java保留两位小数问题: 方式一: 四舍五入 double f = 111231.5585; BigDecimal b = new BigDecimal(f); double f1 = b.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue(); 保留两位小数 --------------------------------------------------------------- 方
查jx_score表的平均值,以哪次考试(testid)和科目分组(courseid) select testid, courseid, round(avg(`jx_score`.`score`),2) AS `average` from `jx_score` group by `jx_score`.`testid`,`jx_score`.`courseid`
一.代码 import decimal decimal.getcontext().rounding = decimal.ROUND_HALF_UP def index(number): n = str(number*100) n = decimal.Decimal(n).__round__(1) n = n / decimal.Decimal("100") n = decimal.Decimal(str(n), decimal.getcontext()) return float(n.