Database

Get the table version

Select a random datarecord procedure TForm1.FormCreate(Sender: TObject); begin Randomize; end; procedure TForm1.Button1Click(Sender: TObject); begin Table1.First; Table1.MoveBy(Random(Table1.RecordCount)); end;

Add a password to a paradox table uses Bde, SysUtils, dbtables, windows; function StrToOem(const AnsiStr: string): string; begin SetLength(Result, Length(AnsiStr)); if Length(Result) 0 then CharToOem(PChar(AnsiStr), PChar(Result)); end; function TablePasswort(var Table: TTable; password: string): Boolean; var […]

BDE Error list: $0000 (0) = Successful completion. $0021 (33) = System Error $0022 (34) = Object of Interest Not Found $0023 (35) = Physical Data Corruption $0024 (36) = I/O Related Error $0025 (37) […]

Show a TTable’s deleted records procedure DeletedRecords(Table: TTable; SioNo: Boolean); begin Table.DisableControls; try Check(DbiSetProp(hDBIObj(Table.Handle), curSOFTDELETEON, Longint(SioNo))); finally Table.EnableControls; end; Table.Refresh; end;

Open a password-saved paradox database without knowing the password If you forget your paradox table password, try out on of these passwords, it works well. for PARADOX 7.0 use this password: “jIGGAe” or “cupcdvum” for […]

Undelete a dBASE record procedure RecordUndelete(aTable: TTable); begin aTable.UpdateCursorPos; try Check(DbiUndeleteRecord(aTable.Handle)); except ShowMessage(‘No undelete performed.’); end; end;

Save a Formula One spreadsheet to a blob field uses vcf1, dbtables; procedure SaveSpreadsheet(F1Book: TF1Book); var BlobStream: TBlobStream; MyBlob: HGlobal; pblob: Pointer; begin with Datamodule1.Query1 do begin Set8087CW($133f); try Application.ProcessMessages; F1Book.SaveWindowInfo; MyBlob := GlobalAlloc(GMEM_MOVEABLE, 2000); […]

Remove a dbase index flag function UnCheckIndex(FileDbf: string): Boolean; var Dbf: file; Car: Char; begin Result := T; AssignFile(Dbf, FileDbf); Car := #0; {$I-} Reset(Dbf, 1); if not ErrorIO(FileDbf, IoResult) then begin Seek(Dbf, 28); {Flag’s […]

Pack a Table Packs a Paradox table by calling the BDE DbiDoRestructure function. The TTable passed as the first parameter must be closed. The TDatabase passed as the second parameter must be connected. function dgPackParadoxTable(Tbl: […]

Select all Fields in a DBGrid function GridSelectAll(Grid: TDBGrid): Longint; begin Result := 0; Grid.SelectedRows.Clear; with Grid.DataSource.DataSet do begin First; DisableControls; try while not EOF do begin Grid.SelectedRows.CurrentRowSelected := True; Inc(Result); Next; end; finally EnableControls; […]

Extract the ODBC System Data Sources uses Registry; procedure TForm1.Button1Click(Sender: TObject); var n: Integer; List: TStringList; Reg: TRegistry; begin Reg := TRegistry.Create; try Reg.RootKey := HKEY_CURRENT_USER; Reg.LazyWrite := False; Reg.OpenKey(‘Software\ODBC\ODBC.INI\ODBC Data Sources’, False); List := […]

Accelerate database searches type TForm1 = class(TForm) DataSource1: TDataSource; Table1: TTable; Button1: TButton; end; procedure TForm1.Button1Click(Sender: TObject); var SeekValue: string; begin Table1.DisableControls; Table1.FindKey([SeekValue]); Table1.EnableControls; end;

Check if the Borland Database Engine (BDE) is installed uses BDE; function CheckBDEInstalled: Boolean; begin Result := (dbiInit(nil) = DBIERR_NONE) end; procedure TForm1.Button1Click(Sender: TObject); begin if CheckBDEInstalled then ShowMessage(‘BDE is installed.’) else ShowMessage(‘BDE is not […]

Make an ADODB Connection using OLE-Automation uses ComObj; function OpenConnection(ConnectionString: AnsiString): Integer; var ADODBConnection: OleVariant; begin ADODBConnection := CreateOleObject(‘ADODB.Connection’); ADODBConnection.CursorLocation := 3; // User client ADODBConnection.ConnectionString := ConnectionString; Result := 0; try ADODBConnection.Open; except Result […]

