为lazarus TDataSet增加类似TClientDataSet的Delta功能

为lazarus TDataSet增加类似TClientDataSet的Delta功能

适用于所有TDataSet
只需在unit的uses添加DataSetDelta。
BufDataset1.ActivateMonitoring(true)//启动Delta功能
BufDataset1.GetActionSQL('test');//根据Delta生成SQL
继续开源：
https://github.com/szlbz/DataSetDelta.git

unit DataSetDelta;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, BufDataset, DB, TypInfo,Variants;

type

  TDataStateValue = (dsvOriginal, dsvDeleted, dsvInserted, dsvUpdated);

  TDataSetChangesHelper =class Helper for TDataset
  public
    procedure createTable;
    function GetNewDataSet : TBufDataSet;
    function GetOldDataSet : TBufDataSet;
    function GetActionSQL(const ATableName : String; const AKeyFields: String = ''): String;
    function GetChangedCount:int64;
    procedure BeforeInserts(DataSet: TDataSet);
    procedure BeforeEdits(DataSet: TDataSet);
    procedure BeforeDeletes(DataSet:TDataSet);
    procedure AfterPosts(DataSet: TDataSet);
    procedure ActivateMonitoring(Value:Boolean);
    property ChangedCount:int64 read GetChangedCount;
  end;

implementation

procedure TForm1.Button2Click(Sender: TObject);
var sql:string;
begin
  sql:=BufDataset1.GetActionSQL('test');
  if sql<>'' then
    memo1.Lines.Add(sql);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  memo1.Lines.Clear;
  BufDataset1.ActivateMonitoring(true);
end;