RAD Studio VCL Reference
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Indicates whether the underlying database table exists.
property Exists: Boolean;
__property Boolean Exists;
Read Exists at runtime to determine whether a database table exists. If the table does not exist, create a table from the field definitions and index definitions using the CreateTable method.
This property is read-only.
Delphi Examples:
{ The following example shows how to create a table. } procedure TForm1.Button1Click(Sender: TObject); begin Table1.Close; Table1.DeleteTable; end; procedure TForm1.FormCreate(Sender: TObject); var i: Integer; begin Table1:= TTable.Create(Form1); with Table1 do begin DatabaseName := 'DBDEMOS'; TableType := ttParadox; TableName := 'CustInfo'; Table1.Active := False; { Don't overwrite an existing table } if Table1.Exists then MessageDlg('CustInfo table already exists.', mtWarning, [mbOK], 0) else begin { The Table component must not be active } { First, describe the type of table and give } { it a name } { Next, describe the fields in the table } with FieldDefs do begin Clear; with AddFieldDef do begin Name := 'Field1'; DataType := ftInteger; Required := True; end; with AddFieldDef do begin Name := 'Field2'; DataType := ftString; Size := 30; end; end; { Next, describe any indexes } with IndexDefs do begin Clear; { The 1st index has no name because it is { a Paradox primary key } with AddIndexDef do begin Name := ''; Fields := 'Field1'; Options := [ixPrimary]; end; with AddIndexDef do begin Name := 'Fld2Indx'; Fields := 'Field2'; Options := [ixCaseInsensitive]; end; end; { Call the CreateTable method to create the table } CreateTable; Table1.Active:= True; for i := 1 to 20 do Table1.AppendRecord([i*111, i*222]); end; end; DS2.DataSet:= Table1; DBGrid2.DataSource.DataSet:= Table1; Table1.Active:= True; end;
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