Let Hibernate generate tables ?

hbnusr · **Joined:** Wed Jun 28, 2006 1:03 am **Posts:** 14

Hi all,

I am ok with database design…

But most of the hibernate tutorials and books that I read design the Java classes and let Hibernate create the DB tables and all.

I have already hand-crafted my DB design and all the tables in MySQL. I am not sure whether to throw all that away and let Hibernate generate all tables from java classes.

I am currently starting to map Java classes to my existing DB design/tables. Manually mapping Java’s “short” to MySQL’s “smallint” … for example.

I have a lot of tables. Please advice.

Thanks.

tenwit · **Joined:** Thu Dec 23, 2004 9:08 pm **Posts:** 2008

Don't throw anything away: hibernate is about making your life easier, not harder. Plus, you learn more, faster by using an existing schema: you are going to get loads of mapping errors, constraint violations, etc., all of which will cause you to investigate the ins and outs of mapping properly, resulting in better mappings in your app and a better understanding of hibernate for you.

hbnusr · **Joined:** Wed Jun 28, 2006 1:03 am **Posts:** 14

Thanks for the reply.

But is it better to let Hibernate generate all things on the DB side from Java Domain classes ? Will this cause less problems ? Is this a better way since Hibernate knows best how the DB should match the Java classes ?

I am currently hand-crafting my DB schemas, writing my Java classes and writing the hbm.xml mapping files ... all manually. I am just worried that development will get tougher as development go towards production... as the system becomes more complex.

If there is really a better way (less trouble) of doing things that need me to throw my hand-made DB schema away now... although it will be a waste but I am willing dump it for the sake of experiencing faster development as development progresses.

Pls advice.

Thanks again.

hbnusr · **Joined:** Wed Jun 28, 2006 1:03 am **Posts:** 14

Hi ... I just feel very venerable as just a simple hbm2ddl set to "update"/"create"/"create-drop" and my hand-coded DB DDL codes (tables/foreign key reference integrity etc) will be wiped off and re-written by Hibernate.

I need to know what is the best way to go forward.

hbnusr · **Joined:** Wed Jun 28, 2006 1:03 am **Posts:** 14

In my case, if...if I want to preserve what I have coded in my DB side... my hbm2ddl has to be set to "validate" and only "validate" ?

Is this a good way to proceed with the development ?

Pls advice. Thanks.

hbnusr · **Joined:** Wed Jun 28, 2006 1:03 am **Posts:** 14

Actually...I am rather confused between "validate" and "update" for hbm2ddl.auto.

Can someone explain the difference to me ?

Thanks.