parameters wrapper for both method callbacks and interface-based services:
      now aParams.Context.ID is to be used insted of aParams.ID 
    - added TJSONObjectDecoder record/object helper for JSON object decoding
      (used e.g. by GetJSONObjectAsSQL() function, and for SQlite3DB process)
    - removed TSQLRecordExternal class type, to allow any TSQLRecord (e.g.
      TSQLRecordMany) to be used with VirtualTableExternalRegister() - there was
      indeed no implementation requirement to force a specific class type

    - now JSON parser will handle #1..' ' chars as whitespace (not only ' ')
    - now huge service JSON response is truncated (to default 20 KB) in logs


  String usage in the Synopse SQLite3 database framework:
    - RawUTF8 is used for every internal data usage, since both SQLite3 and
      JSON do expect UTF-8 encoding
................................................................................
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
    // - note that if the Source record has just been added, fSourceID is not
    // set, so this method will fail: please call the other overloaded method
    function ManyAdd(aClient: TSQLRest; aDestID: Integer;
      NoDuplicates: boolean=false): boolean; overload;
    /// will delete the record associated with a particular Source/Dest pair
    // - will return TRUE if the pair was found and successfully deleted



    function ManyDelete(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean; overload;

    /// will delete the record associated with the current source and a specified Dest
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
    // - note that if the Source record has just been added, fSourceID is not
    // set, so this method will fail: please call the other overloaded method



    function ManyDelete(aClient: TSQLRest; aDestID: Integer): boolean; overload;

    /// will retrieve the record associated with a particular Source/Dest pair
    // - will return TRUE if the pair was found
    // - in this case, all "through" columns are available in the TSQLRecordMany
    // field instance
    function ManySelect(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean; overload;
    /// will retrieve the record associated with the current source and a specified Dest
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
................................................................................
begin
  if fSourceID=nil then
    result := false else // avoid GPF
    result := DestGet(aClient,fSourceID^,DestIDs);
   // fSourceID has been set by TSQLRecord.Create
end;

function TSQLRecordMany.ManyDelete(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean;

var aID: integer;
begin
  result := false;
  if (self=nil) or (aClient=nil) or (aSourceID=0) or (aDestID=0) then
    exit;
  aID := InternalIDFromSourceDest(aClient,aSourceID,aDestID);
  if aID<>0 then


    result := aClient.Delete(RecordClass,aID);
end;

function TSQLRecordMany.ManyDelete(aClient: TSQLRest; aDestID: Integer): boolean;

begin
  if fSourceID=nil then
    result := false else // avoid GPF
    result := ManyDelete(aClient,fSourceID^,aDestID);
end;

function TSQLRecordMany.ManySelect(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean;
begin
  if (self=nil) or (aClient=nil) or (aSourceID=0) or (aDestID=0) then
    result := false else // invalid parameters
    result := aClient.Retrieve(FormatUTF8('Source=:(%): AND Dest=:(%):',

      parameters wrapper for both method callbacks and interface-based services:
      now aParams.Context.ID is to be used insted of aParams.ID 
    - added TJSONObjectDecoder record/object helper for JSON object decoding
      (used e.g. by GetJSONObjectAsSQL() function, and for SQlite3DB process)
    - removed TSQLRecordExternal class type, to allow any TSQLRecord (e.g.
      TSQLRecordMany) to be used with VirtualTableExternalRegister() - there was
      indeed no implementation requirement to force a specific class type
    - added aUseBatchMode optional parameter to TSQLRecordMany.ManyDelete() method
    - now JSON parser will handle #1..' ' chars as whitespace (not only ' ')
    - now huge service JSON response is truncated (to default 20 KB) in logs


