Hi
I am new to Hibernate. I just started coding.

Here is my scenario,
I have a table A and which has primary key (say k1), there is an associated table B where the primary key is a composite key( say k2)
k1 + timestamp +type creates the the primary key of table B ie, k2.

Now the tables are already in place and I am now incorporating Hibernate into this.
Here is my question.

For each row in table A there can be 0 or upto 6 rows in table B.
I have designed the HBM.xml and classes for table A to have an associatin set, of table B and the key is composite key and generator class is assigned.In this set declaration i mentioned lazy = true.

I have written Equals() and Hashcode() for classesfor table B.
(B 's objects object 1 = object 2 if the k1 and timestamp and type are equal)


My requirement is to load all rows from table A, with the corresponding set of rows from B where the number of rows inB is exactly 6.

so I have used the query to load all A's where setB.size =6;

Now I have doubt that this defeated the lazy loading cocept since I checked for the size of the set it loaded into the memory during the execution of the above mentioned query.

Can anyone please explain is that true / ho can I identify from the logs if all the rows are loaded on execution of the query itself. ?

Thanks
SKS[/b]

Are you saying you're loading all the A objects into memory then using java to test setB.size() = 6??

If so, hibernate will need to load the B's into memory before doing the test - not the most efficient method.

or...

Are you putting setB.size = 6 in the query?? This is a much better way. Hibernate will generate SQL that counts the B's and only returns A's that have 6 B's.

Additionally, because the B relationship is lazy, it won't load the B's until you access the collection (or force loading through initialize).

If you're going to detach the A objects from the session and want the B's to be populated automatically you can add a "left join fetch" to your HQL query to eagerly load the B's:
"from A as a left join fetch a.setB where a.setB.size = 6"

Turn on show_sql in the hibernate config to see the SQL statements that hibernate generates.