PHP won't interface with MySQL in Apache on Raspberry Pi - php

I installed MySql on my Raspberry Pi 2 Model B+ a few days ago to see if I could use it, PHP, phpmyadmin, and Apache to make an accessible database to organize and catalog books that are around the house. I have a table in a MySQL database set up as a prototype with three columns; Booknumber (set to auto-increment), title, and authorLastName. I'm trying to use a form to insert books into table beta, in database bookProof.
Here's the code for the form:
<html>
<body>
<form action="catalog.php" method="POST">
<p>Book Title: <input type="text" name="title"></p>
<p>Author's Last Name: <input type="text name="authorlastname"></p>
</form>
</body>
</html>
Which links to "catalog.php", which is:
<?php
define('DB_NAME', 'bookProof');
define('DB_USER', 'root');
define('DB_PASSWORD', 'root');
define('DB_HOST', 'localhost');
$conn = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
if ($conn->connect_error) {
die("Could not connect: " . $conn->connect_error);
}
$value = $_POST["title"]
$value2 = $_POST["authorlastname"]
$sql = "INSERT INTO beta ('title', 'authorLastName') VALUES ('".$value."', '".$value2."')"
$query = mysqli_query($conn,$sql);
if ($conn->($sql) === TRUE) {
echo "New entry completed successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
When demoform.php is opened, it functions normally, but when the "Add Books" button is clicked, it goes to catalog.php as intended, but the catalog.php page is blank, the table is unchanged, and Google Chrome's "Inspect" tool gives the error:
POST http://192.168.254.11/Library/catalog.php 500 (Internal Server Error) catalog.php:1
If anyone knows how to get the input to the database, please let me know.
Note: This is just a home system, so security is not a priority (I don't need SQL code injection protection).

Your note, "...security is not a priority (I don't need SQL code injection protection)" - you might think that, but you should do it anyways. Not only does it protect your database should your system be exposed (or made public at a later time), it will handle strings automatically for you, so that your query won't break if your strings have quotes ' in them.
One issue is that you're using singlequotes around column and table names. This should be backticks, or none at all. Then you were missing a semicolon ; after defining your $value, $value2 and $sql strings.
Then you're doing something a bit odd - which is also causing a parse-error (Had you enabled error-reporting and checked your logs, you'd see a "Parse error: syntax error, unexpected (" error in your logs), you're querying the table with mysqli_query(), but then you try to do it again - except you're trying to query on the querystring, and not the query method. Note the comments I've added in the code below.
// Don't use singlequotes ' for columns and table-names
// Use backticks ` - quotes are for strings
$sql = "INSERT INTO beta (`title`, `authorLastName`) VALUES ('".$value."', '".$value2."')"; // You were also missing a semicolon here!
// $query = mysqli_query($conn,$sql); // Remove this line, as you're attempting to query it twice
if ($conn->query($sql) === TRUE) { // You're missing the query() method here
echo "New entry completed successfully";
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
Using prepared statements won't be that much of a difference, and you really should do it. There's absolutely no reason to not use prepared statements! Look how little changes that have to be made!
$sql = "INSERT INTO beta (title, authorLastName) VALUES (?, ?)";
if ($stmt = $conn->prepare($sql)) {
$stmt->bind_param("ss", $value, $value2);
$stmt->execute();
$stmt->close();
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
You've also got some invalid HTML which would cause issues - the following line had a missing quote to close off the type attribute.
<input type="text" name="authorlastname">
I suggest you read the following documentation and articles
When to use single quotes, double quotes, and backticks in MySQL
How can I prevent SQL injection in PHP?
PHP manual on mysqli_stmt::bind_param
How to get useful error messages in PHP?
PHP Parse/Syntax Errors; and How to solve them?
As a final note, you should check that the form was submitted and that it has values before inserting into the database. Also, using variable-names like $value and $value2 are not really descriptive - you should avoid it and use proper names for your variables.

