'Render the UPDATE..FROM clause specific to MSSQL.
In MSSQL, if the UPDATE statement involves an alias of the table to
be updated, then the table itself must be added to the FROM list as
well. Otherwise, it is optional. Here, we add it regardless.'

def update_from_clause(self, update_stmt, from_table, extra_froms, from_hints, **kw):

    return ('FROM    ' + ',    '.join((t._compiler_dispatch(self, asfrom=True, fromhints=from_hints, **kw) for t in ([from_table] + extra_froms))))
