Question

PHP+MYSQL查询最大值或最小值!

在PHP+MYSQL中,数据库表price里面有2个字段,一个是ID,一个是PRICE!无索引!都是数字型的!现在在PHP中想根据ID来查询PRICE并取出最大值,输出的字符型为数字型!并赋值给$PMIN.请问如何实现!坐等高手解答!

Answer 1

<?php
//连接数据库
$myconn=mysql_connect("localhost","root","");
mysql_select_db("nowamagic",$myconn);

$strSql="
select article_ID
from article
where article_ID=(select max(article_ID)
from article)
";

$strSql2="
select article_ID
from article
where article_ID=(select min(article_ID)
from article)
";

$result=mysql_query($strSql,$myconn) or die(mysql_error());
$result2=mysql_query($strSql2,$myconn) or die(mysql_error());

$row_max=mysql_fetch_array($result);
$row_min=mysql_fetch_array($result2);

// 输出ID最大值
//echo $row_max["article_ID"];
//echo "
";
// 输出ID最小值
//echo $row_min["article_ID"];

$article_count = $row_max["article_ID"] - $row_min["article_ID"];
?>

Answer 2

$result=Mysql_query("SELECT MAX(price) FROM price");
$row =Myspl_fetch_array($result,MYSQL_NUM);
$PMIN=$row[0];

Answer 3

select MAX(price) from `price`