Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 541
  • Last Modified:

why fetch join in hibernate

please see this hibernate tutorial. i have question here

http://72.14.235.132/search?q=cache:Va2qJokS5gwJ:www.metaarchit.com/hibernate_tutorials/Hibernate%2520Tutorial%252004.pdf+Hibernate+Association&cd=9&hl=en&ct=clnk&gl=in&client=firefox-a


see this code given in that tutorial  under   "1.2 Fetching strategies"

<hibernate-mapping package="com.metaarchit.bookshop">
<class name="Book" table="BOOK">
...
<many-to-one name="publisher" class="Publisher" column="PUBLISHER_ID"
lazy="false" fetch="join" />
</class>
</hibernate-mapping>


My Question is , why do we use fetch="join"  in the above ?  if we just  have lazy="false"  then book and chapters both will be loaded .....so why  extra fetch="join"  again ?   i think we can skip fetch="join"  .....i am not clear at this part.
0
cofactor
Asked:
cofactor
1 Solution
 
objectsCommented:
you would do that to avoid the second select, and select the related publisher using a join


0
 
cofactorAuthor Commented:
Ahh...so   this is just a performance issue here ...earlier two select query fired ...now single select query will be fired because of this "join"  thingie  ...good to know ...thanks


thanks


0

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Tackle projects and never again get stuck behind a technical roadblock.
Join Now