Question

你好overflower我有问题我想从数据库中获取可变数据“$ b，$ d，$ f，$ h”然后计算它这是我的例子

<?php
    $host="localhost";
    $username="root";
    $password="root";
    $db_name="cbrteh"

    mysql_connect("$host", "$username", "$password")or die("cannot connect");
    mysql_select_db("$db_name")or die("cannot select DB");

    $b= mysql_query("SELECT bobot FROM atribut where id= 1"); 
    ($row = mysql_fetch_assoc($b));
    $row["bobot"];
    $d= mysql_query("SELECT bobot FROM atribut where id= 2"); 
    ($row = mysql_fetch_assoc($d));
     $row["bobot"];
    $f= mysql_query("SELECT bobot FROM atribut where id= 3"); 
    ($row = mysql_fetch_assoc($f));
    $row["bobot"];
    $h= mysql_query("SELECT bobot FROM atribut where id= 4"); 
    ($row = mysql_fetch_assoc($h));
    $row["bobot"];
    $calc = $b+$d+$f+$h;
    echo $calc;

是我的脚本数据库上的值是50,50,50,50，因此值必须为200 但是我从echo $ calc得到的价值;是22

Answer 1

试试这个：

$b= mysql_query("SELECT bobot FROM atribut where id= 1");
$row = mysql_fetch_row($b);
$b   = $row[0]; 
$d= mysql_query("SELECT bobot FROM atribut where id= 2");
$row = mysql_fetch_row($d);
$d   = $row[0];
[...] // repeat for $f and $h
$calc = $b + $d + $f + $h;
echo($calc);

或者，也许使用任何更合适的代码：

$b= mysql_query("SELECT SUM(bobot) as calc FROM atribut WHERE id IN (1,2,3,4)");
$row = mysql_fetch_row($b);
$calc = $row[0];
echo($calc);

Answer 2

您应该将查询的值存储在变量中，然后对它们求和。

$b = $row["bobot"];

依旧......

php mysql从数据库中获取可变数据并进行计算

2 个答案: