def _sql_expand_where(self, spec, key_prefix = '<STR_LIT>', col_prefix = '<STR_LIT>'):
sql = '<STR_LIT>'.join(col_prefix + key +<EOL>( '<STR_LIT>' if spec[key] is None else '<STR_LIT>' ) +<EOL>'<STR_LIT>' + key_prefix + key + '<STR_LIT>' for key in spec)<EOL>params = {}<EOL>for key in spec:<EOL><INDENT>params[key_prefix + key] = spec[key]<EOL><DEDENT>return sql, params<EOL>
Expand a dict so it fits in a WHERE clause

            Logical operator is AND.