请大家帮忙看看这句SQL语句有什么问题，执行提示错误

[yhgfriend]

环境 MYSQL5.6

update cash set Balance=Balance- (select Amount from (select * from cash where CashIndex=299) as a),
where Code = (select Code from (select Code from cash where CashIndex=299) as b) and
TheTime > (select TheTime from ((select * from cash) as c) where CashIndex=299) ;

以上是一条SQL语句，分三行在终端里输入，提示有错误，请大家帮忙看一下怎么写才行

[benluobo]

update cash set Balance=Balance- (select Amount from (select * from cash where CashIndex=299) as a), 这一句最后的 逗号去掉