MySQLi/PHP-从一个数据库中提取数据.正在插入另一个数据库

问题是你关闭了$webcon连接，然后你试图从中读取^^

你试着这么做。。。这是不可能的；）

1. 准备查询mysqli_query($webcon, "SELECT * FROM questions");
2. 关闭连接<lt<之后我就不能阅读数据了
3. 读取数据

请试试这个

<?php
/**
 * Connect to database
 */
$webhost        = 'localhost';
$webusername    = 'root';
$webpassword    = '';
$webdbname      = 'transfertest';
$webcon         = mysqli_connect($webhost, $webusername, $webpassword, $webdbname);
if (mysqli_connect_errno())
{
    echo 'Failed to connect to MySQL: ' . mysqli_connect_error();
}
/**
 * Queries for reading
 */
$questions = mysqli_query($webcon, 'SELECT * FROM `questions`');
$scenarios = mysqli_query($webcon, 'SELECT * FROM `scenarios`');
$results = mysqli_query($webcon, 'SELECT * FROM `results`');
$employees = mysqli_query($webcon, 'SELECT * FROM `employees`');
/**
 * Connect to database
 */
$mobhost        = 'localhost';
$mobusername    = 'root';
$mobpassword    = '';
$mobdbname      = 'exampletransfer';
$mobcon         = mysqli_connect($mobhost, $mobusername, $mobpassword, $mobdbname);
if (mysqli_connect_errno())
{
    echo 'Failed to connect to MySQL: ' . mysqli_connect_error();
}
/**
 * Insert data from old database
 */
// questions
while ($row = mysqli_fetch_array($questions))
{
    // escape your strings
    foreach($row as $key => $val)
    {
        $row[$key] = mysqli_real_escape_string($mobcon, $row[$key]);
    }
    mysqli_query($mobcon, "INSERT INTO `questions` (`questionID`, `question`, `answers`) VALUES ('" . $row['questionID'] . "', '" . $row['question'] . "', '" . $row['answers'] . "');");
}
// scenarios
while ($row = mysqli_fetch_array($scenarios))
{
    // escape your strings
    foreach($row as $key => $val)
    {
        $row[$key] = mysqli_real_escape_string($mobcon, $row[$key]);
    }
    mysqli_query($mobcon, "INSERT INTO `scenarios` (`scenarioID`, `scenarioTitle`, `scenarioInformation`) VALUES ('" . $row['scenariosID'] . "', '" . $row['scenarioTitle'] . "', '" . $row['scenarioInformation'] . "');");
}
// results
while ($row = mysqli_fetch_array($results))
{
    // escape your strings
    foreach($row as $key => $val)
    {
        $row[$key] = mysqli_real_escape_string($mobcon, $row[$key]);
    }
    mysqli_query($mobcon, "INSERT INTO `results` (`employeeID`, `scenarioID`, `questionID`, `answers`, `correct`) VALUES ('" . $row['employeesID'] . "', '" . $row['scenariosID'] . "', '" . $row['questionID'] . "', '" . $row['answers'] . "', '" . $row['correct'] . "');");
}
// employees
while ($row = mysqli_fetch_array($employees))
{
    // escape your strings
    foreach($row as $key => $val)
    {
        $row[$key] = mysqli_real_escape_string($mobcon, $row[$key]);
    }
    mysqli_query($mobcon, "INSERT INTO `employees` (`employeeID`, `firstName`, `lastName`, `email`, `password`) VALUES ('" . $row['employeesID'] . "', '" . $row['firstName'] . "', '" . $row['lastName'] . "', '" . $row['email'] . "', '" . $row['password'] . "');");
}
/*
  Close Connections
 */
mysqli_close($mobcon);
mysqli_close($webcon);

挂起它在同一台服务器上并使用相同的用户名和密码：

// Create a new MySQL database connection
if (!$con = mysql_connect('localhost', $username, $password)) {
    die('An error occurred while connecting to the MySQL server!<br/>' . mysql_error());
}
if (!mysql_select_db($database)) {
    die('An error occurred while connecting to the database!<br/>' . mysql_error());
}
// Create an array of MySQL queries to run
$sql = array(
    'DROP TABLE IF EXISTS `exampletransfer.questions`;',
    'CREATE TABLE `exampletransfer.questions` SELECT * FROM `transfertest.questions`'
);
// Run the MySQL queries
if (sizeof($sql) > 0) {
    foreach ($sql as $query) {
        if (!mysql_query($query)) {
            die('A MySQL error has occurred!<br/>' . mysql_error());
        }
    }
}

如果使用MySQLi而不是MySQL:

// Create a new MySQL database connection
if (!$con = new mysqli('localhost', $username, $password, $database)) {
    die('An error occurred while connecting to the MySQL server!<br/>' . $con->connect_error);
}
// Create an array of MySQL queries to run
$sql = array(
    'DROP TABLE IF EXISTS `exampletransfer.questions`;',
    'CREATE TABLE `exampletransfer.questions` SELECT * FROM `transfertest.questions`'
);
// Run the MySQL queries
if (sizeof($sql) > 0) {
    foreach ($sql as $query) {
        if (!$con->query($query)) {
            die('A MySQL error has occurred!<br/>' . $con->error);
        }
    }
}
$con->close();