Question

我试图检查数据库中是否已存在字符串。

更新：

if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}

// Start SQL check
$steamid = $_POST["steamid"];


$sql = "SELECT steamid FROM blacklist WHERE steamid = $steamid";


if ($result=mysqli_query($con,$sql))
{
// Return the number of rows in result set
$rowcount=mysqli_num_rows($result);
}

if($rowcount >=1)   
{


    echo "not added as we already have steam id in databse";


}
else
{

echo "code to add it here";
    //SteamID not in database
     //Add it to databse
     $sql = "INSERT INTO blacklist (steamid, permBanned)
            VALUES ('$steamid', false)";

    mysqli_query($con,$sql);
      echo "Added to blacklist";

}       


mysqli_close($con);

插入确实有效，但选择并检查它是否存在并不存在。我不知道为什么？

感谢您的帮助。

（表结构：blacklistID：autonumber，steamid：string，permBanned：bool）

所以我更新了它以尝试使用MySQLi，但我似乎没有随处可见..任何人都可以帮助吗？我真的很感激。

Answer 1

尝试

$sql = mysql_query("SELECT steamid FROM blacklist WHERE steamid =". $steamid);

if(mysql_num_rows($sql)>0)
{


echo "not added as we already have that ID in the database";

}

检查MySQL数据库中是否存在某些内容

1 个答案: