I found the solution: I specified the schema in the name of the tables and I have set to true
the property http://www.dbunit.org/features/qualifiedTableNames
(corresponding to org.dbunit.database.FEATURE_QUALIFIED_TABLE_NAMES
).
By this way, my xml code to populate tables look like:
<?xml version='1.0' encoding='UTF-8'?>
<dataset>
<SCHEMA.TABLE ID_FIELD="1" />
</dataset>
where SCHEMA
is the schema name, TABLE
is the table name.
To se the property I've used the following code:
DatabaseConfig dBConfig = dBConn.getConfig(); // dBConn is a IDatabaseConnection
dBConfig.setProperty(DatabaseConfig.FEATURE_QUALIFIED_TABLE_NAMES, true);