Chuck,
> On 20. 9. 2016, at 10:48 PM, Chuck Hill <[email protected]> wrote:
>
> This is why they are getting inserted again:
> Well, logging out
> "currentUser.editingContext().committedSnapshotForObject(currentUser)['userDataBlock']"
> before saveChanges, I get an empty array. I must admit I don't know whether
> there should be the relationship objects in this snapshot, but anyway:
>
> It should not be an empty array. EOF compares this and the relationship on
> the EO to determine what database operations are needed.
I see.
> I’d start with logging that out just after you fetch/fault currentUser into
> ec (you don’t show that below). If it is empty there, then keep logging to
> see where the data disappears. At this point, I am not ready to guess.
The thing seems empty all the time. Weird. Here's what I log fetch-time:
===
def cbc=.... // the business case whose users are about to be fetched
println "### about to fetch $cbc...\noldSS
${cbc.editingContext().committedSnapshotForObject(cbc).userDataBlocks}"
def xxx=cbc.userDataBlocks()
println "### -> did fetch $xxx\nnewSS
${cbc.editingContext().committedSnapshotForObject(cbc).userDataBlocks}"
xxx.each { println "### user $it\n### rel ${it.dataBlockUsers()}\n### ss
${it.editingContext().committedSnapshotForObject(it).dataBlockUsers}" }
===
Presumably, the “oldSS” should be empty, but the “newSS” should be a copy of
the relationship value (i.e., “cbc.userDataBlocks()”, or “xxx”)?
It is not; the snapshot consistently stays empty:
===
### about to fetch <DBDataBlock@d6ff2f9 PK:1000003 Title:'überblok'
/EC:6350cea5>...
oldSS []
### -> did fetch [<DBUser@6f400a99 PK:1000005 T:'3' Name:'cl' /EC:6350cea5>,
<DBUser@5f8a5755 PK:1000006 T:'3' Name:'c2' /EC:6350cea5>, <DBUser@569a703e
PK:1000009 T:'4' Name:'kl kl kl' /EC:6350cea5>]
newSS []
===
Aside of that, I have added a log into the
DatabaseContextDelegate.databaseContextShouldUpdateCurrentSnapshot method, and
here I *never* get *anything* for the relationships: neither the old (which is
presumable) *nor the new* dictionary ever contain the “userDataBlocks” or
“dataBlockUsers” key — not once.
Well it still might be a wrong model settings as Samuel suggests perhaps? But
it is sort of weird I use this settings for years and lots of M:N's, and this
is the first time I have bumped into this kind of problems.
Can you see what to check next?
Thanks a very big lot,
OC
>
> Also, this is 100% consistent, right? This is not a concurrency issue?
>
> Chuck
>
>
> From: <[email protected]> on behalf
> of "[email protected]" <[email protected]>
> Date: Tuesday, September 20, 2016 at 11:50 AM
> To: "[email protected] WebObjects"
> <[email protected]>
> Subject: EOF inserts already existing M:N relationships/empty snapshot?!?
>
> Hello there,
>
> I have a pretty common setup: entities User and DataBlock, an M:N
> relationship represented by an intermediate entity containing just the two
> keys, flattened on both sides. At both sides the relationships are
> appropriately flattened. Set to own destination+delete rule cascade.
>
> The problem is, upon inserting a new DataBlock and its relationship to a
> current user, beside the two objects which should be inserted (the new
> DataBlock and the new relationship), relationships to other (old) DataBlocks,
> which were before simply _fetched_ for the current user (just to display the
> current state), get inserted too — which, of course, causes an integrity
> constraint violation “this PK already exists“.
>
> My code looks essentially like this:
>
> ===
> EOEditingContext ec= ...