With different versions of MDAC available it is sometimes useful to know that your application won’t fail because a user hasn’t got the latest version installed. The following function returns the ADO version installed, you […]

{ Loading millions of records into a stringlist can be very slow } procedure TForm1.SlowLoadingIntoStringList(StringList: TStringList); begin StringList.Clear; with SourceTable do begin Open; DisableControls; try while not EOF do begin StringList.Add(FieldByName(‘OriginalData’).AsString); Next; end; finally EnableControls; […]

Move Columns in a TDBGrid type THackAccess = class(TCustomGrid); { THackAccess Is needed because TCustomGrid.MoveColumn is protected and you can’t access it directly. } // In the implementation-Section: procedure MoveDBGridColumns(DBGrid: TDBGrid; FromColumn, ToColumn: Integer); begin […]

(* If you use a database (tables) on a shared network, you can enhance efficiency by setting a number of properties of the TSession component. The TSession component manages a database session. First of all, […]

{ If a database or a table is local on a PC installed (Paradox or Dbase) and the BDE-setting “LOCAL SHARE” is FALSE, then changings are not stored immediatly but are kept in the memory. […]

{Unit to export a dataset to XML} unit DS2XML; interface uses Classes, DB; procedure DatasetToXML(Dataset: TDataSet; FileName: string); implementation uses SysUtils; var SourceBuffer: PChar; procedure WriteString(Stream: TFileStream; s: string); begin StrPCopy(SourceBuffer, s); Stream.Write(SourceBuffer[0], StrLen(SourceBuffer)); end; […]

Sometimes you want to communicate with mySQL or other databases using the unix timestamp. To solve this difference you may want to convert your TDateTime to the unix timestamp format and vice versa. unit unix_utils; […]

// Read an MS-ACCESS Database (any versions) using ADO // Verify if it is an ACCESS MDB // Components Needed on the Application Form are: // TADOtable,TDataSource,TOpenDialog,TDBGrid,TBitBtn. // Date : 14/01/2002 // Author: Michael Casse. […]

As we know, Paradox Tables consist in a table file and some corresponding index files there are many way to copy them: 1. Using TBatchMover (at DataAccess Pallete) with Mode : BatCopy But you can’t […]

Read an MS-ACCESS Database using ADO Verify if it is an ACCESS MDB File Write a Record to MS-ACCESS Database Components Needed on the Application Form are:- TADOtable,TDataSource,TOpenDialog,TDBGrid, TBitBtn,TTimer,TEditTextBox program ADOdemo; uses Forms, uMain in […]

Get the ODBC datasource names uses Registry; procedure TForm1.GetDataSourceNames(System: Boolean); var reg: TRegistry; begin ListBox1.Items.Clear; reg := TRegistry.Create; try if System then reg.RootKey := HKEY_LOCAL_MACHINE else reg.RootKey := HKEY_CURRENT_USER; if reg.OpenKey(‘\Software\ODBC\ODBC.INI\ODBC Data Sources’, False) then […]

procedure TForm1.Button1Click(Sender: TObject); begin Table.Close; Table.Exclusive := True; Table.Open; DbiRegenIndexes(Table.Handle); Table.Close; end;

The normal way for Delphi and Kylix is just to check dbExpress, put a TSQLConnection on a form then double-click the TSQLConnection to display the Connection Editor and set parameter values (database path, connection name […]

If you develop a database related software, then a very popular task is to save some files (documents/images/reports/etc) in some BLOB field of table and use these saved data later. In this tip I want […]

Here’s a demo to demonstrate how to get info about aliases in Delphi. First, create a new project with a listbox and 3 labels (called ListBox1, Label1, Label2, and Label3). Then add an OnCreate event […]

Here is a sample how to quickly create a Paradox table with some field definied using a SQL language to do so procedure TForm1.Button1Click(Sender: TObject); begin with Query1 do begin DatabaseName := ‘DBDemos’; with SQL […]

Lets say that we wish to create a fallawing number (Autoincrese) of an item, without using the AutoIncrese filed. This is usfull when for example there is more users from the same IP that log […]

Change the TDBNavigator images   procedure ChangeDBNavImage(DBnav: TDbNavigator); var i: Integer; tempGlyph: TBitmap; ExePath: string; begin ExePath := ExtractFilePath(Application.ExeName); tempGlyph := TBitmap.Create; try with DBNav do begin for i := 0 to ControlCount – 1 […]