Is it possible to dynamically define column names in Hibernate / JPA?

Question

So i have this existing DB schema with a number of tables that i want to model with JPA/Hibernate. Each table has the same group of 30 additional columns ( to allow for runt

Answer 1

You need to create a custom NamingStrategy.

Assuming you use spring and hibernate with JPA, here is a configuration snippet with a custom NamingStrategy:

    
    
    
    
        
            
            
            
        
    
    
        
            
                com.yourcompany.CustomNamingStrategy
            
        
    

If you don't use spring, configuration will be different, but you can still use a custom NamingStrategy (see Implementing a NamingStrategy from the Hibernate Documentation).

Anyway, here is a sample NamingStrategy that builds table names of the form TYPE1_TYPE2 for join tables and adds a common prefix to all tables:

public class CustomNamingStrategy extends ImprovedNamingStrategy {

    private static final long serialVersionUID = 1L;
    private static final String PREFIX = "PFX_";

    @Override
    public String classToTableName(final String className) {
        return this.addPrefix(super.classToTableName(className));
    }

    @Override
    public String collectionTableName(final String ownerEntity,
            final String ownerEntityTable, final String associatedEntity,
            final String associatedEntityTable, final String propertyName) {
        return this.addPrefix(super.collectionTableName(ownerEntity,
                ownerEntityTable, associatedEntity, associatedEntityTable,
                propertyName));
    }

    @Override
    public String logicalCollectionTableName(final String tableName,
            final String ownerEntityTable, final String associatedEntityTable,
            final String propertyName) {
        return this.addPrefix(super.logicalCollectionTableName(tableName,
                ownerEntityTable, associatedEntityTable, propertyName));
    }

    private String addPrefix(final String composedTableName) {

        return PREFIX
                + composedTableName.toUpperCase().replace("_", "");

    }

}