Question

我有功能

function count_where($param, $value)
{
    $result=mysql_query("SELECT COUNT(*) AS TOTAL FROM vote WHERE '$param'='$value'");
    $data=mysql_fetch_assoc($result);
    return $data['TOTAL'];
}

并尝试将其称为

count_where('picture','black circle')

其中picture具有varchar类型（在MySQL中）。它不起作用。

此

$result=mysql_query("SELECT COUNT(*) AS TOTAL FROM vote WHERE picture='black circle'");
 $data=mysql_fetch_assoc($result);
 echo $data['TOTAL'];

工作;

Answer 1

如果要封装列名，请使用反引号`代替撇号'

但要小心，注意sql注入。在运行查询之前，您最好这样做：

$param = mysql_real_escape_string($param);
$value = mysql_real_escape_string($value);

Answer 2

使用这样的反引号替换列名中的单引号：

function count_where($param, $value)
{
    $result=mysql_query("SELECT COUNT(*) AS TOTAL FROM vote WHERE `$param`='$value'");
    $data=mysql_fetch_assoc($result);
    return $data['total'];
}

Answer 3

$result=mysql_query("SELECT COUNT(*) AS TOTAL FROM vote WHERE ".$param."='".$value."'");

我认为这会给你答案

函数与字符串参数

3 个答案: