case when的计算列如何作为查询条件

[w_xxxbbb]

SELECT remiandforcompany.remindid AS "提醒编号",
    vw_defineremind.deptid AS "企业编号",
    vw_defineremind.deptname AS "企业名称",
    vw_defineremind.reminditemname AS "提醒项目名称",
    remiandforcompany.duedate AS "到期日期",
    vw_defineremind.reminddays AS "提醒天数",
        CASE
	WHEN (now()::date > remiandforcompany.duedate::date) THEN '超期'::text
	WHEN (now()::date = remiandforcompany.duedate::date) THEN '到期'::text
        WHEN (now()::date + ((vw_defineremind.reminddays::character varying(10)::text || ' day'::text)::interval)) > remiandforcompany.duedate::date THEN '即将到期'::text
            ELSE NULL::text  END AS "提醒",  --这里有一个计算列，我想让它成为查询条件
    remiandforcompany.truckcode AS "车牌号",
    trucktb.reg_date AS "入户日期",
    trucktb.servicecode AS "运营证编号",
    trucktb.gps,
    trucktb.truckownerid AS "车主编号",
    trucktb.trailercode AS "挂车车牌",
    trucktb.drivercard AS "行车证",
    truckowner.truckownername AS "车主名",
    truckowner.ownercode AS "车主身份证",
    truckowner.tel AS "车主电话"
   FROM vw_defineremind
   JOIN remiandforcompany ON remiandforcompany.reminditemid = vw_defineremind.reminditemid AND remiandforcompany.deptid = vw_defineremind.deptid
   JOIN trucktb ON remiandforcompany.truckcode::text = trucktb.truckcode::text
   LEFT JOIN truckowner ON trucktb.truckownerid = truckowner.truckownerid where 
提醒='超期';--我想让它成为查询条件

[w_xxxbbb]

已解决。postgreSQL这个数据库很不错。就是用的人好像少些。