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PHP - Use Php To See If A Mysql Record Exists - Return Only True Or False
Hey Everyone, I want to start out by saying thanks in advance for reading this. Since I started working with the XAMPP package this community has been a great resource, though this is my first post. most of my work has been modifying existing stuff in our network, this is my first project from scratch.
I am working on an access control project where I am storing site names and RFID tags in a table, and using PHP to check for existing records. Basically, I want to submit 2 credentials from a host (site and RFID), check if they exist together in the table, if so return TRUE or 1, if not return FALSE or 0. I am new to both PHP and MySQL (although I took a course years ago) so I am looking here for help. On this server I have XAMPP installed and everything I need running. I have a table and created a few records for testing. My current trouble is getting PHP to return the proper values for the SQL query. The SQL query works fine, I think - it returns the number of rows that match and that record. I'm not sure this is the result I need to be able to deal with the way I want. Using other resources my current PHP statement looks like this: Code: [Select] if(mysql_num_rows(mysql_query("SELECT * FROM `users` WHERE 'site_name' LIKE 'berland' AND 'card_id' LIKE '290093C84E' LIMIT 0 , 30"))>0){echo '1';} else {echo '0';} So, my table has the entry as noted in this query above. Final one will be dynamic where the host will be sending those values - I will likely need help with that as well, but small steps first.;-) Anyway, I was playing around with the end statement >0{echo '1';} but wasn't able to make it do what I want. Any help is appreciated. Thank you. Aaron Similar TutorialsJust a silly question. I've been using 1 and 0 to tell if something is true or false, such as if a feature is enabled or not. I see that some use the words true and false. Is there a proper way or is either way correct? Thanks! I am trying to take all the information from $results and input it into a text file, sometimes we get duplicates in $results so I want to check the text file for the entry before writing it in so we don't get duplicates in the text file. However inarray keeps returning false, even when I echo out the two arrays and they match? Code: [Select] $myfile = "complete.txt"; foreach ($results['info'] as $data) { $output=$fields['firstname']."|".$record['lastname']."|".$record['address']."|".$record['number']."\n"; $handle = fopen($myfile, "r"); $contents = fread($handle, filesize($myfile)); fclose($handle); $list = array(); $list = explode("\n",$contents); $list = array_map("trim", $list); $current = $output; echo in_array($current,$list) ? $current.' exists' : $current.' does not exist'; if (in_array($current,$list)) { print "duplicate"; } else { if($file=fopen($myfile, "a")) { //open file for writing fwrite($file, $output); //write to file } } } i keep seeing people use this kind of code but i cant find any document or help web pages on it. im sure there is but i done know what to call it. i would really like to learn more about it for example Code: [Select] $lang = isset($_GET['lang']) ? (int)$_GET['lang'] : 1; or Code: [Select] return !empty($result_array) ? array_shift($result_array) : false; I have been trying to write code that deletes a book from a database if the user provides a BookName, and the corresponding DeletionCode. I then want to provide the user with feedback, telling the user whether they have deleted a book, that is they have provided a deletion code and a book name, or whether they have not deleted a book, because they have entered the wrong bookname or book ID. I thought this code would work, but it seems that the $result variable is always set as TRUE, no matter whether the code has deleted a row or not. What have i done wrong? $result = mysql_query("DELETE FROM books WHERE BookName = '$_POST[BookName]' && DeletionCode = '$_POST[Deletioncode]'"); if(!$result){ die('Invalid query: ' . mysql_error()); } else echo "delete book"; Ok I guess this is more a algorithm problem than a php problem, but still I hope someone can help me. I'm trying to write some code that starting from two arrays containing observed and expected values will calculate true and false positive and negative rates of a certain event. Let's say I have 30 events and 5 of them are really red while 25 are blue. (each event is identified by an unique id i.e. number) An observer is required to evaluate the 30 events and answer if they are red or blue, their answer (only if blue if stored in the observed array - in the form of a position id) So in the end I have one array that has the observed red events i.e. 4 56 78 44 90 and the expected array with the actual red events i.e. 4 78 33 34 In this case my true positive would be 2 (4 and 78 that are both in the observed and the expected), my false positive would be 3 (observed but not expected), my false negative 2 (expected but not observed) and my true negative 23 (not expected and not observed, obtained substracting the previous three from the total number of events) How can I calculate this four values using PHP, I thought it was easier but as I started to program it I realized I didn't know where to go Thanks to all! MySQL cannot store Boolean values and thus I use 0/1. Is there much benefit to cast them as Boolean immediately after querying the database, do whatever PHP processing is required, and then convert them back to 0/1 before writing to the database? One benefit is I can type declare my arguments, but I am debating whether it is worth it. Thanks Hi guys! I'm new to PHP and I'm using Drupal and there's a function that one block will be called if PHP scripts returns value TRUE. Now I want my "Search" to only show at ALL THE other pages but not index. With the code: if (Url::exists('http://www.example.com')) I get my Search function to return TRUE so it will be showed on index page only, but not on any other pages!! So I kinda need this on reverse - how do I get a TRUE value for something that excists? In this case it would be www.example.com, or if anyone else has any other ideas I would be very thankful! Hello, I want to check when adding a new user, that if there are 2 records that has the same recruiter id, it's should give an error, if less, than it makes him complete the registration Also check if the National ID number is not assigned to another user, so if there is a record that has it, it should give and error, if it's unavailable, it should let him complete the registration here is my code register.html Code: [Select] <html> <form action="post.php" method="post"> <table> <tr><td>First Name: <input type="text" name="fname" /></td></tr> <tr><td>Middle Name: <input type="text" name="mname" /></td></tr> <tr><td>Last Name: <input type="text" name="lname" /></td></tr> <tr><td>Mobile: <input type="text" name="mobile" /></td></tr> <tr><td>Telephone: <input type="text" name="tel" /></td></tr> <tr><td>Address: <input type="text" name="address" /></td></tr> <tr><td>Job Title: <input type="text" name="job" /></td></tr> <tr><td>Company: <input type="text" name="company" /></td></tr> <tr><td>National ID Number: <input type="text" name="nid" /></td></tr> <tr><td>Recruiter ID: <input type="text" name="recruiteris" /></td></tr> <tr><td>Email: <input type="text" name="email" /></td></tr> <tr><td>Password: <input type="password" name="password" /></td></tr> <tr><td>Type: <input type="text" name="type" /></td></tr> <tr><td><input type="submit" /></td></tr> </table> </form></html> post.php Code: [Select] <?php $sql="INSERT INTO users (id,fname, mname, lname, mobile, tel, address, job, company, nid, recruiteris, email, password, type) VALUES ('','$_POST[fname]','$_POST[mname]','$_POST[lname]','$_POST[mobile]','$_POST[tel]','$_POST[address]','$_POST[job]','$_POST[company]','$_POST[nid]','$_POST[recruiteris]','$_POST[email]','$_POST[password]','$_POST[type]')"; if (!mysql_query($sql,$con)) { die('Error: ' . mysql_error()); } echo "1 record added"; echo "<br />"; echo "<a href='http://waw-eg.com/admin/register.html'>Add More Client? Click Here</a><br/>"; echo "<a href='http://waw-eg.com/admin/Users.php'>View Users Click Here</a>"; mysql_close($con) ?> Hi, I am trying to update the status of the record. I don't want to insert the record if not exists. I just want to know the update is success or not. I tried using affected_rows but it returns 0 if the existing status is same as the new status or if no record exists. Please help. Hi, I just want to know how to check if a row/record already exists for a given table, but this code gives me message in browser: Warning: mysql_num_rows() expects parameter 1 to be resource, boolean given in myTest.php This is the the snippet I am running: Code: [Select] <?php $connxn=mysql_connect("localhost","root"); $db=mysql_select_db("siliconvalley"); $toyNodePath="#document/siliconValleyHELLO"; $queryA=mysql_query("SElECT FROM pathexpress (path_express) WHERE path_express='$toyNodePath'");//make sure AT MOST ONE ROW EXISTS!! if(mysql_num_rows($queryA)==1) print "ALREADY IN table pathexpress!"; else { mysql_query("INSERT INTO pathexpress (path_express) VALUES ('$toyNodePath')"); print "ADDED $toyNodePath to table pathexpress!"; } ?> Please, any help is greatly appreciated! Pehaps this is kidstuff but i'm a kid at heart. I have only 1 form field on a form User enters a special code in the form. Once submitted the form is queried against a mysql database to see if the code exists. If code does not exist it must be reentered. If code exists then redirected. basically its like "get to the next page if you have the code" thanks I am trying to get this query correct. I want to insert a record into the database upon form submission but only if the record does not already exist. If the record exists, then I want it to be updated in the database.
