Tag: web technology

Questions Related to web technology

Does hibernate allow mixing table-per-class hierarchy and table-per-subclass strategies?
technology web technology

  1. Yes

  2. No

  3. Can't say

  4. None of the above

Show answer
Correct Option: B

Which statement is correct ?

technology web technology

  1. Session.contains() method to determine if an instance belongs to the session cache.

  2. Session.contains() method to determine if an instance belongs to the data base

  3. Both are correct

  4. None of the above

Show answer
Correct Option: A
Explanation:

To solve this question, the user needs to have knowledge about the Session object in Hibernate.

The Session.contains() method is used to check if a particular object is associated with the current Hibernate session or not.

Option A is correct because the Session.contains() method is used to determine if an instance belongs to the session cache.

Option B is incorrect because the Session.contains() method does not determine if an instance belongs to the database. Instead, it checks whether the instance is associated with the current Hibernate session or not.

Option C is incorrect because only option A is correct.

Option D is incorrect because option A is the correct answer.

Therefore,

The Answer is: A.

What does session.evict() method do ?
technology web technology

  1. remove the object and its collections from the first level cache

  2. remove the object and its collections from the second level cache

  3. remove the object and its collections from the data base

  4. None of the above

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Correct Option: A

Is the Session threadsafe in Hibernate ?
technology web technology

  1. TRUE

  2. FALSE

  3. No matter

  4. None of the above

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Correct Option: B

How can you make a property be read from the database but not modified in anyway

technology web technology

  1. By using the insert="false" and update="false" attributes.

  2. By using the isinsert="false" and isupdate="false" attributes

  3. By using the isinsert="no" and isupdate="no" attributes

  4. None

Show answer
Correct Option: A

Which statement is correct ?
technology web technology

  1. A Session will not obtain a JDBC Connection (or a Datasource) unless it is needed

  2. A Session will obtain a JDBC Connection (or a Datasource) on object create

  3. A Session has no relation with JDBC Connection (or a Datasource)

  4. none of the above

Show answer
Correct Option: A

How to enable query cache in hibernate

technology web technology

  1. hibernate.cache.query_cache true

  2. hibernate.cache.use_query_cache true

  3. hibernate.cache.query_cache yes

  4. none

Show answer
Correct Option: B

If you are not certain that a matching row exists in the database then which method is the best ?
technology web technology

  1. Session.load();

  2. Session.get();

  3. Session.fetch();

  4. None of the above

Show answer
Correct Option: B

Which statement is correct?
technology web technology

  1. bag has index column

  2. bag permits duplicate element values

  3. bag does not permits duplicate element values

  4. None

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Correct Option: B

What does session.createQuery("Query").scroll() return ?
technology web technology

  1. ListResultSet

  2. ResultSet

  3. ScrollableResultSet

  4. ScrollableResult

Show answer
Correct Option: D
Explanation:

To understand what session.createQuery("Query").scroll() returns, the user needs to know about Hibernate and its query methods.

Hibernate is an ORM (Object-Relational Mapping) library that provides an interface between Java classes and SQL databases. It provides several query methods to interact with the database, including session.createQuery().

session.createQuery("Query").scroll() method is used to iterate over a large number of objects without loading them all into memory at once. It returns a ScrollableResults object that can be used to scroll through the results one at a time.

Now, let's go through each option and explain why it is right or wrong:

A. ListResultSet: This option is incorrect because there is no such class as ListResultSet in Hibernate.

B. ResultSet: This option is incorrect because session.createQuery("Query").scroll() does not return a ResultSet object. Hibernate uses a different interface called ScrollableResults for scrolling through large datasets.

C. ScrollableResultSet: This option is incorrect because there is no such class as ScrollableResultSet in Hibernate.

D. ScrollableResult: This option is correct. session.createQuery("Query").scroll() returns a ScrollableResult object that can be used to scroll through the results one at a time.

Therefore, the answer is: D. ScrollableResult.