migrating mysql to mysqli in ajax environment - php

First i would like to say thank you for letting me ask questions again. I know my previous question was a bit low level of knowledge. Today, I would like to ask if the principle of converting mysql to mysqli in ajax is same with html. Suppose this is my Connect.php
<?php
$host = "localhost";
$dbusername = "root";
$dbpassword = "765632";
$dbname = "student";
$link_id = mysqli_connect($host,$dbusername,$dbpassword,$dbname) or die("Error " . mysqli_error($link_id));
?>
and my ajax.php is
<?php
//Connect to MySQL Server
include 'Connect.php';
mysql_connect($host, $dbusername, $dbpassword);
//Select Database
mysql_select_db($dbname) or die(mysql_error());
// Escape User Input to help prevent SQL Injection
$first_name = mysql_real_escape_string(trim($_GET['first_name']));
// Retrieve data from Query
$query = "SELECT student_id, LRN, first_name, last_name, grade, section FROM student_information WHERE first_name LIKE '%{$first_name}%'";
$result = mysql_query($query) or die(mysql_error());
//Generate the output
$searchResults = '';
if(!mysql_num_rows($result))
What are the changes should i made to convert it to mysqli without changing its logical scheme.

Did you mean this?
$link_id = mysqli_connect($host, $dbusername, $dbpassword);
//Select Database
mysqli_select_db($link_id, $dbname) or die(mysqli_error($link_id));
// Escape User Input to help prevent SQL Injection
$first_name = mysqli_real_escape_string($link_id, trim($_GET['first_name']));
// Retrieve data from Query
$query = "SELECT student_id, LRN, first_name, last_name, grade, section FROM student_information WHERE first_name LIKE '%{$first_name}%'";
$result = mysqli_query($link_id, $query) or die(mysqli_error($link_id));
//Generate the output
$searchResults = '';
if(!mysqli_num_rows($result))

Related

how to include a php variable as part of a table name?

I have a site where I needed to use separate table names for each of my clients because the data has to be updated all the time with a manual import.
example:
kansas_users
newyork_users
I have set a global variable as $client which will create the state name on all pages so if I echo "$client"; then I will see "kansas" for example on any page.
I would like to include this variable as part of my SQL query if possible to make it easier to code:
SELECT "nick, firstname, lastname, cell
FROM database.$client_members
where active =1 and id = $user->id";
Is this possible or even safe to do?
Yes it possible you can do some thing like below
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$client = 'kansas';
$table_name = "database." . $conn->real_escape_string($client) . "_members";
$query = sprintf("SELECT nick, firstname, lastname, cell
FROM %s WHERE active = 1 and id = ?", $table_name);
// prepare and bind
$stmt = $conn->prepare($query);
$stmt->bind_param("i", $user->id);
But i think you should seriously consider normalizing your database to avoid such issues

How do I connect my website to a MySQL database?

Below is the code I have in my Sublime, but the database isn't being called.
<?php$username="root";
$password="changedpassword";$database="User";
$field1-name=$_POST['name'];
$field2-name=$_POST['password'];
$field3-name=$_POST['email'];
$field4-name=$_POST['sex'];
$field5-name=$_POST['school'];
$field6-name=$_POST['birth'];
mysql_connect(localhost,$username,$password);
#mysql_select_db($database) or die( "Unable to select database");
$query = "INSERT INTO create_user (name, password, email, sex, school, birth) VALUES('','$field1-name','$field2-name',
'$field3-name','$field4-name','$field5-name','$field6-name')";mysql_query($query);mysql_close();?>
Let's go through this step by step. First, here's your current code, tidied up to be readable:
<?php
$username = "root";
$password = "changedpassword";
$database = "User";
$field1_name = $_POST['name'];
$field2_name = $_POST['password'];
$field3_name = $_POST['email'];
$field4_name = $_POST['sex'];
$field5_name = $_POST['school'];
$field6_name = $_POST['birth'];
mysql_connect(localhost, $username, $password);
#mysql_select_db($database) or die("Unable to select database");
$query = "
INSERT INTO
create_user
(
name,
password,
email,
sex,
school,
birth
)
VALUES
(
'',
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
";
mysql_query($query);
mysql_close();
?>
I've made only two changes (tidied the whitespace, and used _name instead of -name, as PHP variables cannot contain hyphens), but it's already a big improvement. The code is no longer an eyesore. It does not have syntax errors, and it is readable. There are still, though, a large number of problems.
First, you see that we are inserting seven values into six columns. This will be a problem. Fix that by removing the first blank value:
$query = "
INSERT INTO
create_user
(
name,
password,
email,
sex,
school,
birth
)
VALUES
(
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
";
Now we have something that might actually work. It's painfully insecure, with massive potential for SQL injection attacks, and it won't work on the latest PHP because the mysql_ functions have been removed, but it might actually kind of work somewhere. You wouldn't want to put it into production, but for test purposes, we're getting somewhere.
MySQL is deprecated since PHP 5.6 and is insecure, use PDO or MySQLi instead.
Connecting with MySQLi
<?php
//MySQLi information
$db_host = "localhost";
$db_username = "username";
$db_password = "password";
//connect to mysqli database (Host/Username/Password)
$connection = mysqli_connect($db_host, $db_username, $db_password) or die("Error " . mysqli_error());
//select MySQLi dabatase table
$db = mysqli_select_db($connection, "table") or die("Error " . mysqli_error());
$field1_name = $_POST['name'];
$field2_name = $_POST['password'];
$field3_name = $_POST['email'];
$field4_name = $_POST['sex'];
$field5_name = $_POST['school'];
$field6_name = $_POST['birth'];
$query = mysqli_query($connection, "INSERT INTO create_user
(name, password, email, sex, school, birth ) VALUES
(
'$field1_name',
'$field2_name',
'$field3_name',
'$field4_name',
'$field5_name',
'$field6_name'
)
");
Use this and you will be good. I hope this has helped you!

