Most of data access components don't have method for sorting in memory records. So the only way for sorting records is add an order by clause to the query and reopen it. These method make this task easier to do.

Here are the methods:
procedure CutOrderByClause(ASQL:TStrings);
var
  aParser:TParser;
  aStream:TMemoryStream;
  tokenPos,orderByClausePos:integer;
begin
  orderByClausePos:=-1;
  aParser:=nil;
  aStream:=TMemoryStream.Create;
  try
    ASQL.SaveToStream(aStream);
    aStream.Position:=0;
    aParser:=TParser.Create(aStream);
//find previous order by clause position
    while aParser.Token<>toEof do
    begin
      tokenPos:=aParser.SourcePos;
      if lowercase(aParser.TokenString)='order' then
      begin
        orderByClausePos:=tokenPos;
        aParser.NextToken;
        if (aParser.Token=toEof)or(lowercase(aParser.TokenString)<>'by') then
          raise Exception.Create('Incorrect order by clause!')
        else
        begin
          aParser.NextToken;
          while aParser.Token<>toEof do
          begin
            if lowercase(aParser.TokenString)='select' then
              raise Exception.Create('Unable to cut order by clause!');
            aParser.NextToken;
          end;
          break;
        end;
      end;
      aParser.NextToken;
    end;
//cut previous order by clause
    if orderByClausePos>=0 then
    begin
      aStream.Size:=orderByClausePos;
      aStream.Position:=0;
      ASQL.LoadFromStream(aStream);
    end;
  finally
    aParser.Free;
    aStream.Free;
  end;
end;

procedure SortSQL(ASQL:TStrings;OrderByClauseArr:array of string);
var
  i,n,u:integer;
  orderByClause:string;
begin
  CutOrderByClause(ASQL);
  if length(orderByClauseArr)>0 then
  begin
//construct new order by clause
    u:=high(orderByClauseArr);
    orderByClause:='order by ';
    n:=length(orderByClause);
    for i:=0 to u do
    begin
      if length(orderByClause)>n then
        orderByClause:=orderByClause+', ';
      orderByClause:=orderByClause+orderByClauseArr[i];
    end;
//append new order by clause into SQL
    if length(orderByClause)>n then
      ASQL.Append(orderByClause);
  end;
end;

This event handler shows you how to use them:
procedure TfrmSortSQL.btnChangeSQLClick(Sender: TObject);
var
  orderByClauseArr:array of string;
  i,u:integer;
begin
  u:=memSortFields.Lines.Count;
  SetLength(orderByClauseArr,u);
  dec(u);
  for i:=0 to u do
    orderByClauseArr[i]:=memSortFields.Lines[i];
  if u>=0 then
    SortSQL(memSQL.Lines,orderByClauseArr)
  else
    CutOrderByClause(memSQL.Lines);
end;

Or you can simply use it like below:
  SortSQL(memSQL.Lines,['deptno desc','empno','1',inttostr(aField.FieldNo)]);

OK that's all. I hope this article can help your database project development.