Hi Adriano,
Yes, so in summary , trying to do following -
1) select missing complete or partial PK for any of the tables involved-
exception
2) if any table in select has no PK in config and no ID column in
config/select - exception
3) if any table in select has no PK in config and has ID column in config -
exception
4) if any table in select has no PK in config but has ID column in SELECT -
success
Regards,
Amita
On 7/27/07, Adriano Crestani <[EMAIL PROTECTED]> wrote:
>
> I had the same problem on DAS C++, now it's throwing an exception when it
> finds a row that does not contain all the pk columns.
>
> I'm not used to the DAS Java, but I will explain how I did it on DAS C++,
> maybe this can help you ; )
>
> It reads the ResultSet metadata to find the pk columns. If the PK is
> defined
> on the config, so it look for the columns defined as pk on the config. In
> case it does not find the pk column(or columns if it is a compound pk), it
> looks for the ID columns according to DAS Convention Over Configuration
> rules. Otherwise it throws the exception.
>
> Does it help? : )
>
> Regards,
> Adriano Crestani
>
> On 7/27/07, Amita Vadhavkar <[EMAIL PROTECTED]> wrote:
> >
> > Further on this,
> > Need to consider single and compound PKs case.
> > When select does not include complete PK (all PK columns from compound
> PK)
> > ,
> > DAS needs to throw exception.
> >
> > As a fix proposing below changes:-
> >
> > A>In ResultMetadata - introduce new HashMap tableToPrimaryKeys , fill it
> > during constuctor
> > and provide get method - getAllPKsForTable(tableName).
> >
> > B> In ResultSetRow - add method
> > checkResultSetMissesPK(allTableNamesFromQueryResultSet)
> > which will take each table and check if all PKs are there in result set.
> > If
> > not it will mark that TableData with hasValidPKs=FALSE.
> >
> > C> There is already another check in TableData.addData(), which marks
> this
> > flag FALSE, if any PK in result set has NULL data.
> >
> > B> and C> together will provide complete check
> >
> > D>In ResultSetRow, call,
> > checkResultSetMissesPK(allTableNamesFromQueryResultSet) from
> processRow()
> > and processRecursiveRow(). With this, all TableData will be set with
> > proper
> > hasValidPK, during ResultSetProcessor.processResultSet() and
> consequently,
> > in ResultSetProcessor.addRowToGraph() will be able to do judgement if
> any
> > table is missing PK, in which case DAS will throw RuntimeException and
> > will
> > not form DataGraph.
> >
> > Any comments/suggestions? Based on this I will work on patch for
> > JIRA-1464.
> >
> > Regards,
> > Amita
> >
> > On 7/19/07, haleh mahbod <[EMAIL PROTECTED]> wrote:
> > >
> > > It is best to throw an exception for PK not being there, otherwise an
> > > empty
> > > result set can have two meaning:Empty or something went wrong
> > >
> > > On 7/18/07, Adriano Crestani <[EMAIL PROTECTED]> wrote:
> > > >
> > > > Amita,
> > > >
> > > > There is now way for DAS to keep
> the relationship data consistence
> > > if
> > > > both, pk and fk, are not completely defined. Without them DAS cannot
> > > > predict
> > > > the relationship.
> > > >
> > > > As Brent said, I think it could throw an exception when the PK is
> > > missing,
> > > > no matter if there are relationships or not. Because, as far as I
> > know,
> > > a
> > > > table that has no complete PK retrieved on the ResultSet is being
> > > omitted
> > > > from the graph and I don't think this is a good approach.
> > > >
> > > > But when only the fk is missing, I think it is ok to omit the
> > > relationship
> > > > between the data objects on the graph. This way the user has the
> > option
> > > to
> > > > decide if the references(relationships) will be included or not on
> the
> > > > graph.
> > > >
> > > > Regards,
> > > > Adriano Crestani
> > > >
> > > > On 7/18/07, Brent Daniel <[EMAIL PROTECTED]> wrote:
> > > > >
> > > > > Amita,
> > > > >
> > > > > Definitely, the DAS should enforce the requirement that the PK
> > should
> > > > > be returned for each table in the results. I would consider this a
> > > > > case where the DAS should throw an exception.
> > > > >
> > > > > Brent
> > > > >
> > > > > On 7/18/07, Amita Vadhavkar <[EMAIL PROTECTED]> wrote:
> > > > > > Sorry for the leng thy mail....
