What's the difference beetwen EntityManager and DAO? Is it same thing?
What's the difference beetwen EntityManager and DAO?
1.8k views Asked by Dmitry Oleinik At
1
There are 1 answers
Related Questions in JAVA
- Rails HABTM: Select everything a that a record 'has'
- Best way to make an HABTM association via console
- dynamically create an ical / ics file from a rails model
- Ruby destroy is not working? Or objects still present?
- NoMethodError: undefined method `update_average_rating' for nil:NilClass
- Select results where joined table contains records with an attribute, but without another
- Showing posts only created when boolean was true
- Ruby on rails and HAML - Print a hash with background color
- How can I monitor an endpoint's status with Ruby?
- How to create dynamic pages without form_for helper in Rails?
Related Questions in JAKARTA-EE
- Rails HABTM: Select everything a that a record 'has'
- Best way to make an HABTM association via console
- dynamically create an ical / ics file from a rails model
- Ruby destroy is not working? Or objects still present?
- NoMethodError: undefined method `update_average_rating' for nil:NilClass
- Select results where joined table contains records with an attribute, but without another
- Showing posts only created when boolean was true
- Ruby on rails and HAML - Print a hash with background color
- How can I monitor an endpoint's status with Ruby?
- How to create dynamic pages without form_for helper in Rails?
Related Questions in DAO
- Rails HABTM: Select everything a that a record 'has'
- Best way to make an HABTM association via console
- dynamically create an ical / ics file from a rails model
- Ruby destroy is not working? Or objects still present?
- NoMethodError: undefined method `update_average_rating' for nil:NilClass
- Select results where joined table contains records with an attribute, but without another
- Showing posts only created when boolean was true
- Ruby on rails and HAML - Print a hash with background color
- How can I monitor an endpoint's status with Ruby?
- How to create dynamic pages without form_for helper in Rails?
Related Questions in ENTITYMANAGER
- Rails HABTM: Select everything a that a record 'has'
- Best way to make an HABTM association via console
- dynamically create an ical / ics file from a rails model
- Ruby destroy is not working? Or objects still present?
- NoMethodError: undefined method `update_average_rating' for nil:NilClass
- Select results where joined table contains records with an attribute, but without another
- Showing posts only created when boolean was true
- Ruby on rails and HAML - Print a hash with background color
- How can I monitor an endpoint's status with Ruby?
- How to create dynamic pages without form_for helper in Rails?
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
Popular Tags
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
EntityManager is an interface provided by JPA, which provides generic methods used to persist, merge, find and create queries for entities.
DAO is a pattern used to isolate database-access code in a separate component (the DAO) so that services concentrate on the business logic rather than low-level database stuff. It helps in unit-testing the service, and in separating responsibilities.
When using JPA, you typically write one DAO per entity, that will contain all the JPA code (queries, mostly) related to that entity. And this DAO uses the EntityManager.