Use PHP variable to search through SQL database

I have a database called $addressdb. I want to search through a table on that database with a result the user inputted ($usersName). My mistake is probably really stupid. I am new with mySQL.
<?php
//IF THE LOGIN is submitted...
if ($_POST['Login']){
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "addressdb";
$usersName = $_POST['users'];
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "SELECT userID, userName FROM users WHERE userName =$usersName";
$result = mysqli_query($conn, $sql);
...
My line of error is
$sql = "SELECT userID, userName FROM users WHERE userName =$usersName";
More specifically the variable call.
Best approach is :
$sql = "SELECT userID, userName FROM users WHERE userName ='".mysqli_real_escape_string($conn, $usersName)."'";
Here it is not so applicable since you are passing the plain text. But when taking data from html page you should use this way.
Try something like this :
$sql = "SELECT userID, userName FROM users WHERE userName = '".$usersName."'";
You need to use quotes around your $userName.
$sql = "SELECT userID, userName FROM users WHERE userName = '$usersName'";
But to be clear, you should escape your user input at least with mysqli_real_escape_string($conn, $userName);

PHP Select fields from database where username equals X

im having problems in PHP with selecting Infomation from a database where username is equal to $myusername
I can get it to echo the username using sessions from the login page to the logged in page.
But I want to be able to select things like 'bio' and 'email' from that database and put them into variables called $bio and $email so i can echo them.
This is what the database looks like:
Any ideas?:/
You should connect to your database and then fetch the row like this:
// DATABASE INFORMATION
$server = 'localhost';
$database = 'DATABASE';
$dbuser = 'DATABASE_USERNAME';
$dbpassword = 'DATABASE_PASSWORD';
//CONNECT TO DATABASE
$connect = mysql_connect("$server", "$dbuser", "$dbpassword")
OR die(mysql_error());
mysql_select_db("$database", $connect);
//ALWAYS ESCAPE STRINGS IF YOU HAVE RECEIVED THEM FROM USERS
$safe_username = mysql_real_escape_string($X);
//FIND AND GET THE ROW
$getit = mysql_query("SELECT * FROM table_name WHERE username='$safe_username'", $connect);
$row = mysql_fetch_array($getit);
//YOUR NEEDED VALUES
$bio = $row['bio'];
$email = $row['email'];
Note 1:
Dont Use Plain Text for Passwords, Always hash the passwords with a salt
Note 2:
I used MYSQL_QUERY for your code because i don't know PDO or Mysqli, Escaping in MYSQL is good enought but Consider Using PDO or Mysqli , as i don't know them i can't write the code with them for you
Simplistic PDO examples.
Create a connection to the database.
$link = new PDO("mysql:host=$db_server;dbname=$db_name", $db_user, $db_pw, array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8"));
$link->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
Use the $link variable when creating (preparing) and executing your SQL scripts.
$stmt = $link->prepare('insert into `history` (`user_id`) values(:userId)');
$stmt->execute(array(':userId' => $userId));
Code below will read data. Note that this code is only expecting one record (with 2 data elements) to be returned, so I'm storing whatever is returned into a single variable (per data element), $webId and $deviceId.
$stmt = $link->prepare('select `web_id`, `device_id` from `history` where `user_id` = :userId');
$stmt->execute(array(':userId' => $userId));
while($row = $stmt->fetch()) {
$webId = $row["web_id"];
$deviceId = $row["device_id"];
}
From the picture I can see you are using phpMyAdmin - a tool used to handle MySQL databases. You first must make a connection to the MySql server and then select a database to work with. This is shown how below:
<?php
$username = "your_name"; //Change to your server's username
$password = "your_password"; //Change to your server's password
$database = "your_database" //Change to your database name
$hostname = "localhost"; // Change to the location of your server (this will prolly be the same for you I believe tho
$dbhandle = mysql_connect($hostname, $username, $password)
or die("Unable to connect to MySQL");
echo "Connected to MySQL<br>";
$selected = mysql_select_db($database, $dbhandle)
or die("Could not select examples");
?>
Then you can write something like this:
<?php
$bio = mysql_query("SELECT bio FROM *your_database_table_name* WHERE username='bob' AND id=1");
?>
and
<?php
$email = mysql_query("SELECT email FROM *your_database_table_name* WHERE username='bob' AND id=1");
?>
Where *your_database_table_name* is the table in the database you selected which you are trying to query.
When I was answering your question, I was referencing this site: http://webcheatsheet.com/PHP/connect_mysql_database.php. So it might help to check it out as well.

