKM_T_AIS_CURRENTSHIPLIST where" +type+ " ='" +searchKey +";";
  40.  
  41.          result=mysqldb->query(query);
  42.          if (result){
  43.              S_AIS_DB_SHIP dbShip;
  44.              while ((row=mysql_fetch_row(result))!=NULL){
  45.                  S_AIS_DB_STATUSDATA statusDataTemp;
  46.                  statusDataTemp.mmsi = QString(row[0]);
  47.                  statusDataTemp.lat = QString(row[1]).toDouble();
  48.                  statusDataTemp.lon = QString(row[2]).toDouble();
  49.  
  50.                  statusDataTemp.sog = QString(row[3]).toDouble();
  51.                  statusDataTemp.cog = QString(row[4]).toDouble();
  52.                  statusDataTemp.lastUpdate=QString(row[5]);
  53.                  statusDataTemp.status=QString(row[6]);
  54.  
  55.                  S_AIS_DB_SHIPINFO shipInfoDataTemp;
  56.  
  57.                  shipInfoDataTemp.mmsi=QString(row[7]);
  58.                  shipInfoDataTemp.IMO = QString(row[8]);
  59.                  shipInfoDataTemp.callsign=QString(row[9]);
  60.                  shipInfoDataTemp.name = QString(row[10]);
  61.                  shipInfoDataTemp.width=QString(row[11]).toDouble();
  62.                  shipInfoDataTemp.length=QString(row[12]).toDouble();
  63.                  shipInfoDataTemp.dim_port=QString(row[13]).toInt();
  64.                  shipInfoDataTemp.dim_starboard=QString(row[14]).toInt();
  65.                  shipInfoDataTemp.dim_bow=QString(row[15]).toInt();
  66.                  shipInfoDataTemp.dim_stern=QString(row[16]).toInt();
  67.                  aisList.append(dbShip);
  68.              }
  69.          }
  70.          mysqldb->closeRslt(result);
  71.          mysqldb->close();
  72.      }
  73.      delete mysqldb;
  74.   }
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this program to filter tableWidget items

Qt Code: 
  1. void AIS::on_lineEdit_textChanged(QString )
  2. {
  3.     QList<S_AIS_DB_SHIP>aislist;
  4.     aislist=m_db->addCurrentShipDataWithFilter(filterType,searchKey);
  5.     for (int i=0;i<aislist.count();i++){
  6.         int curRow =ui->tableWidget->rowCount();
  7.         ui->tableWidget->insertRow(curRow);
  8.         ui->tableWidget->setItem(curRow,0, new QTableWidgetItem (aislist.at(i).statusData.mmsi));
  9.         ui->tableWidget->setItem(curRow,1, new QTableWidgetItem (aislist.at(i).shipInfo.IMO));
  10.         ui->tableWidget->setItem(curRow,2, new QTableWidgetItem (aislist.at(i).shipInfo.name));
  11.         ui->tableWidget->setItem(curRow,4, new QTableWidgetItem (QString::number(aislist.at(i).statusData.sog)));
  12.         ui->tableWidget->setItem(curRow,5, new QTableWidgetItem (QString::number(aislist.at(i).statusData.cog)));
  13.         ui->tableWidget->setItem(curRow,6, new QTableWidgetItem (QString::number(aislist.at(i).statusData.lat)));
  14.         ui->tableWidget->setItem(curRow,7, new QTableWidgetItem (QString::number(aislist.at(i).statusData.lon)));
  15.     }
  16.     searchKey = ui->lineEdit->text();
  17.  
  18.     if(ui->comboBox->currentText() == "MMSI"){
  19.         filterType = ADF_MMSI;
  20.     }
  21.     else if(ui->comboBox->currentText() == "IMO"){
  22.         filterType = ADF_IMO;
  23.     }
  24.     else if(ui->comboBox->currentText() == "Name"){
  25.         filterType = ADF_NAME;
  26.     }
  27.     m_db->addCurrentShipDataWithFilter(filterType, searchKey);
  28. }
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And this is a function that call the function above

My program exit when I type something in lineEdit...
I don't know what's wrong with my program??
If i try to debug it, it displays that the data is not synchronous...
Is my function not called properly???\
Really need help...