Быстрый поиск в базах данных

unit Finder;

interface

uses DB, DBTables, SysUtils;

function GrabMemoFieldAsPChar(TheField: TMemoField): PChar;
function DoFindIn(TheField: TField; SFor: string): Boolean;
function FindIt(TheTable: TDataSet; TheFields: array of integer;

  SearchBackward: Boolean; FromBeginning: Boolean; SFor: string): Boolean;
{применение функции FindIt -

if FindIt(NotesSearchT,
[NotesSearchT.FieldByName('Leadman').Index],
False, True, SearchText.Text) then DoSomething; }

implementation

function GrabMemoFieldAsPChar(TheField: TMemoField): PChar;
begin
  with TBlobStream.Create(TheField, bmRead) do

  begin
    GetMem(Result, Size + 1);
    FillChar(Result^, Size + 1, #0);
    Read(Result^, Size);
    Free;
  end;
end;

function DoFindIn(TheField: TField; SFor: string): Boolean;
var

  PChForMemo: PChar;
begin
  Result := False;
  case TheField.DataType of

    ftString:
      begin
        if (Pos(SFor, UpperCase(TheField.AsString)) > 0) then
          Result := True;
      end;
    ftInteger:
      begin
        if (Pos(SFor, TheField.AsString) > 0) then
          Result := True;
      end;
    ftBoolean:
      begin
        if SFor = UpperCase(TheField.AsString) then
          Result := True;
      end;
    ftFloat:
      begin
        if (Pos(SFor, TheField.AsString) > 0) then
          Result := True;
      end;
    ftCurrency:
      begin
        if (Pos(SFor, TheField.AsString) > 0) then
          Result := True;
      end;
    ftDate..ftDateTime:
      begin
        if (Pos(SFor, TheField.AsString) > 0) then
          Result := True;
      end;
    ftMemo:
      begin
        SFor[Ord(SFor[0]) + 1] := #0;
        PChForMemo := GrabMemoFieldAsPChar(TMemoField(TheField));
        StrUpper(PChForMemo);
        if not (StrPos(PChForMemo, @SFor[1]) = nil) then
          Result :=
            True;
        FreeMem(PChForMemo, StrLen(PChForMemo + 1));
      end;
  end;
end;

function FindIt(TheTable: TDataSet; TheFields: array of integer;

  SearchBackward: Boolean; FromBeginning: Boolean; SFor: string): Boolean;
var

  i, HighTheFields, LowTheFields: integer;
  BM: TBookmark;
begin
  TheTable.DisableControls;
  BM := TheTable.GetBookmark;
  try
    LowTheFields := Low(TheFields);
    HighTheFields := High(TheFields);
    SFor := UpperCase(SFor);
    Result := False;
    if FromBeginning then
      TheTable.First;
    if SearchBackward then

    begin
      TheTable.Prior;
      while not TheTable.BOF do
      begin
        for i := LowTheFields to HighTheFields do
        begin
          if DoFindIn(TheTable.Fields[TheFields[i]], SFor) then
          begin
            Result := True;
            Break;
          end;
        end;
        if Result then
          Break
        else
          TheTable.Prior;
      end;
    end
    else
    begin
      TheTable.Next;
      while not TheTable.EOF do
      begin
        for i := LowTheFields to HighTheFields do
        begin
          if DoFindIn(TheTable.Fields[TheFields[i]], SFor) then
          begin
            Result := True;
            Break;
          end;
        end;
        if Result then
          Break
        else
          TheTable.Next;
      end;
    end;
  finally
    TheTable.EnableControls;
    if not Result then

      TheTable.GotoBookmark(BM);
    TheTable.FreeBookmark(BM);
  end;

end;

end.