mysql - Unknown Column In Where Clause

FROM `T_FORMATIONS`
INNER JOIN `T_COURS` 
  ON `T_SESSIONS`.`SES_ID` = `T_COURS`.`COU_SES_ID`
INNER JOIN `T_SESSIONS` 
  ON `T_FORMATIONS`.`FOR_ID` = `T_SESSIONS`.`SES_FOR_ID`

FROM `T_FORMATIONS`
INNER JOIN `T_SESSIONS` 
  ON `T_FORMATIONS`.`FOR_ID` = `T_SESSIONS`.`SES_FOR_ID`
INNER JOIN `T_COURS` 
  ON `T_SESSIONS`.`SES_ID` = `T_COURS`.`COU_SES_ID`

SELECT `T_COURS`.`COU_DATE`,
  `T_SESSIONS`.*,
  `T_FORMATIONS`.`FOR_TITRE`, 
  `T_FORMATIONS`.`FOR_ID`, 
  `T_FORMATIONS`.`FOR_TITRE`,     
  `T_FORMATIONS`.`FOR_CATEGORIE`,
  `T_FORMATIONS`.`FOR_DESCRIPTION`, 
  `T_FORMATIONS`.`FOR_MIN_PART`, 
  `T_FORMATIONS`.`FOR_MAX_PART`, 
  `T_FORMATIONS`.`FOR_PRIX`, 
  `T_FORMATIONS`.`FOR_LANGUE`
FROM `T_FORMATIONS`
INNER JOIN `T_SESSIONS` 
  ON `T_FORMATIONS`.`FOR_ID` = `T_SESSIONS`.`SES_FOR_ID`
INNER JOIN `T_COURS` 
  ON `T_SESSIONS`.`SES_ID` = `T_COURS`.`COU_SES_ID`
WHERE `T_SESSIONS`.`SES_ETAT` = 1
ORDER BY `T_COURS`.`COU_DATE` ASC, `T_SESSIONS`.`SES_TITRE` ASC, `T_FORMATIONS`.`FOR_TITRE` ASC 
LIMIT 5

SELECT area_id, 
  area_name,
  cont
FROM
(
  SELECT area_id, 
    area_name,
    (select count(*) 
     from applications
     where claims_status=1 
     and center_name=c.area_id) as cont
  FROM apparea c
) c 
where cont<>0

select c.area_id,
  c.area_name,
  a.cont
from apparea c
left join
(
  select count(*) cont,
    center_name
  from applications
  where claims_status=1 
  group by center_name
) a
  on c.area_id = a.center_name

UPDATE HD_TICKET
JOIN USER ON USER.FULL_NAME = HD_TICKET.CUSTOM_FIELD_VALUE11
SET HD_TICKET.CC_LIST =
  CASE WHEN HD_TICKET.CC_LIST = '' OR HD_TICKET.CC_LIST IS NULL THEN USER.EMAIL 
       ELSE CONCAT(HD_TICKET.CC_LIST, ", ", USER.EMAIL)
  END
WHERE HD_TICKET.ID in (<TICKET_IDS>)

UPDATE  practice1 p1,  practice2 p2
    SET p1.`Price` = p2.`COL3`, p1.`Purchaser` = p2.`COL2`
   WHERE p1.`Hip` = p2.`COL1`
   ;

SELECT
    t1.`ID`, t1.`notification_type`, t1.`notification_by`,
    t1.`notification_by_username`, 
    t1.`notification_status`, t1.`notification_date`, t1.`school_key`,
    t1.`class_key`, t1.`post_key`, t1.`extra`, t1.`class_info`,
    t1.`class_subject`,
    (SELECT `notification_last_check` 
    FROM data_users.account_info t2
    WHERE t2.`user_key` = t1.`notification_by` LIMIT 1) AS `notification_last_check` 
FROM `14754931095281411` t1 
WHERE t1.`notification_status` = '10' 
AND t1.`notification_date` > (SELECT `notification_last_check` 
    FROM data_users.account_info t3
    WHERE t3.`user_key` = t1.`notification_by` LIMIT 1) 
ORDER BY `notification_date` DESC LIMIT 10;