  String usage in the Synopse SQLite3 database framework:
    - RawUTF8 is used for every internal data usage, since both SQLite3 and
      JSON do expect UTF-8 encoding
................................................................................
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
    // - note that if the Source record has just been added, fSourceID is not
    // set, so this method will fail: please call the other overloaded method
    function ManyAdd(aClient: TSQLRest; aDestID: Integer;
      NoDuplicates: boolean=false): boolean; overload;
    /// will delete the record associated with a particular Source/Dest pair
    // - will return TRUE if the pair was found and successfully deleted
    // - if aUseBatchMode is TRUE, it will use aClient.BatchDelete() instead
    // of the slower aClient.Delete() method - but you shall call it within
    // a BatchStart / BatchSend block
    function ManyDelete(aClient: TSQLRest; aSourceID, aDestID: Integer;
      aUseBatchMode: boolean=false): boolean; overload;
    /// will delete the record associated with the current source and a specified Dest
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
    // - note that if the Source record has just been added, fSourceID is not
    // set, so this method will fail: please call the other overloaded method
    // - if aUseBatchMode is TRUE, it will use aClient.BatchDelete() instead
    // of the slower aClient.Delete() method - but you shall call it within
    // a BatchStart / BatchSend block
    function ManyDelete(aClient: TSQLRest; aDestID: Integer;
      aUseBatchMode: boolean=false): boolean; overload;
    /// will retrieve the record associated with a particular Source/Dest pair
    // - will return TRUE if the pair was found
    // - in this case, all "through" columns are available in the TSQLRecordMany
    // field instance
    function ManySelect(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean; overload;
    /// will retrieve the record associated with the current source and a specified Dest
    // - source ID is taken from the fSourceID field (set by TSQLRecord.Create)
................................................................................
begin
  if fSourceID=nil then
    result := false else // avoid GPF
    result := DestGet(aClient,fSourceID^,DestIDs);
   // fSourceID has been set by TSQLRecord.Create
end;

function TSQLRecordMany.ManyDelete(aClient: TSQLRest; aSourceID, aDestID: Integer;
  aUseBatchMode: boolean=false): boolean;
var aID: integer;
begin
  result := false;
  if (self=nil) or (aClient=nil) or (aSourceID=0) or (aDestID=0) then
    exit;
  aID := InternalIDFromSourceDest(aClient,aSourceID,aDestID);
  if aID<>0 then
    if aUseBatchMode and aClient.InheritsFrom(TSQLRestClientURI) then
      result := TSQLRestClientURI(aClient).BatchDelete(RecordClass,aID)>=0 else
      result := aClient.Delete(RecordClass,aID);
end;

function TSQLRecordMany.ManyDelete(aClient: TSQLRest; aDestID: Integer;
  aUseBatchMode: boolean=false): boolean;
begin
  if fSourceID=nil then
    result := false else // avoid GPF
    result := ManyDelete(aClient,fSourceID^,aDestID,aUseBatchMode);
end;

function TSQLRecordMany.ManySelect(aClient: TSQLRest; aSourceID, aDestID: Integer): boolean;
begin
  if (self=nil) or (aClient=nil) or (aSourceID=0) or (aDestID=0) then
    result := false else // invalid parameters
    result := aClient.Retrieve(FormatUTF8('Source=:(%): AND Dest=:(%):',

  fSelectOneDirectSQL := fSelectOneDirectSQL+' where ID=?';
  fSelectAllDirectSQL := FormatUTF8('select %,ID from %',[StoredClassProps.SQLInsertSet,fTableName]);
end;

function TSQLRestServerStaticExternal.AdaptSQLForEngineList(var SQL: RawUTF8): boolean;
var Prop: ShortString;
    P: PUTF8Char;
    BPos,RowIDFromPos,TablePos,RowIDWherePos: integer;

    tmp: RawUTF8;
procedure GetFieldProp;
var i,L: integer;
    B: PUTF8Char;
begin
  if P^=#0 then begin
    Prop[0] := #0;
................................................................................
end;
begin
  result := inherited AdaptSQLForEngineList(SQL);
  if result or (SQL='') then
    exit; // found generic 'SELECT * FROM table' query
  // change 'RowID' into 'ID' column name, and SQLTableName into fTableName
  // process 'SELECT Field1,Field2 FROM table WHERE RowID=... AND/OR/NOT Field2='

  RowIDFromPos := 0;
  RowIDWherePos := 0;

  P := pointer(SQL);
  GetFieldProp;
  if Prop<>'SELECT' then exit;

  repeat
    GetFieldProp;
    if Prop='' then exit;
    if Prop='ROWID' then
      if RowIDFromPos>0 then
        exit else
        RowIDFromPos := BPos;
................................................................................
  if Prop='ORDER' then begin // simple ORDER BY clause is accepted
    GetFieldProp;
    if Prop<>'BY' then exit;
    GetFieldProp;
    if not (GotoNextNotSpace(P)^ in [#0,';']) then
      exit; // allow only one column name
    if Prop='ROWID' then
      system.delete(SQL,BPos,3); // 'RowID' -> 'ID'



  end else
  if Prop='WHERE' then
  repeat
    GetFieldProp;
    if Prop='NOT' then
      GetFieldProp; // allow  field1=456 AND NOT field2='Toto'
    if Prop='' then exit;
................................................................................
      repeat inc(P) until P^ in [#0..' ',';',')']; // go to end of value
    P := GotoNextNotSpace(P);
    if PWord(P)^=ord(')')+ord(':')shl 8 then
      inc(P,2); // ignore :(...): parameter
    P := GotoNextNotSpace(P);
    if P^ in [#0,';'] then break; // properly ended the WHERE clause
    GetFieldProp;




    if (Prop<>'AND') and (Prop<>'OR') then exit;
  until false else


  if Prop<>'' then
    exit;














  if RowIDWherePos>0 then
    system.delete(SQL,RowIDWherePos,3); // 'RowID' -> 'ID'
  system.delete(SQL,TablePos,length(StoredClassProps.SQLTableName));
  insert(fTableName,SQL,TablePos); // change table name
  if RowIDFromPos>0 then
    system.delete(SQL,RowIDFromPos,3); // 'RowID' -> 'ID'
  result := true;

  fSelectOneDirectSQL := fSelectOneDirectSQL+' where ID=?';
  fSelectAllDirectSQL := FormatUTF8('select %,ID from %',[StoredClassProps.SQLInsertSet,fTableName]);
end;

function TSQLRestServerStaticExternal.AdaptSQLForEngineList(var SQL: RawUTF8): boolean;
var Prop: ShortString;
    P: PUTF8Char;
    BPos,AfterSelectPos,RowIDFromPos,TablePos,RowIDWherePos,RowIDOrderByPos: integer;
    LimitPos, LimitRowCount,err: integer;
    tmp: RawUTF8;
procedure GetFieldProp;
var i,L: integer;
    B: PUTF8Char;
begin
  if P^=#0 then begin
    Prop[0] := #0;
................................................................................
end;
begin
  result := inherited AdaptSQLForEngineList(SQL);
  if result or (SQL='') then
    exit; // found generic 'SELECT * FROM table' query
  // change 'RowID' into 'ID' column name, and SQLTableName into fTableName
  // process 'SELECT Field1,Field2 FROM table WHERE RowID=... AND/OR/NOT Field2='
  LimitPos := 0;
  RowIDFromPos := 0;
  RowIDWherePos := 0;
  RowIDOrderByPos := 0;
  P := pointer(SQL);
  GetFieldProp;
  if Prop<>'SELECT' then exit;
  AfterSelectPos := BPos;
  repeat
    GetFieldProp;
    if Prop='' then exit;
    if Prop='ROWID' then
      if RowIDFromPos>0 then
        exit else
        RowIDFromPos := BPos;
................................................................................
  if Prop='ORDER' then begin // simple ORDER BY clause is accepted
    GetFieldProp;
    if Prop<>'BY' then exit;
    GetFieldProp;
    if not (GotoNextNotSpace(P)^ in [#0,';']) then
      exit; // allow only one column name
    if Prop='ROWID' then
      RowIDOrderByPos := BPos; // 'RowID' -> 'ID';
    GetFieldProp;
    if Prop='LIMIT' then
      LimitPos := BPos;
  end else
  if Prop='WHERE' then
  repeat
    GetFieldProp;
    if Prop='NOT' then
      GetFieldProp; // allow  field1=456 AND NOT field2='Toto'
    if Prop='' then exit;
................................................................................
      repeat inc(P) until P^ in [#0..' ',';',')']; // go to end of value
    P := GotoNextNotSpace(P);
    if PWord(P)^=ord(')')+ord(':')shl 8 then
      inc(P,2); // ignore :(...): parameter
    P := GotoNextNotSpace(P);
    if P^ in [#0,';'] then break; // properly ended the WHERE clause
    GetFieldProp;
    if Prop='LIMIT' then begin
      LimitPos := BPos;
      break;
    end else
    if (Prop<>'AND') and (Prop<>'OR') then exit;
  until false else
  if Prop='LIMIT' then
    LimitPos := BPos else
  if Prop<>'' then
    exit;
  // handle LIMIT # statement at the end of the SQL
  if LimitPos>0 then begin
    GetFieldProp;
    val(Prop,LimitRowCount,err);
    if err<>0 then
      exit;
    exit;
    // TODO: add LIMIT clause using SynDB.DB_SQLLIMITCLAUSE[]+LimitRowCount
    // (so we need to have DBMS: TSQLDBDefinition at TSQLDBConnectionProperties level)
    system.delete(SQL,LimitPos,P-pointer(SQL)+LimitPos); // erase 'LIMIT #'
  end;
  // convert all 'RowID' to 'ID'
  if RowIDOrderByPos>0 then
    system.delete(SQL,RowIDOrderByPos,3);
  if RowIDWherePos>0 then
    system.delete(SQL,RowIDWherePos,3); // 'RowID' -> 'ID'
  system.delete(SQL,TablePos,length(StoredClassProps.SQLTableName));
  insert(fTableName,SQL,TablePos); // change table name
  if RowIDFromPos>0 then
    system.delete(SQL,RowIDFromPos,3); // 'RowID' -> 'ID'
  result := true;

    '', '', '');

  /// the known function prototypes used to retrieve a mORMot field type
  // from the native type as returned by a TSQLDBSQLGetField function
  DB_COLUMNNATIVETODB: array[TSQLDBDefinition] of TSQLDBColumnTypeNativeToDB = (
    nil, ColumnTypeNativeToDBOracle, nil, nil, nil, nil);
















{$ifdef EMULATES_TQUERY}

{ -------------- TQuery TField TParam emulation classes and types }

type
  /// generic Exception type raised by the TQuery class

    '', '', '');

  /// the known function prototypes used to retrieve a mORMot field type
  // from the native type as returned by a TSQLDBSQLGetField function
  DB_COLUMNNATIVETODB: array[TSQLDBDefinition] of TSQLDBColumnTypeNativeToDB = (
    nil, ColumnTypeNativeToDBOracle, nil, nil, nil, nil);

  /// the known SQL syntax to limit the number of returned rows in a SELECT
  // - Positon indicates if should be included within the WHERE clause,
  // at the beginning of the SQL statement, or at the end of the SQL statement
  // - Insert will replace '%' with the maximum number of lines to be retrieved
  DB_SQLLIMITCLAUSE: array[TSQLDBDefinition] of record
    Position: (posNone, posWhere, posSelect, posAfter);
    Insert: RawUTF8;
  end = (
    (Position: posNone;   Insert:''),
    (Position: posWhere;  Insert:'rownum<=%'),
    (Position: posSelect; Insert:'top %'),
    (Position: posSelect; Insert:'top %'),
    (Position: posAfter;  Insert:'limit %'),
    (Position: posAfter;  Insert:'limit %'));

{$ifdef EMULATES_TQUERY}

{ -------------- TQuery TField TParam emulation classes and types }

type
  /// generic Exception type raised by the TQuery class