> > > > > >
> > > > > > Tried to check the case when the database has parent-child
> tables
> > > and
> > > > > DAS
> > > > > > SELECT Command may/may not
> > > > > > contain the PKs of the tables. And found some quite confusing
> > > > > cases/results,
> > > > > > which are effectively giving
> > > > > > user a wrong impression of the data in tables.
> > > > > >
> > > > > > Looks like there are places where we are allowing partial
> results,
> > > > wrong
> > > > > > association in parent and child rows.
> > > > > > As RDB DAS logic revolves around PKs, can we state clearly that
> > > > > > "When Query SELECT does not include PK for a table, the data
> graph
> > > > will
> > > > > be
> > > > > > empty for that table"
> > > > > > ? i.e. in the below analysis, instead of giving wrong/partial
> > > result,
> > > > at
> > > > > > least consistently give no result?
> > > > > > And make necessary code corrections to adhere to this statement?
> > > > > >
> > > > > > Or any alternative approaches?
> > > > > >
> > > > > > What DAS C++ is doing for this case? Just curious.
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > Say, take below data -
> > > > > > Parent: SINGER(ID, NAME), Child:SONG (ID, TITLE, SINGERID)
> > > > > > Data:
> > > > > > SINGER
> > > > > > ID NAME
> > > > > > --------------------
> > > > > > 1 Jonh
> > > > > > 2 Jane
> > > > > >
> > > > > > SONG
> > > > > > ID TITLE SINGERID
> > > > > > -------------------------------------
> > > > > > 10 ABCD 1
> > > > > > 20 Lamb 1
> > > > > > 30 La ra ra 2
> > > > > >
> > > > > > There are total 8 cases that I can see. viz.
> > > > > >
> > > > > > No relationship in config
> > > > > > --------------------------------------------------
> > > > > > parent PK in SEL child PK in SEL Result
> > > > > >
> > > ----------------------------------------------------------------------
> > > > > > [1] present present correct
> > > > > > [2] present missing wrong
> > > > > > [3] missing present wrong
> > > > > > [4] missing missing wrong
> > > > > >
> > > > > > Relationship in config
> > > > > > [5] present present correct
> > > > > > [6] present missing wrong
> > > > > > [7] missing present wrong
> > > > > > [8] missing missing wrong
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > When relationship is not defined in DAS Config
> > > > > > DAS Client code:
> > > > > > ----------------
> > > > > > DAS das = DAS.FACTORY.createDAS(getConfig("cfg.xml"),
> > > > getConnection());
> > > > > > Command select = das.getCommand("withNoRel-5/6/7/8");
> > > > > > DataObject root = select.executeQuery();
> > > > > > List singers = root.getList("SINGER");
> > > > > > if(singers != null){
> > > > > > System.out.println("Singer size:"+singers.size());
> > > > > > for(int i=0; i<singers.size(); i++){
> > > > > > System.out.println("SINGER NAME:"+
> > > > > > ((DataObject)singers.get(i)).getString("NAME"));
> > > > > > }
> > > > > >
> > > > > > }
> > > > > >
> > > > > > List songs = root.getList("SONG");//as there is no relationship
> > > > > > (explicit/implicit)
> > > > > >
> > > > > > if(songs != null){
> > > > > > System.out.println("Songs size "+songs .size());
> > > > > > for(int ii=0; ii<songs.size(); ii++){
> > > > > > System.out.println("SONG TITLE:"+
> > > > > > ((DataObject)songs.get(ii)).getString("TITLE"));
> > > > > > }
> > > > > > }
> > > > > >
> > > > > > }
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > Result:
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > [1] SELECT SINGER.ID, SINGER.NAME, SONG.ID, SONG.TITLE FROM
> > SINGER,
> > > > SONG
> > > > > > WHERE SINGER.ID = SONG.SINGERID
> > > > > > Singer size:2
> > > > > > SINGER NAME:John
> > > > > > SINGER NAME:Jane
> > > > > > Songs size 3
> > > > > > SONG TITLE:ABCD
> > > > > > SONG TITLE:Lamb
> > > > > > SONG TITLE:La ra ra