Related

Tutorial issues using INSERT INTO without adding a row to database for certain entries

I am following the last part of the following video tutorial "How to create a database website with PHP and mySQL 07 - Add in input form" :
https://www.youtube.com/watch?v=MGIG00d1Xzc&list=PLhPyEFL5u-i0zEaDF0IPLYvm8zOKnz70r&index=7
At the end here is my code, for the inserting portion to the database for the new_jokes.php script (everything up to this point of the series I have gotten to work fine so far)
Basically I am getting the seemingly classic "INSERT INTO" not working although all my syntax looks correct. Am I missing something obvious here? I get no errors, just the row isn't added.
<?php
include "db_connect.php";
$new_joke_question = $_GET["newjoke"];
$new_joke_answer = $_GET["newanswer"];
// Search the database for the word chicken
echo "<h2>Trying to add a new joke and answer: $new_joke_question
$new_joke_answer </h2>";
$sql = "INSERT INTO Jokes_table (JokeID, Joke_question, Joke_answer) VALUES
(NULL, '$new_joke_question', '$new_joke_answer' )";
$result = $mysqli->query($sql);
include "search_all_jokes.php";
?>
Return to the main page
Here is the db_connect.php code as requested:
<?php
// four variables to connect the database
$host = "localhost";
$username = "root";
$user_pass = "usbw";
$database = "test";
// create a database connection instance
$mysqli = new mysqli($host, $username, $user_pass, $database);
?>
Here is search_all_jokes.php (which has minor error checking):
// if there are any values in the table, select them one at a time
if ($mysqli->connect_errno) {
echo "Connection to MySQL failed: (" . $mysqli->connect_errno . ") " .
$mysqli->connect_error;
}
echo $mysqli->host_info . "<br>";
$sql = "SELECT JokeID, Joke_question, Joke_answer FROM Jokes_table";
$result = $mysqli->query($sql);
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
echo "JokeID: " . $row["JokeID"]. " - Joke_question: " .
$row["Joke_question"]. " " . $row["Joke_answer"]. "<br>";
}
} else {
echo "0 results";
}
?>
Also here is the table structure screenshot viewed in myPHPAdmin:
I added error capturing into new_jokes.php inspired by this Stack Overflow post:
INSERT INTO SYNTAX ERROR
And get the following error:
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 't jump.' )' at line 1localhost via TCP/IP
Thank you everyone for helping out with this! Syntax can really throw a wrench in everything. I also will read up on prepared statements since that also could have prevented the issue. The ultimate help to this I found the solution to by adding the function referenced here for MySQLi real_escape_string to clean the single quote I had within the answer I was submitting to my joke table:
(Can a kangaroo jump higher than the empire state building? Of course, the empire state building can't jump.)
As shown in the documentation #miken32 linked as a comment here it is says: "But if $val1 or $val2 contains single quotes, that will make your SQL be wrong. So you need to escape it before it is used in sql; that is what mysql_real_escape_string is for. (Although a prepared statement is better.)"
But now the code for this part 7 of the tutorial on you tube I found works and adds it into a row on the database table, then displaying the full new table on the next webpage. I spent a good while shooting in the dark on while the answer ended up being fairly simple. Again special thanks to #miken32 for pointing me the right direction.
Here is my completed code that ended up working to at least achieve the goal of the tutorial:
<?php
include "db_connect.php";
$new_joke_question = $_GET["newjoke"];
$new_joke_answer = $_GET["newanswer"];
$new_joke_question = $mysqli->real_escape_string($new_joke_question);
$new_joke_answer = $mysqli->real_escape_string($new_joke_answer);
// Search the database for the word chicken
echo "<h2>Trying to add a new joke and answer: $new_joke_question $new_joke_answer
</h2>";
if ($mysqli->connect_errno) {
echo "Connection to MySQL failed: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
}
echo $mysqli->host_info . "<br>";
$sql = "INSERT INTO Jokes_table (JokeID, Joke_question, Joke_answer) VALUES (' ',
'$new_joke_question', '$new_joke_answer' )";
$result = $mysqli->query($sql);
if ($mysqli->query($sql) === TRUE) {
echo 'users entry saved successfully';
}
else {
echo 'Error: '. $mysqli->error .'<br>';
}
include "search_all_jokes.php";
?>
Return to the main page

