Hi, I have put the org.apache.calcite.adapter.csv.CsvScannableTable
and its related classes (Factory, Reader......, etc.) into my test project. When I tried to execute a sql like insert into mysql.calcite_test (select * from csv) an NPE was thrown. where `mysql` is recognised by JdbcSchema#Factory. When I debugged, I found that the bind method of the dynamically generated Bindable code called the JdbcTable's getModifiableCollection() method, which returned null directly. the bind method's subsequent call to collection.size() threw an NPE. This code is generated by EnumerableTableModify.class. After that, I tried to execute insert into mysql.calcite(select * from mysql2.calcite2) There are two JdbcSchema#Factory recognised data sources here, but I found that the code that was eventually generated by JdbcToEnumerableConverter.class executed insert into calcite(select * from mysql2.calcite) in `mysql2` without performing the insert in the `mysql` library. Are these issues intentional with calcite or are they bugs?
