Generates a MySQL (maybe generic SQL) expression which converts the stored index of an enum to its constant name. Useful if some jackasses put their constants in the PHP code—not in the database—and you want to see more descriptive values than numbers.

sql_enum_if.py

def sql_enum_if(enum_dict, field):
    """
    Example:
    
    >>> enum_dict = {'CONST_NAME': 1, 'CONST_TWO': 2}
    {'CONST_TWO': 2, 'CONST_NAME': 1}
    >>> sql_enum_if(enum_dict, 'myfield')
    'IF(myfield = 2, "CONST_TWO", IF(myfield = 1, "CONST_NAME", "<unknown>")) AS myfield'
    """
    def _sql_enum_if(items):
        if not items:
            return '"<unknown>"'
        return 'IF(%s = %d, "%s", %s)' % (field, items[0][1], items[0][0], _sql_enum_if(items[1:]))
    return '%s AS %s' % (_sql_enum_if(enum_dict.items()), field)