MormotSqlite3.MainEngineList doesn't rise exception

mariomoretti · 2017-05-31 06:47:59

Hi AB,

in line 1337 of unit in subject there are these istructions .

      except
        on E: ESQLite3Exception do
          GetAndPrepareStatementRelease(E);
      end;

createandfillprepare , in case of exception, returns a null resultset without any advertisement.
This means that i have , every time , to check for tSqlRsetServerDB.StatementLastException to be sure that all worked fine ?
Now i'm only catching exceptions.

ab · 2017-05-31 06:57:08

By design, exceptions can't be propagated over a network.
Since all this DB process may be run remotely, the exceptions are catch on server side.

So yes, you have to check for a null result set, as documented.
A valid request, returning no result row, will never be null - but only with column names.

mariomoretti · 2017-05-31 07:12:00

Tx AB.

mariomoretti · 2017-05-31 07:14:33

Anhoter question please :

on server side , what object, instead of tMySQLRestServerDB, I should better use to access data by ORM?

ab · 2017-05-31 07:44:51

If you can, you may just define and inject a TSQLRest instance dependency on server side.

mariomoretti · 2017-05-31 08:20:09

Well,

one thing i have clear , i am totally confused and thick as a brick !!

Sorry to annoying you with newby questions, but i'm trying to put order in my mind :

- a tSQLRestServerDb runs only on server side.
- I'm using a tSQLClientRestURI to run processes from remote.
- so , why a tSQLRestServerDB.CreateAndFillPrepare doesn't return an exception ?

ab · 2017-05-31 08:35:14

Because ORM methods do implement the Liskov substitution principle, so they follow abstract TSQLRest expectations, which may be a client or server implementation.

If the server does not behave the same as the client (i.e. raise an exception whereas the client won't), then the Liskov principle is broken.

mariomoretti · 2017-05-31 11:02:19

Sounds a very good reason.

I have added a control of StatementLastException after the createandfillprepare nested in transaction : now seems to work ok.

tx very much AB.

mORMot Open Source

#1 2017-05-31 06:47:59

MormotSqlite3.MainEngineList doesn't rise exception

#2 2017-05-31 06:57:08

Re: MormotSqlite3.MainEngineList doesn't rise exception

#3 2017-05-31 07:12:00

Re: MormotSqlite3.MainEngineList doesn't rise exception

#4 2017-05-31 07:14:33

Re: MormotSqlite3.MainEngineList doesn't rise exception

#5 2017-05-31 07:44:51

Re: MormotSqlite3.MainEngineList doesn't rise exception

#6 2017-05-31 08:20:09

Re: MormotSqlite3.MainEngineList doesn't rise exception

#7 2017-05-31 08:35:14

Re: MormotSqlite3.MainEngineList doesn't rise exception

#8 2017-05-31 11:02:19

Re: MormotSqlite3.MainEngineList doesn't rise exception

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