PHP doesn't send data to MySQL

Have some problem I couldn't find solution for, though searched through many sources (and questions here too). So, here it is.
With the PHP-code below I suppose to collect data from a HTML-form and send it to a local WAMP-server. But, though final check shows me "Success!", no new rows in the database's table are found, it stays empty. Names are correct, commands are (as I see it) too, so I just don't know what's wrong.
I hope you guys could help me. ^^
//Check if user submited a form
if (isset($_POST['submit'])) {
//Check if from is properly filled
if (empty($_POST['itemName']) || empty($_POST['itemPic']) || empty($_POST['itemPrice']) || empty($_POST['itemProvider'])) {
echo '<script>alert ("Fill out the form please!")</script>';
} else {
$conn = new mysqli('localhost:3306', 'root', '', 'goods-review');
//Check if connection established
if (mysqli_connect_errno()) {
exit('Connect failed: ' . mysqli_connect_error());
}
//Sending data
$newItem = array('itemName' => $_POST['itemName'], 'itemPic' => $_POST['itemPic'], 'itemPrice' => $_POST['itemPrice'], 'itemProvider' => $_POST['itemProvider']);
$sql = "INSERT INTO goods (itemName, itemPic, itemPrice, itemDate, itemProvider) VALUES ('" . $newItem['itemName'] . "', '" . $newItem['itemPic'] . "', '" . $newItem['itemPrice'] . "', date('Y:m:d, H:i:s'), '" . $newItem['itemProvider'] . "')";
//Check if sent
if ($sql) {
echo '<script>alert ("Success!")</script>';
} else {
echo '<script>alert ("Error!")</script>';
}
$conn->close();
}
}
The code is just assigning a string value to a variable.
$sql = "INSERT ...";
And the string value is not submitted to the database; it's not being executed as a SQL statement. There's nothing magical about the name of the variable. As far as PHP is concerned, the code is just assigning a value to a variable. That's it.
If you want to execute a SQL statement, you need to add code that actually does that. It shouldn't be difficult to find an example of how to do that.
IMPORTANT NOTE: The code in the question appears to create a SQL statement that is vulnerable to SQL Injection. A much better pattern is to use prepared statements with bind placeholders.
Reference: mysqli_prepare
If there's some (unfathomable) reason that you can't use prepared statements, then at a minimum, any potentially unsafe values that are included in the SQL text must be properly escaped.
Reference: mysqli_escape_string
If you have setup the $newItem array first.
Normaly you will validate the user-input and ensure that the user-input has no SQL injections in it.
Read here about it: What is SQL injection?
After that
(You have to add $newItem['itemDate']=date('Y:m:d, H:i:s');)
$sql = "INSERT INTO goods (".implode(', ',array_keys($newItem)).")"
." VALUES ('".implode("', '",$newItem)."')";
if (mysqli_query($conn,$sql)){
echo '<script>alert ("Success!")</script>';
} else {
echo '<script>alert ("Error!")</script>';
}
If you are using this:
you dont have too keep an eye on the right field order
every field value becomes ' around them
you have less code to write
field count and order can change
Finally mysqli_query() returns FALSE if nothing is insert and you can check for that.
Sidenote: Try to use OOP Version of the MYSQLi Extention and Prepared Statments. Read about it here: mysqli, OOP vs Procedural

