mysql中计算百分比

 使用ROUND函数:ROUND(num，保留小数位)

SELECT
	ROUND( b.num / a.num * 100, 1 ) AS bz,
	ROUND( c.num / a.num * 100, 1 ) AS hz,
	ROUND( d.num / a.num * 100, 1 ) AS zd,
	ROUND( e.num / a.num * 100, 1 ) AS zx,
	ROUND( f.num / a.num * 100, 1 ) AS xl,
	ROUND( g.num / a.num * 100, 1 ) AS qt 
FROM
	( SELECT count( id ) AS num FROM biz_table ) a,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '1' ) b,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '2' ) c,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '3' ) d,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '4' ) e,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '5' ) f,
	( SELECT count( id ) AS num FROM biz_table WHERE type = '6' ) g