mysql浮点数计算
select @d1:=growth_ratio from stock_day_info where stock_id='000001' and created='2008-03-26 0';
select @d2:=growth_ratio from stock_day_info where stock_id='000001' and created='2008-03-27 0';
select @d1+@d2;
执行结果:
1.49
1.40
2.8899999999999997
set @d1=1.49;
set @d2=1.40;
select @d1+@d2;
执行结果:
2.890000000000000000000000000000
哪位大虾帮忙解释一下这是为什么?