Mysql：如何在查询中使用CASE

| 我有以下查询：

SELECT
    t.id as tid
  , t.uid tuid
  , t.bid_type
  , tt.type as type
  , t.bid_category
  , tc.type as category
  , t.name, if(t.description IS NULL
  , \'-\', t.description) as description
  , date_format(t.sdate, \'%m-%d-%Y %H:%i\') as tsdate
  , date_format(t.endate, \'%m-%d-%Y %H:%i\') as tendate
  , date_format(t.adate, \'%m-%d-%Y %H:%i:%s\') as tadate
  , if(t.edate IS NULL, \'-\', date_format(t.edate, \'%m-%d-%Y %H:%i:%s\')) as tedate
  , t.status
  , tq.id as tqid
  , tq.bid
  , if(tq.amount IS NULL, \'-\', tq.amount) as amount
  , if(tq.hand IS NULL, \'-\', tq.hand) as hand
  , if(tq.game = 0 OR tq.game IS NULL, \'-\', tg.type) as game
  , if(tq.stake = 0 OR tq.stake IS NULL, \'-\', ts.type) as stak
  , if(tq.player = 0 OR tq.player IS NULL, \'-\', tq.player) as player
  , if(tq.tourney IS NULL, \'-\', tq.tourney) as tourney
  , if(tq.propbet, \'Prop bet\', \'-\') as propbet
  , if(tq.race, \'Race\', \'-\') as race
  , tq.status as tqstatus 
  , CASE 
    WHEN tq.amount IS NOT NULL THEN tq.amount 
    WHEN tq.hand IS NOT NULL THEN tq.hand 
    WHEN tq.tourney IS NOT NULL THEN tq.tourney 
    WHEN tq.propbet IS NOT NULL THEN \'Prop bet\' 
    WHEN tq.race IS NOT NULL THEN \'Race\' 
    END CASE as bidData
FROM (bid t)
JOIN bid_quote tq ON tq.bid = t.id
JOIN bid_type tt ON tt.id = t.bid_type
                AND tt.pid = 0
JOIN bid_type tc ON tc.id = t.bid_category
JOIN bid_game tg ON tg.id = tq.game
JOIN bid_stake ts ON ts.id = tq.stake

上面提到的查询给出了错误。有人可以指导我如何纠正它，以便CASE在查询中起作用。这是错误： SQL错误（1064）：您的SQL语法有错误；检查与您的MySQL服务器版本相对应的手册以获取正确的语法，以在\'CASE as bidData FROM（bid t）JOIN bid_quote tq ON tq.bid = t.id JOIN bid_ \'附近使用