一个SQL的效率 求解答
select count(id) as allcount,sum(case when statusreport='-1' then 1 else 0 end) as unknow,sum(case when statusreport='0' then 1 else 0 end) as deliverd,sum(case when statusreport='2' then 1 else 0 end) as fail from msgHistory where 1=1 and SendTime>='2007-01-01' and SendTime<='2013/5/5 0:00:00'
有一千三百万数据，太慢了 怎么加快哦
[解决办法]
where 1=1 and SendTime>='2007-01-01' and SendTime<='2013/5/5 0:00:00'
为什么要这样写？1＝1加上后就索引就不起作用了
看到这个1＝1就深恶痛绝，极坏的编码习惯