How to fix php adding a plain row

I'm making a small project and I'm having some trouble with a php script. Basically, when they enter the text then click 'Enter' It loads to the 'insert.php'. The thing is, if they just visit the insert.php page without going to the main page It enters a plan table which could cause big problems.
Code:
$con=mysqli_connect("localhost","info","info","info");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$_POST[firstname]','$_POST[lastname]','$_POST[age]')";
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
Can you help me fix this problem as It could cause a lot of troubles.
First you need to validate your $_POST variables by using isset().
If they are not submitted from a form, $_POST will be empty. Meaning that when a user try to type in the url, there won't be any post data and your SQL queries won't run.
2nd, you are subject to SQL injection since you are not escaping the content.
I'd suggest escaping each variable by using a prepared statement or mysqli_real_escape_string (less secure but better than nothing).`
if ( isset($_POST) && !empty($_POST['firstname']) && !empty($_POST['lastname']) && !empty($_POST['age'])) {
$con=mysqli_connect("localhost","info","info","info");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
//simple example of escaping variables - BUT NOT AS SECURE AS PREPARED STATEMENT!!
$firstname = $con->real_escape_string($_POST['firstname']);
$lastname = $con->real_escape_string($_POST['lastname']);
$age = $con->real_escape_string($_POST['age']);
//With MySQLi it is best practice to use `prepere`, `bind_param` and `execute:
//or use PDO.
$sql="INSERT INTO Persons (FirstName, LastName, Age)
VALUES
('$firstname','$lastname','$age')";
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
}
Lastly, you were missing the single quotes inside your $_POST variables.
Hope this helps!
This is pretty simple.
if(isset($_POST)):
//all of your code here
endif;
You have to check if $_POST exists to trigger your sql request
if (isset($_POST)){
//script
}
One of the first things that I see right off the top of my head is the fact that you are not checking to ensure that something has infact been typed Into your input box that passes the data to your other file. You can try to use isset() or array_key_exist(). Not to mention these are things that you should be doing anyway.

Simple PHP code for using multiple foreign keys [closed]

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I'm trying to code an order process. I have 3 different tables (orders, product, users) in a single database (dbphesemaas).
What I've tried so far doesn't work:
<?php
$link = mysql_connect('localhost', 'root', '');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('dbphesemaas');
$username=$_POST["username"];
$area=$_POST["area"];
$product=$_POST["product"];
$address=$_POST["address"];
$dol_quantity=$_POST["quantity"];
$query="INSERT INTO orders (id, product_id, address, quantity) VALUES ('$id', '$id2', '$address', '$dol_quantity')";
mysql_close();
?>
Can someone make this code work, the id is a foreign key from users, while the product_id is a foreign key of product?
1. Error handling
You just connect and execute the query.
Well yeah nope - how are you making sure that everything worked?
Let's start off with error handling.
<?php
$link = mysql_connect('localhost', 'root', '');
if (!$link) {
die('Could not connect: ' . mysql_error());
}
mysql_select_db('dbphesemaas');
?>
Is the connection working? Did the database get selected successfully?
You can use the if module to check if it worked.
<?php
// IF $link = mysql_connect('localhost', 'root', '') did not work (note the ! in front of it)
if(!$link = mysql_connect('localhost', 'root', '')){
die('Could not connect to localhost'); // The message displayed. die() will prevent the rest of the script from executing.
}
// IF database "dbphesemaas" did not get selected succesfully (note the ! in front of it)
if(!mysql_select_db('dbphesemaas', $link)){
die('Could not select the database "dbphesemaas"'); // The message displayed. die() will prevent the rest of the script from executing.
}
?>
Now we have the connection working. If something goes wrong, the script will stop being executed and throw a custom error.
2. Unnecessary variables
$username=$_POST["username"];
$area=$_POST["area"];
$product=$_POST["product"];
$address=$_POST["address"];
$dol_quantity=$_POST["quantity"];
Now is my question, why? There is nothing wrong with just using them inside the query. The only reason why you only would make variables is if the old variable is very long (so the chance of typo's are bigger) and/or if the code is too messy in your opinion. Since there is no problem in this code to use the $_POST variable, we're going to scratch this piece of code.
3. The actual query
$query="INSERT INTO orders (id, product_id, address, quantity) VALUES ('$id', '$id2', '$address', '$dol_quantity')";
There are a few problems here:
You wrote the query, but you aren't executing it.
You are using variables ($id, $id2 etc) inside quotes. In the wrong scenario, it's gonna insert $id in the database instead of the actual value.
Once again, no error handling.
No untainting at all. The user can add on into your query and alter the query, making a possible leak and the chance of being hacked bigger. We're going to prevent this with mysql_real_escape_string: http://php.net/manual/en/function.mysql-real-escape-string.php
Looks kinda messy, but that's just a visual problem.
Let's fix these problems:
$query="
INSERT INTO
orders
(
id,
product_id,
address,
quantity
)
VALUES
(
'". mysql_real_escape_string($_POST['id']) ."',
'". mysql_real_escape_string($_POST['id2']) ."',
'". mysql_real_escape_string($_POST['adress']) ."',
'". mysql_real_escape_string($_POST['quantity']) ."'
)
";
if(mysql_query($query)){
echo 'Succesfully executed the query.';
}
else
{
echo 'Query not executed - MySQL error. <br>';
echo '<pre>'. mysql_error() .'</pre>';
}
Using '". (random php code) ."' allows php code to be executed within a string. For example:
$variable = 'This is text '. strtoupper('this is capitalized since strtoupper makes this capital. note that this is inside the string.') .' and this is once again lowercase.';
4. Keep this for the future
The way I wrote these codes are useful for the future. Keep the use tabs every time you open/add a new bracket ({).
Further info - the default mysql_* functions are going to be deprecated as of PHP 5.5 - Use MySQLi in the future, it's the improved version. Info: http://www.php.net/manual/en/book.mysqli.php
5. For your actual problem
One mysql_query can only execute one query. You can do this:
$queries = array();
$errors = array();
$queries[] = 'INSERT INTO ... '; // using $variable[] will add another entry to the $variable array.
$queries[] = 'INSERT INTO ... ';
$queries[] = 'UPDATE bla SET ...';
foreach($queries as $query){
// Foreach will seperate the entries in an array
// IF mysql query failed
if(!mysql_query($query)){
$errors[] = mysql_error(); // We'll add the errors to an array aswell.
}
}
// Check if there are entries in the $failures array.
if(count($errors) > 0){
echo 'We had some MySQL errors.';
echo '<ul>';
foreach($errors as $failure){
echo '<li>'. $failure .'</li>';
}
echo '</ul>';
}
else
{
echo 'No errors - MySQL queries executed succesfully.';
}
Hope this helps you on your way.

postgres update through php

I am a complete novice at php and postgres. I have been searching all over the net for an answer but no joy! I have a postgres table called workorders. It has a primary key (ident). I am trying to up date it using a php script/program. Basically the ident is the workorder number. I have written a php script where i type in the workorder number, post it to another php file, which connects to the database, finds the ident that matches and updates it by adding 'paid' to a column called paid. I have made it work using INSERT into, but it will not allow duplicate keys so that is why i am trying to use update. When I do, it says "unexpected T_CONSTANT_ENCAPSED_STRING"
Help would be greatly appreciated.
<?php
include('adodb5/adodb.inc.php');
$DB = &ADONewConnection('postgres');
$DB->PConnect('host=localhost port=5432 dbname=test user=postgres password=secret');
if (!$DB) {
die("Error in connection: " . pg_last_error());
}
$arr = array( array('paid',$_POST['$invoice']), );
$ok = $DB->Execute('insert into workorders (paid, ident) values (?,?)',$arr);
if (!$ok) {
die("Invoice not posted. " . pg_last_error ());
}
?>
If I use this I can insert into my database. If I replace INSERT into with UPDATE or pg_update I get errors.
Have now seen your code, which looks fine.
T_CONSTANT_ENCAPSED_STRING is often the result of not escaping quotation marks when used in strings. But I am not seeing that here. Can you post the example that does not work?
include('adodb5/adodb.inc.php');
$DB = &ADONewConnection('postgres');
$DB->PConnect('host=localhost port=5432 dbname=test user=postgres password=secret');
if (!$DB) {
die("Error in connection: " . pg_last_error());
}
$arr = array( array('paid',$_POST['$invoice']), );
$ok = $DB->Execute('insert into workorders (paid, ident) values (?,?)',$arr);
if (!$ok) {
die("Invoice not posted. " . pg_last_error ());
}

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