Simple table query syntax error?

I hope someone here can help me see where this error is coming from.
I have a form with two fields: email and password. The form's action takes it to a php page that is supposed to
start a session
connect to a database via mysql
run a query and select a row in a table where the email field is similar to the email
submitted in the form.
At this stage it is incomplete, I only echo some of the fields at the end of the script to
see if it works.
I tested it and there was an unexpected end error that came up right at the last line; a bracket I left out. So I though there would be no other errors, but then when I tested it again I got this error:
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '#gmail.com' at line 6
#gmail.com is the last bit of the email I submitted.
Here is the code of the php (action) page:
<?php
session_start();
$_SESSION['sessionemail'] = $_POST['email'];
$_SESSION['sessionpassword'] = $_POST['password'];
$_SESSION['authuser'] = 0;
$dbhost = 'somewhere.com';
$dbuser = 'user';
$dbpass = 'pw';
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
$dbname = 'medreunten_db1';
mysql_select_db($dbname) or die(mysql_error($conn));
$query = 'SELECT
name, smacker, surname, sex, age, nationality, email
FROM
employee
WHERE
email = ' . $_POST['email'];
$result = mysql_query($query, $conn) or die (mysql_error($conn));
extract(mysql_fetch_assoc($result));
while ($row = mysql_fetch_array($result)) {
echo $row['name'];
echo $row['surname'];
echo $row['age'];
}
?>
I tried removed the first 5 lines and I still got the same error.
Somehow, when the php gets parsed, the browser reads the content of the email variable as if it is part of my php code. At least that's what I thought because the error I receive states that there is a problem with the syntax near "#gmail.com".
I hope someone can give me a clue!
You have an SQL injection, always apply mysql_real_escape_string() to any user-submitted or otherwise potentially tampered-with data before sending to a MySQL database.
Note the ' around the email variable.
$email = mysql_real_escape_string($_POST['email']);
$query = "
SELECT name, smacker, surname, sex, age, nationality, email
FROM employee
WHERE email = '$email'
";
<?php
session_start();
$_SESSION['sessionemail'] = $_POST['email'];
$_SESSION['sessionpassword'] = $_POST['password'];
$_SESSION['authuser'] = 0;
$dbhost = 'dedi147.cpt2.host-h.net';
$dbuser = 'medreunten_1';
$dbpass = 'AGqrVrs8';
$conn = mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
$dbname = 'medreunten_db1';
mysql_select_db($dbname) or die(mysql_error($conn));
$query = "SELECT name, smacker, surname, sex, age, nationality, email FROM employee WHERE email = '" . $_POST['email']."'";
$result = mysql_query($query, $conn) or die (mysql_error($conn));
extract(mysql_fetch_assoc($result));
while ($row = mysql_fetch_array($result)) {
echo $row['name'];
echo $row['surname'];
echo $row['age'];
}
?>
try this, should work

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