count 用法 求总条数
$sql="select count(*) as total from e_user"
;
$query =
mysql_query(
$sql,
$link);
$res =
mysql_fetch_array(
$query);
$count =
$res['total'];
max用法
$sql="select max(id) as maxid from e_user"
;
$sql="select id as maxid from e_user order by id desc limit 0,1";
min用法
$sql="select min(id) as minid from e_user"
;
$sql="select id as minid from e_user order by id desc limit 0,1";
sum 用法 求总和
$sql="select sum(id) as total from e_user";
AVG 用法 求平均值
$sql="select avg(id) as total from e_user";
转载于:https://www.cnblogs.com/vania/p/4997198.html
相关资源:数据结构—成绩单生成器