チュートリアル： Ultra Light イベント通知の使用

//Just some output formatting.
system(“cls”);
printf(” _____________________________________________ \n”);
printf(“| %10s | %30s |\n”,”cust_id”,”cust_name”);
printf(“|____________|________________________________|\n”);
while(rs->Next())
{
rs->Get(2).GetString(dest,30);
printf(“| %10d | %30s |\n”,(int)rs->Get(1),dest);
}
printf(“|____________|________________________________|\n”);

//Display the time for the last refresh of the data.
GetLocalTime(&lt);
printf(“Last refresh done at: %02d:%02d:%02d\n”,lt.wHour,lt.wMinute,lt.wSecond);

//Clean up.
free(dest);
rs->Release();
}

//test the connection
if(_conn != NULL)
{
//this is it…
_conn->RegisterForEvent(“Commit”,“ULCustomer”,NULL,true);

//Do a first output.
PreparedStatement *stmt = _conn->PrepareStatement(UL_TEXT(“SELECT * from ULCustomer”));
output(stmt->ExecuteQuery());
do
{
//Check for any notifications on the default queue. If the table has been modified, refresh it.
                     //There is only one regiestered event, so there is no need to check for any additional paramteres.
_conn->GetNotification(NULL,100).GetString(ulevent,20);
if(strcmp(“Commit”,ulevent)==0)
{
PreparedStatement *stmt = _conn->PrepareStatement(UL_TEXT(“SELECT * from ULCustomer”));
output(stmt->ExecuteQuery());
}
}
while(flag);
_conn->Release();
}
else
{
printf(“Error opening connection to database with the following connection string: %s\n”,conn_string);
}
free(ulevent);
dbMgr->Shutdown(_sqlca);
_sqlca.Finalize();
return 0;
}

using namespace UltraLite;

static char* const conn_string = “DBF=temp.udb;UID=dba;PWD=sql”;
int flag=1;//flag to signal shutdown of watchthread.

void output(ResultSet *rs)
{
SYSTEMTIME lt;
char *dest = (char*)malloc(sizeof(char)*30);

//Just some output formatting.
system(“cls”);
printf(” _____________________________________________ \n”);
printf(“| %10s | %30s |\n”,”cust_id”,”cust_name”);
printf(“|____________|________________________________|\n”);
while(rs->Next())
{
rs->Get(2).GetString(dest,30);
printf(“| %10d | %30s |\n”,(int)rs->Get(1),dest);
}
printf(“|____________|________________________________|\n”);

//Display the time for the last refresh of the data.
GetLocalTime(&lt);
printf(“Last refresh done at: %02d:%02d:%02d\n”,lt.wHour,lt.wMinute,lt.wSecond);

//Clean up.
free(dest);
rs->Release();
}

DWORD WINAPI db_check(LPVOID lpParam)
{
       char* ulevent = (char*)malloc(sizeof(char)*20);
//init objects and open connection
ULSqlca _sqlca;
_sqlca.Initialize();
DatabaseManager* dbMgr = ULInitDatabaseManager(_sqlca);
Connection* _conn = dbMgr->OpenConnection(_sqlca,conn_string);

//test the connection
if(_conn != NULL)
{
//this is it…
_conn->RegisterForEvent(“Commit”,“ULCustomer”,NULL,true);

//Do a first output.
PreparedStatement *stmt = _conn->PrepareStatement(UL_TEXT(“SELECT * from ULCustomer”));
output(stmt->ExecuteQuery());
do
{
//Check for any notifications on the default queue. If the table has been modified, refresh it.
                     //There is only one regiestered event, so there is no need to check for any additional paramteres.
_conn->GetNotification(NULL,100).GetString(ulevent,20);
if(strcmp(“Commit”,ulevent)==0)
{
PreparedStatement *stmt = _conn->PrepareStatement(UL_TEXT(“SELECT * from ULCustomer”));
output(stmt->ExecuteQuery());
}
}
while(flag);
_conn->Release();
}
else
{
printf(“Error opening connection to database with the following connection string: %s\n”,conn_string);
}
free(ulevent);
dbMgr->Shutdown(_sqlca);
_sqlca.Finalize();
return 0;
}

int main()
{
      DWORD dwThreadID;
      HANDLE watchthread = CreateThread(NULL,0,db_check,NULL,0,&dwThreadID);
     
      getchar();
      flag=0;
      switch(WaitForSingleObject(watchthread,INFINITE))
      {
            case WAIT_OBJECT_0:
            {
                  printf(“All threads ended, cleaning up for application exit…\n”);
                  break;
            }
            default:
            {
                  printf(“Wait error (%d)\n”, GetLastError());
                  break;
            }
      }
      return 0;
}