How to make Where clause dynamic in mysql - php

After logging into ones account and clicking 'Accept' button the system should insert a sequence of numbers in mysql table under "otp" column for validation purpose. The problem here is I want to make it dynamic in the WHERE clause. It should recognize and insert otp according to user ids itself.
Following is the code.
if(isset($_POST['generate']))
{
$num = (rand(111111, 999999));
file_get_contents("somelink");
$query = mysqli_query($con, "UPDATE users SET otp='".$num."' WHERE id = 21");
$qry_run = mysqli_query($con, $query);
mysqli_close($con);
header("location: otp.php");
}

You should not use var concatenated with your sql .. this behavior can allow sql injection so you should use prepare bind_param and execute
and assuming you have in var the valure for match the id you coould use this var for param too
$con = $con->prepare("UPDATE users SET opt = ? WHERE id = ?");
$con->bind_param('ii', $num, $id);
$num = (rand(111111, 999999));
$id = 21;
$con->execute();
mysqli_close($con);

Have you thought about using RAND() in SQL?
UPDATE users SET otp = RAND() WHERE id = 21

Related

PHP MySQL Update Query not working with vars

$ID = trim($_GET["uid"]);
$Name = trim($_GET["name"]);
$result = $mysqli->query("UPDATE `Benutzer` SET `R_NAME`='$Name' WHERE `ID` = '$ID'");
The Result returns fine, but the Database is not updated. If I replace the vars with static values the Database IS updated.
Use mysqli prepare statement.
$stmt = $mysqli->prepare("UPDATE Benutzer SET R_NAME = ? WHERE ID = ?");
$stmt->bind_param($Name,$ID);
$stmt->execute();
$stmt->close();
Follow these steps:
Remove "trim" & use "mysql_escape_string".
Echo Check the values of Name & ID. Once you are getting them then follow up with the 3rd step.
Concatinate the sql string as shown by removing the tild operators:
$result = $mysqli->query("UPDATE Benutzer SET R_NAME ='".$Name."' WHERE ID = '".$ID."'");
What we pass in the query arguments is a string or we can say query in the form of string. you can change the query like below.
$result = $mysqli->query("UPDATE `Benutzer` SET `R_NAME`='".$Name."' WHERE `ID` = '".$ID."'");

Trying to fill a PHP variable with a mysql query. Then updating another table with the data from that query

First post, here it goes.
So this is the code that I have so far:
include('Connection/connect-test.php');
$selected1 = $_POST['selected'];
$sqlget = "SELECT paymentid FROM highschoolpayment WHERE hsgameid = '$selected1'";
$sqldata = mysqli_query($dbcon, $sqlget);
$sqlupdate = "UPDATE highschool SET paymentid = '$sqldata' WHERE hsgameid = '$selected1'";
mysqli_query($dbcon, $sqlupdate);
What I'm trying to do is grab the 'paymentid' from the 'highschoolpayment' table and store that value into the $sqldata variable (line 4). Then I want to update a value in the 'highschool' table using the value that I got from line 4 as well as a value that was pulled from a POST submission (line 6). I know for a fact that the first 3 lines execute as they should. It is after those lines when things become iffy. I don't see the form (reappear) like I normally would when everything else is working. To me, this indicates that the PHP has successfully run. I go to the 'highschool' table but I don't see the value (paymentid) that I am expecting to see. I personally can't think of a single reason why this wouldn't work, but, I am not that experienced in PHP or MySQL so I am open to any help that I can get.
I hope this makes sense without seeing the structure of the tables but if I need to post those, let me know. I've spent a couple hours trying to troubleshoot this problem but with no forward progress.
Thanks!
Assuming this query returns only one row:
$sqldata = mysqli_query($dbcon, $sqlget);
$row = mysqli_fetch_array($sqldata);
$paymentid = $row['paymentid']; // then use $paymentid in the next query
$sqlupdate = "UPDATE highschool SET paymentid = '$paymentid'
WHERE hsgameid = '$selected1'";
if(mysqli_query($dbcon, $sqlupdate)){
echo 'Update successfull';
} else {
echo 'Update query is wrong. The query generated was <br />'.$sqlupdate;
}
try like this,
include('Connection/connect-test.php');
$selected1 = $_POST['selected'];
$sqlupdate = "UPDATE highschool SET paymentid = (select paymentid FROM highschoolpayment WHERE hsgameid = '$selected1') where hsgameid = '$selected1'";
mysqli_query($dbcon, $sqlupdate);
you need to do fetch_assoc(), and while you are at it you should parameterize your query to make it more secure, good practice for the future. here is what your code should look like
$selected1 = $_POST['selected'];
$connect = mysqli_connect("localhost","user","pass","database");//i connect this way to my database
//the first statement that will get your paymentid
$stmt = $connect->prepare("SELECT paymentid FROM highschoolpayment WHERE hsgameid = ?")
mysqli_stmt_bind_param($stmt, 's', $selected1);//'s' is for string, 'i' for int, google rest
$stmt->execute();
$result = $stmt->get_result();
while($row = $result->fetch_assoc()){//it fetches each id
//the second statement that will use the payment id and update the database
$stmt2 = $connect->prepare("UPDATE highschool SET paymentid = ? WHERE hsgameid = ? ;")
mysqli_stmt_bind_param($stmt2, 'ss',$row['paymentid'], $selected1 );//'s' is for string, 'i' for int, google rest
$stmt2->execute();
$stmt2->close();
}
$stmt->close();
I just threw this quickly together, so if anyone sees something wrong don't hesitate to edit it or mark it down if completely wrong, Would rather that.

