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corchi72

Member

Registered: 2010-12-10

Posts: 232

the class (TSQLRecordMany) can be inherited?

I want to create a class TSQLBaseReport  and then derive it into two class TSQLPDFReport  and TSQLXLSReport ,  and to use that function "HasUser"declared only into TSQLBaseReport  is correct or the framework does not support it. Show  the following example

unit FileTables;

interface

{$I Synopse.inc} 

type
  TSQLFile = Class
  ...
  end;
  TSQLUser = class(TSQLFile)
  ...
  end;
   
  
  TSQLBaseReport = class(TSQLFile)
  private
    fUser: TSQLUserReports;
  public
	function HasUser(ClientDB: TSQLRestClientUri; const AUserName: RawUTF8;
      const AUserID: Integer = -1): Boolean; overload;
    // returned aRowID is an ID of row in PIVOT TABLE !!!
    // so that we can access additional data stored in pivot connection
    function HasUser(ClientDB: TSQLRestClientUri; const AUserName: RawUTF8;
      const AUserID: Integer; var ARowID: Integer): Boolean; overload;virtual;Abstract;
   
  published
    property User: TSQLUserReports read fUser;
  end;
    
  
  TSQLUserBaseReports = class(TSQLRecordMany)
  private
    fSource: TSQLUser;
    fDest: TSQLBaseReport;
  published
    property Source: TSQLUser read fSource;
    property Dest: TSQLBaseReport read fDest;

  end;

  TSQLUserPDFReports = class(TSQLUserBaseReports)
   private
    fSource: TSQLUser;
    fDest: TSQLPDFReport;
  published
    property Source: TSQLUser read fSource;
    property Dest: TSQLPDFReport read fDest;

  end; 

  TSQLUserXLSReports = class(TSQLUserBaseReports)
   private
    fSource: TSQLUser;
    fDest: TSQLXLSReport;
  published
    property Source: TSQLUser read fSource;
    property Dest: TSQLXLSReport read fDest;

  end;   
 
TSQLPDFReport = class(TSQLBaseReport)
  private
    fUsers: TSQLUserPDFReports;
  published
    property Users: TSQLUserPDFReports read fUsers;
  
  end;
  
  TSQLXLSReport = class(TSQLBaseReport)
  private
    fUsers: TSQLUserXLSReports;
  published
    property Users: TSQLUserXLSReports read fUsers;
  
  end;
...  
implementation
...  
function TSQLBaseReport.HasUser(ClientDB: TSQLRestClientUri;
  const AUserName: RawUTF8; const AUserID: Integer = -1): Boolean;
var
  dummy: Integer;
begin
  result := HasUser(ClientDB, AUserName, AUserID, dummy);
end;

function TSQLBaseReport.HasUser(ClientDB: TSQLRestClientUri;
  const AUserName: RawUTF8; const AUserID: Integer;
  var ARowID: Integer): Boolean;
var
  User: TSQLUser;
begin
  result := false;
  ARowID := -1;
  
  fUsers.FillMany(ClientDB, fID);

  while fUsers.FillOne do
  begin
    if fUsers.Dest <> nil then
      try
        User := TSQLUser.Create(ClientDB, Integer(fUsers.Dest));
        if ((AUserID = -1) and (User.Name = AUserName)) or
          ((AUserID > -1) and (User.ID = AUserID)) then
        begin
          result := True; 
          ARowID := fUsers.ID;
          break;
        end;
      finally
        FreeAndNil(User);
      end;
  end;

  
end;

In the following example the user search is performed in the table TSQLPDFReport or in the table  TSQLUserBaseReports.
NB: the TSQL*Base* tables are not created in the database, only derived tables are created

Uses FileTables;

.... 
procedure TForm1.Button1Click(Sender: TObject);
var
 ARec : TSQLXLSReport;
 k:Integer;
begin
try
   ARec := TSQLXLSReport.Create(ClientDB, 1);
   if ARec.ID>0 then
   begin
     if ARec.HasUser(ClientDB,'John')>0 then
	   Showmessage('the 1 report is assigned to John');	  
   end; 	 	   
finally

end;

end;

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,655

Website

Re: the class (TSQLRecordMany) can be inherited?

Your TSQLUserPDFReports class seems to override TSQLUserBaseReports.Source/Dest properties.

This is not correct, from the OOP point of view.

You do not need to define again the properties in inherited classes.

corchi72

Member

Registered: 2010-12-10

Posts: 232

Re: the class (TSQLRecordMany) can be inherited?

However, this only works if I cast TSQLXLSReport(ARec).Users.AddMany (ClientDB, AUser.ID, ARec.ID, true);

procedure TForm1.Button2Click(Sender: TObject);
var
 ARec : TSQLXLSReport;
 k:Integer;
begin
try
   ARec := TSQLXLSReport.Create(ClientDB, 1);
   if ARec.ID>0 then
   begin
      try  
      AUser:=TSQLUSer..Create;
	  AUser.Name := 'John 2'
	  ClientDB.Add(AUser,True);
      AddUser(AUser,ARec);  
	  finally
      AUser.free;	  
	  end;

 
   end; 	 	   
finally

end;

end;

function AddUser(AUser:TSQLUSer;ARec : TSQLBaseReport;):Boolean;
begin

 if not ARec.HasUser(ClientDB,AUser.Name)=0 then
	 ARec.Users.AddMany(ClientDB, AUser.ID, ARec.ID, true);  
	   
end;

right???

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,655

Website

Re: the class (TSQLRecordMany) can be inherited?

You need this because there are "several" Source/Dest published properties in your class.
So the ORM is confused.