To answer this question, you need to understand the table-per-class hierarchy and table-per-subclass strategies in Hibernate.

In Hibernate, there are different strategies for mapping inheritance relationships between classes and database tables. The table-per-class hierarchy strategy maps the entire inheritance hierarchy to a single table, using additional columns to differentiate between different subclasses. On the other hand, the table-per-subclass strategy maps each subclass to its own table, with the common attributes in the superclass being duplicated in each subclass table.

Now, let's go through each option to understand why it is correct or incorrect:

Option A) Yes - This option is incorrect because Hibernate does not allow mixing the table-per-class hierarchy and table-per-subclass strategies. You have to choose one strategy for the entire inheritance hierarchy.

Option B) No - This option is correct. Hibernate does not allow mixing the table-per-class hierarchy and table-per-subclass strategies.

Option C) Can't say - This option is incorrect because it is possible to determine whether Hibernate allows mixing these strategies or not.

Option D) None of the above - This option is incorrect because the correct answer is B) No.

The correct answer is B) No. This option is correct because Hibernate does not allow mixing the table-per-class hierarchy and table-per-subclass strategies.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Remove the object and its collections from the first level cache - This option is correct. The session.evict() method in Hibernate removes the object and its collections from the first level cache. The first level cache, also known as the session cache, is associated with the Hibernate session and holds the persistent objects loaded from the database. By evicting the object, you are removing it from the first level cache, and subsequent operations on that object will result in database queries to fetch the object again.

Option B) Remove the object and its collections from the second level cache - This option is incorrect. The session.evict() method does not directly remove the object from the second level cache. The second level cache is a shared cache and is not specific to a particular session. Objects in the second level cache can be accessed by multiple sessions, and removing an object from the first level cache does not automatically remove it from the second level cache.

Option C) Remove the object and its collections from the database - This option is incorrect. The session.evict() method does not remove the object from the database. It only removes it from the first level cache. If you want to delete an object from the database, you would use the session.delete() method instead.

Option D) None of the above - This option is incorrect. Option A is the correct answer.

The correct answer is A) Remove the object and its collections from the first level cache. This option is correct because the session.evict() method in Hibernate removes the object and its collections from the first level cache.

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• Wrong explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Refresh() - This option is correct because the Refresh() method is used to reload an object and all its collections at any time. It is useful when database triggers are used to initialize some of the properties of the object.

Option B) Flush() - This option is incorrect. The Flush() method is used to synchronize the persistence context with the underlying database, but it does not reload objects and their collections.

Option C) Fetch() - This option is incorrect. The Fetch() method is used to retrieve data from the database, but it does not reload objects and their collections.

Option D) Load() - This option is incorrect. The Load() method is used to lazily load an object or collection from the database, but it does not reload objects and their collections.

The correct answer is A) Refresh(). This option is correct because the Refresh() method is specifically designed to reload an object and all its collections at any time.

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• Wrong explanation