Question

The following code is throwing exception because string field has the SQL reserved word “by” in it. How would I escape this reserved word. The code is meant for google datastore.

String field="Hosted by me"
PersistenceManager pm=PMF.get().getPersistenceManager();
    try{
    Query query=pm.newQuery("select from "+SomeObject.class.getName()
            +" where mField=='"+field+"'");
    _logger.info(query.toString());
    SomeObject=query.execute();
    }finally{
        pm.close();
    }

Here is the exception: :
org.datanucleus.exceptions.NucleusUserException: Query contains a JDOQL keyword (“by”) that is out of order. Keywords can only be used in a defined order.

Answer 1

Try this:

PersistenceManager pm = ...;
try {
  Query quer = pm.newQuery("select from " + SomeObject.class.getName()
                          " where mField == mFieldParam" +
                          " parameters String mFieldParam");
  List<SomeObject> results = (List<SomeObject>) query.execute("Hosted by me");
} finally {
  ...
}