> > > > > >
> > > > > > [2] SELECT SINGER.ID, SINGER.NAME, SONG.TITLE FROM SINGER, SONG
> > > WHERE
> > > > > > SINGER.ID = SONG.SINGERID
> > > > > > Singer size:2
> > > > > > SINGER NAME:John
> > > > > > SINGER NAME:Jane
> > > > > > Songs size 1
> > > > > > SONG TITLE:ABCD
> > > > > >
> > > > > > [3] SELECT SINGER.NAME, SONG.ID, SONG.TITLE FROM SINGER, SONG
> > WHERE
> > > > > > SINGER.ID = SONG.SINGERID
> > > > > > Singer size:1
> > > > > > SINGER NAME:John
> > > > > > Songs size 3
> > > > > > SONG TITLE:ABCD
> > > > > > SONG TITLE:Lamb
> > > > > > SONG TITLE:La ra ra
> > > > > >
> > > > > > [4] SELECT SINGER.NAME, SONG.TITLE FROM SINGER, SONG WHERE
> > SINGER.ID=
> > > > > > SONG.SINGERID
> > > > > > Singer size:1
> > > > > > SINGER NAME:John
> > > > > > Songs size 1
> > > > > > SONG TITLE:ABCD
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > When relationship one-to-many (sing) is defined in DAS Config
> > > > > > DAS Client code:
> > > > > > ----------------
> > > > > > DAS das = DAS.FACTORY.createDAS(getConfig("cfg.xml"),
> > > > getConnection());
> > > > > > Command select = das.getCommand("withRel-1/2/3/4");
> > > > > > DataObject root = select.executeQuery();
> > > > > > List singers = root.getList("SINGER");
> > > > > > if(singers != null){
> > > > > > System.out.println("Singer size:"+singers.size());
> > > > > > for(int i=0; i<singers.size(); i++){
> > > > > > System.out.println("SINGER NAME:"+
> > > > > > ((DataObject)singers.get(i)).getString("NAME"));
> > > > > >
> > > > > > List songs =
> ((DataObject)singers.get(i)).getList("sing");
> > > > //use
> > > > > > relationship
> > > > > > if(songs != null){
> > > > > > System.out.println("Songs size "+songs .size()+" for
> > > > singer
> > > > > > :"+((DataObject)singers.get(i)).getString("NAME"));
> > > > > > for(int ii=0; ii<songs.size(); ii++){
> > > > > > System.out.println("SONG TITLE:"+
> > > > > > ((DataObject)songs.get(ii)).getString("TITLE"));
> > > > > > }
> > > > > > }
> > > > > >
> > > > > > }
> > > > > > }
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > Result:
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > > [5] SELECT SINGER.ID, SINGER.NAME, SONG.ID, SONG.TITLE FROM
> > SINGER,
> > > > SONG
> > > > > > WHERE SINGER.ID = SONG.SINGERID
> > > > > > Singer size:2
> > > > > > SINGER NAME:John
> > > > > > Songs size 2 for singer :John
> > > > > > SONG TITLE:ABCD
> > > > > > SONG TITLE:Lamb
> > > > > > SINGER NAME:Jane
> > > > > > Songs size 1 for singer :Jane
> > > > > > SONG TITLE:La ra ra
> > > > > >
> > > > > > [6] SELECT SINGER.ID, SINGER.NAME, SONG.TITLE FROM SINGER, SONG
> > > WHERE
> > > > > > SINGER.ID = SONG.SINGERID
> > > > > > Singer size:2
> > > > > > SINGER NAME:John
> > > > > > Songs size 0 for singer :John
> > > > > > SINGER NAME:Jane
> > > > > > Songs size 1 for singer :Jane
> > > > > > SONG TITLE:ABCD
> > > > > >
> > > > > > [7] SELECT SINGER.NAME, SONG.ID, SONG.TITLE FROM SINGER, SONG
> > WHERE
> > > > > > SINGER.ID = SONG.SINGERID
> > > > > > Singer size:1
> > > > > > SINGER NAME:John
> > > > > > Songs size 3 for singer :John
> > > > > > SONG TITLE:ABCD
> > > > > > SONG TITLE:Lamb
> > > > > > SONG TITLE:La ra ra
> > > > > >
> > > > > > [8] SELECT SINGER.NAME, SONG.TITLE FROM SINGER, SONG WHERE
> > SINGER.ID=
> > > > > > SONG.SINGERID
> > > > > > Singer size:1
> > > > > > SINGER NAME:John
> > > > > > Songs size 1 for singer :John
> > > > > > SONG TITLE:ABCD
> > > > > >
> > > > >
> > > >
> > >
> >
> -------------------------------------------------------------------------------------
> > > > > >
> > > > > > Regards,
> > > > > >
> > > > > > Amita
> > > > > >
> > > > >
> > > > >
> > ---------------------------------------------------------------------
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> > > > >
> > > > >
> > > >
> > >
> >
>
