Thanks Ugo for converting the test.
The mention of EMBEDDED on the Wiki page means that the old test is running in LangHarnessJavaTest only in embedded mode. It should be removed from org.apache.derbyTesting.functionTests.tests.lang.LangHarnessJavaTest now that you are adding the new test. Also the old file AIjdbc.java should be removed.
I think it would be good to run this test in client mode as well to get coverage for the client driver for these ResultSetMetaData methods. I also think it would be good to move the test to the jdbc suite from lang.
I think it was in the wrong suite to start with. It would be nice to have some javadoc, but otherwise your test looks good to me.