Re: [eclipselink-users] Specifying a sequence as the pk generator for a

[Mike Kienenberger <mkienenb@xxxxxxxxx>]

Thanks.

I had already read Mapping_a_Join_Table_with_Additional_Columns.

As a workaround, I had made the join into a separate entity with
many-to-one relationships.   However, I was hoping that another option
was available.

On Thu, Sep 10, 2009 at 10:10 AM, James Sutherland<jamesssss@xxxxxxxxx> wrote:
>
> You cannot put a @GeneratedValue on a @ManyToMany.
>
> Generally if you have additional fields in a join table you need to create
> an object that maps to the join table to map the fields.
> See,
> http://en.wikibooks.org/wiki/Java_Persistence/ManyToMany#Mapping_a_Join_Table_with_Additional_Columns
>
> You can also use a database trigger to auto generate the value, or use
> custom SQL in your EclipseLink ManyToManyMapping (setInsertSQLString()) from
> a DescriptorCustomizer.
>
>
>
> Mike Kienenberger wrote:
>>
>> We have a many-to-many relationship between Receipt and CashBatch.
>>
>> We have a cash_batch_receipt join table with:
>>   - id NUMERIC (primary key)
>>   - cash_batch_id NUMERIC (foreign key to cash_batch)
>>   - receipt_id NUMERIC (foreign key to cash_batch)
>>
>> and a SeqCashBatchReceiptJoin for generating pk values.
>>
>> How can we map this so that the sequence is used to generate the ID pk
>> value?
>>
>> The following did not work.
>>
>>
>> [In JpaCashBatch...]
>>
>>    @ManyToMany(targetEntity=JpaReceipt.class,
>> mappedBy="cashBatchList", fetch=FetchType.LAZY)
>>     @GeneratedValue(strategy=GenerationType.SEQUENCE,
>> generator="SeqCashBatchReceiptJoin")
>>     @JoinTable (
>>         name="cash_batch_receipt_join",
>>         joinColumns=@JoinColumn(name="cash_batch_id",
>> referencedColumnName="id"),
>>         inverseJoinColumns=@JoinColumn(name="receipt_id",
>> referencedColumnName="id")
>>     )
>>
>>
>> [In JpaReceipt...]
>>
>>     @ManyToMany(targetEntity=JpaCashBatch.class, fetch=FetchType.LAZY)
>>     @GeneratedValue(strategy=GenerationType.SEQUENCE,
>> generator="SeqCashBatchReceiptJoin")
>>     @JoinTable (
>>         name="cash_batch_receipt_join",
>>         joinColumns=@JoinColumn(name="receipt_id",
>> referencedColumnName="id"),
>>         inverseJoinColumns=@JoinColumn(name="cash_batch_id",
>> referencedColumnName="id")
>>     )
>>     private List<CashBatchEntity> cashBatchList = null;
>>
>>
>> We get:
>>
>> java.sql.SQLException: ORA-01400: cannot insert NULL into
>> ("CIS"."CASH_BATCH_RECEIPT_JOIN"."ID")
>>
>> Error Code: 1400 Call: INSERT INTO cash_batch_receipt_join
>> (cash_batch_id, receipt_id) VALUES (?, ?) bind => [1002, 1191] Query:
>> DataModifyQuery(sql="INSERT INTO cash_batch_receipt_join
>> (cash_batch_id, receipt_id) VALUES (?, ?)")
>>
>> Thanks!   I couldn't find any information on many-to-many JPA mappings
>> for tables with independent primary keys.
>>
>> Regards,
>> Mike
>>
>
>
> -----
> http://wiki.eclipse.org/User:James.sutherland.oracle.com James Sutherland
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