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Many to Many with out primary keys

 
chiranjeevi gunturu
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Hi,
I got a scenario in many to many association between tables.
I created two tables(TableA and TableB) which are not having primary keys at all.
Now i need to create many to many association to between these two tables. Is this possible ? if yes how to implement that?
Please answer me .
Thanks in advance.

Chiranjeevi
 
Cameron Wallace McKenzie
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You'll need primary keys to do a relational mapping. There must be some way to uniquely identify a row, is there not?

-Cameron McKenzie
 
chiranjeevi gunturu
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Would that be possible if i have composite keys in both the tables?

Thanks
Chiranjeevi
 
Cameron Wallace McKenzie
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For sure, just treat the composite keys like primary keys, and that should do the trick.

How have you mapped the composite keys? There are a variety of ways.

-Cameron McKenzie
 
Justin Chi
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chiranjeevi gunturu wrote:Hi,
I got a scenario in many to many association between tables.
I created two tables(TableA and TableB) which are not having primary keys at all.
Now i need to create many to many association to between these two tables. Is this possible ? if yes how to implement that?
Please answer me .
Thanks in advance.

Chiranjeevi


You have to create a new table for many to many association between TableA and TableB, suppose it is TEST_AB and A is POJO for TableA ,B is POJO for TableB.
Then in A.hbm.xml
.......
<set name="tableABSet" table="TEST_AB">
<key column="A.columnInDB" />
<many-to-many column="B.columnInDB" class="B" />
</set>
.......
Then Hibernate will automaticly populate the data into TEST_AB table in DB whenever you add B to A.
 
Paul Sturrock
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chiranjeevi gunturu wrote:Would that be possible if i have composite keys in both the tables?

Thanks
Chiranjeevi

Composite keys are primary keys - why use them instead of a surrogate or natural key?
 
chiranjeevi gunturu
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Thank you very much all. Now i came to an idea on this. I will try it now!!
Thanks,
Chiranjeevi
 
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