Question

我有问题。现在需要大约5个小时，我没有解决它。

如果我设置$ dbName =＆＃34; dbTest＆＃34;直接在php文件中，它的工作原理。（见代码中的评论）。

如果我通过$ dbName = $ _POST [＆＃34; dbName＆＃34;]传递我的数据库名称，我得到以下错误：＆＃34; Ther是运行查询的错误[未选择数据库]＆＃34;

我不相信这个！请帮忙。

<?php
     if (isset($_POST['dbName'])) {
        $dbName = $_POST["dbName"];

        function db_connection($query) 
             global $dbName;

                echo $dbName //dbTest
                echo strcmp ($dbName,'dbTest') //always 0 (equal)
                // $dbName ='dbTest' // if I comment this out, it works!
                $db = new mysqli('localhost', 'user', 'password', $dbName);

                if ($db->connect_errno > 0) {
                   die('Unable to connect to database [' . $db->connect_error . ']');
                } 

                if (!$result = $db->query($query)) {
                    die('There was an error running the query [' . $db->error . ']');
                }
             }
    }
?>

Answer 1

试试这个：

<?php
$dbName = $_POST["dbName"];
$query = 'SELECT * FROM TABLE'; // query example or if comes via [$_POST][1] $query = $_POST['query'];
$connection = db_connection($query, $dbName);

function db_connection($query $dbName) {
     global $dbName;


    echo $dbName //dbTest
    echo strcmp ($dbName,'dbTest') //always 0 (equal)
    // $dbName ='dbTest' // if I comment this out, it works!
    $db = new mysqli('localhost', 'user', 'password', $dbName);

    if ($db->connect_errno > 0) {
       die('Unable to connect to database [' . $db->connect_error . ']');
    } 

    if (!$result = $db->query($query)) {
        die('There was an error running the query [' . $db->error . ']');
    }
}
?>

Answer 2

添加isset以验证您是否正在发送值：http://php.net//manual/en/function.isset.php

<?php
     if (isset($_POST['dbName'])) {
        $dbName = $_POST["dbName"];

        function db_connection($query) 
             global $dbName;

                echo $dbName //dbTest
                echo strcmp ($dbName,'dbTest') //always 0 (equal)
                // $dbName ='dbTest' // if I comment this out, it works!
                $db = new mysqli('localhost', 'user', 'password', $dbName);

                if ($db->connect_errno > 0) {
                   die('Unable to connect to database [' . $db->connect_error . ']');
                } 

                if (!$result = $db->query($query)) {
                    die('There was an error running the query [' . $db->error . ']');
                }
             }
    }
?>

希望这会有所帮助：）

通过$ _POST-value发送数据库名称不起作用

2 个答案: