mORMot Open Source

Hello,

I'm trying to build a concept in which I could switch between SQLite and MySQL storage just with parameter and for standard fields everything works ok, but I have field Data which contains JSON object with some properties, which I would like to read separatly by internal parameters.

Model is defined like this:

TSQLTestTable = class(TSQLRecord)
    private
      FName:RawUTF8;
      FData:variant;
    published
      property Name:RawUTF8 read FName write FName;
      property Data:variant read FData write FData;
  end;

One record for test contains this content in Data field:

{"Param":{"Serial":"123abc"}}

I list records with:

var Table:TSQLTable;
     TmpFields:RawUTF8;
begin
  TmpFields:='ID,JsonGet(Data,'+QuotedStr('Param.Serial')+') as '+QuotedStr('Param.Serial');
  Table:=Database.MultiFieldValues(TSQLTestTable,TmpFields,'');
end;

When I use this code on SQLite database it works ok, but when I run the same code connected to MariaDB I get error:

exception class ESQLite3Exception with message 'Error SQLITE_ERROR (1) [SELECT ID, JsonGet(Data,'Param.Serial') as 'Param.Serial' FROM TestTable] using 3.33.0 - no such column: ID, extended_errcode=1

Problem is only with ID field. If I replace 'ID' with 'Name' which is also in model everything works ok.

I need ID field in result for record references, but I don't know if this is some kind of bug or limitation ?

Thank you for any info.

Hi,

I have found some strange behaviour with TDynArray conversion to JSON (or maybe I am missing something).

If I define array of record which has only integer fields in definition, conversion to JSON fails, but if I add an string to record everything works as expected.

I use XE6 and tested it also with 10.2 CE (both 32bit) and results were the same, I used lastest nightlybuild of mORMot for test.

Definition for array is as such:

type
  TPosition = packed record
    FieldId:integer;
    Width: integer;
//    DummyString:string;
  end;

type TPositions = array of TPosition;

In the following procedure content of TmpJSON is used as conversion target and I have added results in comments:

procedure TForm1.Button1Click(Sender: TObject);
var fPositions:TPositions;
    DAPositions: TDynArray;
    TmpPos:TPosition;
    TmpJSON:RawUTF8;
begin
  DAPositions.Init(TypeInfo(TPositions),fPositions);
  DAPositions.Clear;
  TmpPos.FieldId:=1;
  TmpPos.Width:=50;
  //test if record to JSON is ok
  TmpJSON:=RecordSaveJSON(TmpPos, typeInfo(TPosition));
  //OK we get TmpJSON='{"FieldId":1,"Width":50}'
  DAPositions.Add(TmpPos);
  TmpPos.FieldId:=2;
  TmpPos.Width:=150;
  DAPositions.Add(TmpPos);
  //test if array to JSON is ok
  TmpJSON:=DAPositions.SaveToJSON;
  //ERROR: we get TmpJSON='[214748364801,644245094402]'
  //
  //if we add DummyString:string; to TPosition definition
  //we get correct data: TmpJSON='[{"FieldId":1,"Width":50,"DummyString":""},{"FieldId":2,"Width":150,"DummyString":""}]'
end;

Kind regards,
Bostjan