Check if an user is in a database

I have developed a game with Javascript and when the user finishes it, I must save his record in a database. Here you see the code:
$temp = $_POST['playername']; //username
$text = file_get_contents('names.txt'); //list with all usernames
//this text file contains the names of the players that sent a record.
$con=mysqli_connect("localhost","username","pass","my_mk7vrlist");
if (stripos(strtolower($text), strtolower($temp)) !== false) {
//if the username is in the list, don't create a new record but edit the correct one
mysqli_query($con, "UPDATE `my_mk7vrlist`.`mk7game` SET `record` = '".$_POST['dadate']."' WHERE `mk7game`.`playername` = ".$temp." LIMIT 1 ");
} else {
//The username is not in the list, so this is a new user --> add him in the database
mysqli_query($con, "INSERT INTO `mk7game` (`playername`,`record`,`country`,`timen`) VALUES ('".$_POST['playername']."', '".$_POST['dadate']."', '".$_POST['country']."', '".$_POST['time_e']."')");
file_put_contents("names.txt",$text."\n".$temp);
//update the list with this new name
}
//Close connection
mysqli_close($con);
When I have a new user (the part inside my "else") the code works correctly because I have a new row in my database.
When the username already exists in the list, it means that this player has already sent his record and so I must update the table. By the way I cannot edit the record on the player that has alredy sent the record.
mysqli_query($con, "UPDATE `my_mk7vrlist`.`mk7game` SET `record` = '".$_POST['dadate']."' WHERE `mk7game`.`playername` = ".$temp." LIMIT 1 ");
It looks like this is wrong, and I can't get why. I am pretty new with PHP and MySQL.
Do you have any suggestion?
You're missing quotes around $temp in the UPDATE statement:
mysqli_query($con, "UPDATE `my_mk7vrlist`.`mk7game`
SET `record` = '".$_POST['dadate']."'
WHERE `mk7game`.`playername` = '".$temp."'
^ ^
LIMIT 1 ") or die(mysqli_error($con));
However, it would be better to make use of prepared statements with parameters, rather than inserting strings into the query.
Escape your user input!
$temp = mysqli_real_escape_string($con, $_POST['playername']);
Make sure to stick your mysqli_connect() above that
$select = mysqli_query($con, "SELECT `id` FROM `mk7game` WHERE `playername` = '".$temp."'");
if(mysqli_num_rows($select))
exit("A player with that name already exists");
Whack that in before the UPDATE query, and you should be good to go - obviously, you'll need to edit it to match your table setup

PHP insert into database query

I am trying to insert values into a database table, a row is inserted but blank no values are inserted. Only the order_id which is the primary key with auto increment increase.
php code:
<?php
$user_get = mysql_query("SELECT * FROM users");
while($row_user = mysql_fetch_assoc($user_get)){
if($row_user['username'] == $_SESSION['username']){
$row_user['first_name'] = $res1;
$row_user['last_name'] = $res2;
$store_order ="INSERT INTO oko (user, product) VALUES ('$res1', '$res2')";
mysql_query($store_order);
}
}
?>
Your assignments are backwards. I think you meant to:
$res1 = $row_user['first_name'];
$res2 = $row_user['last_name'];
Don't you mean:
$res1 = $row_user['first_name'];
$res2 = $row_user['last_name'];
You could also update the SELECT to have a WHERE clause that checks $_SESSION['username'].
You could also just do an INSERT/SELECT:
INSERT INTO oko (user, product)
SELECT
first_name, last_name
FROM
users
WHERE
username = '$_SESSION["username"]'
Your code is vulnerable to injection. You should use properly parameterized queries with PDO/mysqli

PHP Query failing, show error?

I have a query on my page that uses a GET variable to pull data from my table...
If I echo my GET var the data is there so im doing something wrong with my query, instead of or die can I show an error in the browser?
// Get USER ID of person
$userID = $_GET['userID'];
// Get persons
$sql = 'SELECT * FROM persons WHERE id = $userID';
$q = $conn->query($sql) or die('failed!');
$sql = "SELECT * FROM persons WHERE id = $userID";
You must use double quotes to use variables inside the query string.
You can also do this:
$sql = "SELECT * FROM persons WHERE id = ".$userID;
What you should do is this (to protect yourself from sql injection):
$safeuid = $conn->prepare($userID);
$sql = "SELECT * FROM persons WHERE id = ".$safeuid;
You can always debug using this at the top of your php page:
ini_set('display_errors',1);
error_reporting(E_ALL);
Have you tried $q = $conn->query($sql) or die($conn->error()); ?
Yes you can, but you should only do it for debugging. Crackers can gain a lot of insight by purposefully feeding bad input and reading the error.
I'm assuming you're using MySQLi; the command is $conn->error(). So your line would be:
$q = $conn->query($sql) or die($conn->error());
Also, what you're doing wrong is you're using single quotes to define $sql. You need to use double quotes to write $userID into the string. So what you want is:
$sql = "SELECT * FROM persons WHERE id = $userID";
or
$sql = 'SELECT * FROM persons WHERE id = ' . $userID;
You need to use double quotes to evaluate variables within the string. That is,
$sql = 'SELECT * FROM persons WHERE id = $userID';
should be
$sql = "SELECT * FROM persons WHERE id = $userID";
Rather than removing the die you should make sure the query is always valid. In other words: validate the userID parameter. $_GET can contain anything the user wants to provide - it could be an array, it could be a string, it could be a string with a malicious payload that can drop your tables. So check it is an integer. If not, return a relevant message to the user.
Not a php expert but you might try:
// Get USER ID of person
$userID = $_GET['userID'];
// Get persons
$sql = 'SELECT * FROM persons WHERE id = $userID';
$q = $conn->query($sql) or die('failed!' . mysql_error());
The error should append to the end of your die message.

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