jpa mapping java type to database type

Question

Every JPA-Provider (at least hibernate, eclipselink and openjpa) gives the possibility to create the ddl-schema on the basis of the jpa entity classes. But every database management system has his own data types.

So how do the jpa-providers decide which sql datatype will be chosen. (I think it will be provider specific). Is there a Mapping like String->varchar(xx), boolean->tinyint and so on. But then this mapping has to be exist for every database, right? Can anyone put me in the right direction please? I searched in the hibernate source-code but I did not find the right code snippets.

Thanks!

Answer 1

then this mapping has to be exist for every database, right?

You are right. The same is specified in the Dialect which is being used in DB connections.

For whatever I have searched this information is encapsulated inside the dialect driver for the DB which you use and the same must contain the mapping of java types -> db types.

Here you can see mapping in Constructor.