MySQL SQL statement parsing

SELECT
a.ID
, b.order_id,b.attr
From
Tourist_order A
Left JOIN order_attr b
On a.id = b.order_id
and b.attr= ' Order_status '
WHERE
b.order_id is NULL
and a.create_type!=19
and a.added_time>= ' 2014-01-01 '
and a.sign_date= ' 0000-00-00 '
and A.back_time>now ()
# and a.id=3526098

The goal is to query the table table for order numbers that do not have attr equal to "Order_status"

Placing and b.attr= ' Order_status ' is not the same as before and where.

The statement following the where will filter the results of the previous left join