Which Hibernate Saving Method Should You Use?

Understanding the Differences Between Hibernate's Saving Methods

In the Hibernate ORM framework, there is a range of methods that allow users to persist objects into a database. Each method serves a specific purpose and has distinct characteristics. Here's a deeper dive into the differences between these methods:

save()

• Purpose: Persists a new object in the database.
• Behavior: Assigns an identifier to the object if it does not already have one. If the object has an existing identifier, it essentially updates the object's state in the database.
• Usage: Ideal for creating new records in the database.

update()

• Purpose: Updates an existing object in the database.
• Behavior: Requires the object to have an existing identifier. Attempts to persist the object using that identifier. If the identifier is missing, it typically throws an exception.
• Usage: Suitable for updating already existing records in the database.

saveOrUpdate()

• Purpose: Invokes either save() or update() based on certain checks.
• Behavior: If the object does not have an identifier, save() is called. Otherwise, update() is used.
• Usage: Can be used to create or update an object, providing versatility.

saveOrUpdateCopy()

• Deprecated: This method is no longer recommended. Instead, use merge().

merge()

• Purpose: Merges a detached or transient object into the persistent context.
• Behavior: The main difference lies in the concept of object states. Detached or transient objects are not associated with a Hibernate session. To update or save such objects, merge() must be used.
• Usage: Ideal for updating or saving detached or transient objects.

persist()

• Purpose: Similar to merge(), it is used for transient objects.
• Behavior: Persists a transient object into the database. It does not return the generated identifier.
• Usage: Suitable for saving new transient objects without requiring an immediate identifier.

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