def distinct_sql(self, fields):
        if fields:
            raise NotImplementedError('DISTINCT ON fields is not supported by this database backend')
        else:
            return 'DISTINCT'
Fit LinearDiscriminantAnalysis model according to the given
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/db/backends/__init__.py/BaseDatabaseOperations.distinct_sql--crossover with--dataset/ETHPy150Open scikit-learn/scikit-learn/sklearn/discriminant_analysis.py/LinearDiscriminantAnalysis.fit