Zeoslib Portal

Code: Select all

  Query.Close;  // <-- this has driven me nuts
  Query.SQL.Text :=
    'SELECT id, sourceid, topicid, ... FROM foo WHERE sourceid = :asourceid ORDER BY id ASC;';
  Query.ParamByName('asourceid').AsInteger := FCurrentSource;
  Query.Open;

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procedure TZSQLStrings.Changing;
begin
  If Assigned(FDataSet) And (FDataSet As TZAbstractRODataset).Active Then
    Raise EZSQLException.Create(SResultsetIsAlreadyOpened);

  inherited;
end;

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 ZConnection1.Connect;
 ZQuery1.SQL.Text := 'SELECT 1';
 ZQuery1.Open;

 ZQuery1.SQL.Text := 'SELECT 2'; // Triggers exception
 ZQuery1.SQL.Strings[0] := 'aaa'; // Triggers exception
 ZQuery1.SQL.Clear; // Triggers exception

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procedure TZQueryHelper.SelectSQL(const SqlQuery: String; const Parameters: TVariantDynArray);
var
  x: Integer;
begin
  Close;
  SQL.Text := SqlQuery;
  for x := Low(Parameters) to High(Parameters) do begin
    ParamByName('P' + IntToStr(x)).Value := Parameters[x];
  end;
  Open;
end;

procedure TZQueryHelper.ExecuteSQL(const SqlQuery: String; const Parameters: TVariantDynArray);
var
  x: Integer;
begin
  Close;
  SQL.Text := SqlQuery;
  for x := Low(Parameters) to High(Parameters) do begin
    ParamByName('P' + IntToStr(x)).Value := Parameters[x];
  end;
  ExecSQL;
end;

function TZQueryHelper.GetSingletonSelect(const SqlQuery: String; const Paramaters: TVariantDynArray): Variant;
begin
  SelectSQL(SqlQuery, Paramaters);
  try
    if RecordCount <> 1 then begin
      raise Exception.Create('GetSingletonSelect expects a result of exactly one record. ' + IntToStr(RecordCount) + ' records were returned.');
    end else begin
      if FieldCount <> 1 then begin
        raise Exception.Create('GetSingletonSelect expects a result record with exactly one field. ' + IntToStr(RecordCount) + ' fields were returned.')
      end else begin
        Result := Fields[0].Value;
      end;
    end;
  finally
    Close;
  end;
end;

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var
  SomeSetting: String;
begin
  // some code
  SomeSetting := VarToString(TempQuery.GetSingletonSelect('select value from attributes where attribute = :P0', ['SomeSetting']));
  // more code
end;