The concept of batch updating with conditions - mORMot (Delphi/Pascal)

.dpr

program Concept_mORMotBatchUpdateWithConditionsPrj;

uses
  System.SysUtils, SynCommons, mORMot, mORMotHttpClient;

{$APPTYPE CONSOLE}

{$R *.res}

type
  TSQLPerson = class(TSQLRecord)
  private
    FName: String;
    FVersionNum: Int64;
  published
    property Name: String read FName write FName;
    property VersionNum: Int64 read FVersionNum write FVersionNum;
  end;

procedure CheckBatchResults(const aBatchUpdateResultArray: TIDDynArray);
begin
end;

const
  cMrJohnsRecordId = 1;
var
  dbCnn: TSQLHttpClient;
  personRec: TSQLPerson;
  batchUpdater: TSQLRestBatch;
  batResults: TIDDynArray;
begin
  // dbCnn := TSQLHttpClient.Create('localhost', 888, ...
  personRec := TSQLPerson.Create;
  batchUpdater := TSQLRestBatch.Create(dbCnn, TSQLPerson, MaxInt);
  dbCnn.Retrieve(cMrJohnsRecordId,  personRec);
  personRec.Name := UpperCase(personRec.Name);

  // As we know we CAN do this:
  batchUpdater.Update(personRec);

  // BUT, how to do this:
  batchUpdater.Update(personRec, ' WHERE VersionNum = ' + IntToStr(personRec.VersionNum));
  // The idea is using a VersionNum field to avoid the update conflict in a multi-client environment.
  // In other words, the update operation should only succeed if the VersionNum has not been changed
  // by other clients.
  // Of course, many SQL engine, including SQLite, supports the 'UPDATE...WHERE' statement:
  // https://www.sqlite.org/lang_update.html

  // Now check if the update was a success by iterating the batResults array values, and take further action
  // accordingly.
  CheckBatchResults(batResults);
end.