摘要：
select date, count(fail) as fail,count(win) as win from (select date,(case (result) when 'fail' then 'fail' end ) as fail,(case (result) when 'win' th 阅读全文
摘要：
var a = {n: 1};var b = a;a.x = a = {n: 2};这里面第三句可以直接拆解为：a.x = {n : 2};a = {n : 2};a.x 赋值的时候，和b还是引用的同一个内存地址，a赋值的时候，a的内存地址就指向了{n:2}，最后a.x是undefined，b.x是 阅读全文