Dynamically Changing Table Names - mysql

Question

I am currently working with a database that has read and write tables.
There are always two tables with the same schema, distinguished by a number as suffix, eg. table1 and table2.
Now, there is another source where I get the current number from. I have to use this number to select from the corresponding table with the matching suffix.
Right now, for every table i have a #MappedSuperclass containing the schema and two implementation classes specifying the table name via #Table(name = "..1") and #Table(name = "..2").
This solution works but by now I discovered a lot of drawbacks and fear there will be many more. Is there another, better way to solve this?
Unfortunately, I could not find out what this kind of database mechanism is called hence I could not find any other sources on the internet.
Thank you in advance!

Answer 1

The most obvious solution:
if ( num == 1 )
{
Table1 table1 = createTable1();
table1.set...;
entityManager.persist( table1 );
} else
{
Table2 table2 = createTable2();
table2.set...;
entityManager.persist( table2 );
}
Or with constructor calling by name (with Lombok annotations):
#Entity
#Data
public class CommonBase
{}
#Entity
#Data
public class Table1 extends CommonBase
{}
#Entity
#Data
public class Table2 extends CommonBase
{}
#Stateless
#LocalBean
public class CommonBaseBean
{
#Inject
private CommonBaseBUS commonBaseBUS;
protected void clientCode()
{
Table0 t0 = (Table0) commonBaseBUS.createEntityByIndex( 0 );
t0.set...();
commonBaseBUS.persisEntity( t0 );
Table1 t1 = (Table1) commonBaseBUS.createEntityByIndex( 1 );
t1.set...();
commonBaseBUS.persisEntity( t1 );
}
}
#Dependent
class CommonBaseBUS
{
#Inject
private CommonBaseDAL commonBaseDAL;
#Setter
private String entityBaseName = "qualified.path.Table";
public CommonBase createEntityByIndex( int index_ ) throws ClassNotFoundException
{
String entityName = entityBaseName + Integer.toString( index_ );
return createEntityByName( entityName );
}
public void persisEntity( CommonBase cb_ )
{
commonBaseDAL.persistEntity( cb_ );
}
protected CommonBase createEntityByName( String entityName_ ) throws ClassNotFoundException
{
Class<?> c = Class.forName( entityName_ );
try
{
return (CommonBase) c.newInstance();
}
catch ( InstantiationException | IllegalAccessException ex )
{
throw new ClassNotFoundException();
}
}
}
#Dependent
class CommonBaseDAL
{
#PersistentContext
private EntityManager em;
public void persisEntity( CommonBase cb_ )
{
em.persistEntity( cb_ );
}
}