MySQLi / PHP - Pulling data from one database. Inserting into another database

Question

Trying to pull data out of a basic phpmyadmin database.

The code below pulls the data correctly (Commented out section verify). I can write it to the screen and display it. (Not needed just testing) Trying to insert it into another database however and it fails.

I've discovered that the while loops for inserting do not run. Although I can not find out why.

It's a basic localhost database (Testing right now) So the connect data is just temporary.

Any assistance is greatly appreciated Thanks.

<?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();
}
/*
 * 
 */
$questions = mysqli_query($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");
/*
 * These while loops display the content being pulled from the database correctly.
while ($row = mysqli_fetch_array($questions)) {
    echo $row['questionID'] . " : " . $row['question'] . " : " . $row['answers'];
    echo "</br>";
}
while ($row = mysqli_fetch_array($scenarios)) {
    echo $row['scenarioID'] . " : " . $row['scenarioTitle'] . " : " . $row['scenarioInformation'];
    echo "</br>";
}
while ($row = mysqli_fetch_array($results)) {
    echo $row['employeeID'] . " : " . $row['scenarioID'] . " : " . $row['questionID'] . " : " . $row['answers'] . " : " . $row['correct'];
    echo "</br>";
}
while ($row = mysqli_fetch_array($employees)) {
    echo $row['employeeID'] . " : " . $row['firstName'] . " : " . $row['lastName'] . " : " . $row['email'] . " : " . $row['password'];
    echo "</br>";
}
 */
/* //////////////////////////////////////////////////////////////////////////
  Connect to database
 */
$mobhost = 'localhost';
$mobusername = 'root';
$mobpassword = '';
$mobdbname = 'exampletransfer';
$mobcon = mysqli_connect($mobhost, $mobusername, $mobpassword, $mobdbname);
if (mysqli_connect_errno()) {
    echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
/*
 * 
 */
while ($row = mysqli_fetch_array($questions)) {
    mysqli_query($mobcon, "INSERT INTO questions (questionID, question, answers) VALUES (" . $row['questionID'] . ", " . $row['question'] . ", " . $row['answers'] . ")");
}
while ($row = mysqli_fetch_array($scenarios)) {
    mysqli_query($mobcon, "INSERT INTO scenarios (scenarioID, scenarioTitle, scenarioInformation) VALUES (" . $row['scenariosID'] . ", " . $row['scenarioTitle'] . ", " . $row['scenarioInformation'] . ")");
}
while ($row = mysqli_fetch_array($results)) {
    mysqli_query($mobcon, "INSERT INTO results (employeeID, scenarioID, questionID, answers, correct) VALUES (" . $row['employeesID'] . ", " . $row['scenariosID'] . ", " . $row['questionID'] . ", " . $row['answers'] . ", " . $row['correct'] . ")");
}
while ($row = mysqli_fetch_array($employees)) {
    mysqli_query($mobcon, "INSERT INTO employees (employeeID, firstName, lastName, email, password) VALUES (" . $row['employeesID'] . ", " . $row['firstName'] . ", " . $row['lastName'] . ", " . $row['email'] . ", " . $row['password'] . ")");
}
/*
  Close Connections
 */
mysqli_close($webcon);
mysqli_close($mobcon);
/*
 * Error code:
Notice: Undefined index: scenariosID on line 75

Notice: Undefined index: employeesID on line 78

Notice: Undefined index: scenariosID on line 78

Notice: Undefined index: employeesID on line 81
 */
?>

Answer 1

The problem is that you close your $webcon connection and then you try to read from it ^^

You try to do this... Thats not possible ;)

1. Prepare query mysqli_query($webcon, "SELECT * FROM questions");
2. Close connection <<< after that i cant read data
3. Read data

Try this please.

<?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);

Answer 2

Pending it's on the same server and using the same username and password:

// 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());
        }
    }
}

If using MySQLi instead of 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();