> DBDataBlock ndb=new DBDataBlock()
> ec.insertObject(ndb)
> ndb.addObjectToBothSidesOfRelationshipWithKey(currentUser,'dataBlockUsers')
> // logs here, see below
> ec.saveChanges()
> ===
>
> Immediately before ec.saveChanges(), I log out
>
> (a) ec.insertedObjects(), which contains only one object (I have overridden
> toString() to get the PK /and other attributes, removed here for conciseness/
> of an EO):
>
> [<DBDataBlock@79adaefa PK:null>]
>
> this is all right, null PK means a newly added object, it's the very 'ndb'
> datablock I just have inserted and which I am now saving.
>
> (b) contents of the flattened M:N relationship 'ndb.dataBlockUsers' from the
> DBDataBlock@79adaefa to DBUser, which looks like this:
>
> [<DBUser@71b29988 PK:1000005>]
>
> again, quite all right: only one related user, the currentUser which I have
> just added to the relationship.
>
> (c) contents of the flattened M:N inverse relationship from the current user,
> which looks like this:
>
> [<DBDataBlock@189f083a PK:1000003>, <DBDataBlock@1b47d247 PK:1000016>,
> <DBDataBlock@5f927095 PK:1000019>, <DBDataBlock@54edfe4c PK:1000022>,
> <DBDataBlock@35e1e59c PK:1000023>, <DBDataBlock@793b3d6d PK:1000024>,
> <DBDataBlock@7b06dee8 PK:1000029>, <DBDataBlock@2550aab9 PK:1000033>,
> <DBDataBlock@79adaefa PK:null>]
>
> for the third time, all right: 8 of them previously fetched, already existing
> relationships to other (old) datablocks for the current user, plus one new
> relationship to the newly added DBDataBlock@79adaefa. Perfect so far.
>
> At this moment, ec.saveChanges is performed. I log the database operations
> from databaseContextWillPerformAdaptorOperations delegate method, and it
> looks like this:
>
> ===
> -IN-adaptorOps === SPC: about to perform 10 DB operations |19:54:37.061
> 20.9.16|WorkerThread1
> - 1: INSERT on 'DBDataBlock' 1{uid:1000042}
> - 2: INSERT on 'DB_UserDataBlock' 2{db_id:1000023,
> user_id:1000005}
> - 3: INSERT on 'DB_UserDataBlock' 2{db_id:1000022,
> user_id:1000005}
> - 4: INSERT on 'DB_UserDataBlock' 2{db_id:1000003,
> user_id:1000005}
> - 5: INSERT on 'DB_UserDataBlock' 2{db_id:1000016,
> user_id:1000005}
> - 6: INSERT on 'DB_UserDataBlock' 2{db_id:1000042,
> user_id:1000005}
> - 7: INSERT on 'DB_UserDataBlock' 2{db_id:1000019,
> user_id:1000005}
> - 8: INSERT on 'DB_UserDataBlock' 2{db_id:1000029,
> user_id:1000005}
> - 9: INSERT on 'DB_UserDataBlock' 2{db_id:1000024,
> user_id:1000005}
> - 10: INSERT on 'DB_UserDataBlock' 2{db_id:1000033,
> user_id:1000005}
> ===
>
> i.e., along with inserting the two new objects (1: the new datablock, 6: the
> new relationship), EOF for some darned reason decides to insert _also_ all
> those relationship objects it _fetched_ before! Of course, since they were
> fetched, they already exist in the database, and thus cause an integrity
> constraint violation “this PK already exists“.
>
> Well, logging out
> "currentUser.editingContext().committedSnapshotForObject(currentUser)['userDataBlock']"
> before saveChanges, I get an empty array. I must admit I don't know whether
> there should be the relationship objects in this snapshot, but anyway:
>
> - if not, I have no idea where to find the culprit;
> - if yes, well, the culprit of those inserts is explained, but why on earth
> the snapshot is not properly maintained by EOF?!?
>
> Any idea what might be the culprit, or at least, how to find it? I am afraid
> I am rather out of ideas :/
>
> Thanks a lot,
> OC
>
>
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