What is happening: Upon form submit, a new record is entered into the database every time. Note: The contact_id column is both primary key and unique in my database. Here is my code:
if($_POST['submit']){
$con=mysqli_connect("localhost","username","password","database_name");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
$org = mysql_real_escape_string($_POST['organization']);
$namefirst = mysql_real_escape_string($_POST['firstName']);
$namelast = mysql_real_escape_string($_POST['lastName']);
$emailaddy = mysql_real_escape_string($_POST['email']);
$phonenum = mysql_real_escape_string($_POST['phone']);
$appquestion = mysql_real_escape_string($_POST['appquestion']);
$banner = mysql_real_escape_string($_POST['banner']);
$bulletin = mysql_real_escape_string($_POST['bulletin']);
$giveaway = mysql_real_escape_string($_POST['giveaway']);
$app = mysql_real_escape_string($_POST['app']);
$tshirt = mysql_real_escape_string($_POST['tshirt']);
$tshirtp = mysql_real_escape_string($_POST['tshirtp']);
$print = mysql_real_escape_string($_POST['print']);
$party = mysql_real_escape_string($_POST['party']);
$orgnotes = mysql_real_escape_string($_POST['notes']);
$sql="INSERT INTO database_name (contact_id, first_name, last_name, email_address, phone_number, org, appquestion, banner, bulletin, giveaway, app, tshirt, promised_tee, print, party, org_notes)
VALUES
('','$namefirst','$namelast','$emailaddy','$phonenum','$churchorg','$appquestion','$banner','$bulletin','$giveaway','$app','$tshirt','$tshirtp','$print','$party','$orgnotes')
ON DUPLICATE KEY UPDATE first_name = '$namefirst', last_name = '$namelast', email_address = '$emailaddy', phone_number = '$phonenum', org = '$org', appquestion = '$appquestion', banner = '$banner', bulletin = '$bulletin', giveaway = '$giveaway', app = '$app', tshirt = '$tshirt', promised_tee = '$tshirtp', print = '$print', party = '$party', org_notes = '$orgnotes'" ;
if (!mysqli_query($con,$sql))
{
die('Error: ' . mysqli_error($con));
}
echo "1 record added";
mysqli_close($con);
}
From everything I have read, I need to use ON DUPLICATE KEY UPDATE to replace the old information with new information in the database upon form submission. While the insert part of my code is working, the portion with ON DUPLICATE KEY UPDATE is not working.
Why might this portion of the code not be working? Is there a better way to insert else update the information?
Thank you for any help or guidance you can give me! I've been working on this concept for three days and have read a ton of information about it, but am still not able to get it to work.
I have a web server which contains a public site and a private site. I want to be able to test for public or private using the page title and return the appropriate header which contains a different banner, css etc. Firstly - the syntax below seems to be incorrect because it doesnt work correctly. More importantly how do I add all the values to an array and than iterate through it to check for a matching page title? Code: [Select] public function publicSite() { if ($this->getTitle()== 'Home' || 'About Us'||'Registration' || 'Sitemap' || 'Contact Us' || 'Useful Links' || 'Feedback') { return true; } return false; } Then later on I would have: Code: [Select] if ($this->publicSite()) { require($ROOT.'interface/pages/publicheader.php'); } else { require($ROOT.'interface/pages/privateheader.php'); } Thanks heaps! Say a script has ignore_user_abort(true); set. If the user aborts the connection and print is called, the buffer doesn't get written anywhere. So shouldn't print() return false in this case? To clarify, I know it doesn't, but shouldn't it? If not, why not? I am looking to accomplish the following but have been hitting a brick wall: * User enters a single keyword into a text field, and conducts a search keyword search. * The results are pulled from the campusbooks.com API(API docs attached) * result are then output in <div> class and includes all the book details and its corresponding url./img etc I'm trying to simplify this process but I continue to receive syntax errors. A step by step practical explanation would do me justice! soo i get info from a form and i want to search for it in my db .. if i find user_name AND user_password the $result returns true .. otherwise false .. <?php require_once("../includes/connection.php"); ?> <?php $user_name=$_POST["user_name"]; $user_password=$_POST["user_password"]; ?> <?php $query = "SELECT * FROM users WHERE '{$user_name}' = user_name AND '{$user_password}'= user_password "; $result = mysql_query($query,$connection); if($result==false){ redirect("../index.php");} elseif($result==true){ redirect("../welcome.php"); } ?> <?php //close connection! mysql_close($connection); ?> but the problem is that it always returns TRUE !!!! whats the problem here exactly ??? Hi all, I have the following mysql delete query that essentially deletes a row from two seperate tables "messages" and "messages2" where the id is equal to that in both of the tables. The problem I am getting (for obvious reasons) is that it will only delete from the table, if it indeed exists in both tables. Here is the query: Code: [Select] DELETE FROM messages,messages2 USING messages,messages2 WHERE messages.id = messages2.id AND messages.id = ?; How would I go about setting it so that the query always deletes from table "messages" and only deletes from "messages2" when a corresponding id exists? I think it would involve an IF EXISTS clause, but I am not sure on this, or indeed how to implement it. Thanks in advance guys Dan The Script:
<form method="post" action="<?php echo $_SERVER['PHP_SELF'] ?>">
<input type="text" name="hashtags" />
<input type="submit" name="submit" />
</form>
<?php
if(isset($_POST['submit'])){
$hashtags = explode(", ", $_POST['hashtags']);
// Prints e.g.: Array ( [0] => #tag1 [1] => #tag2 [2] => #tag3 [3] => #tag4 )
print_r($hashtags);
}
?>
This gets inserted into the input field:
#tag1, #tag2, #tag3, #tag4I am looking to check if any of the hashtags inside the array already exist in the database, if it does not exists it should create the new ones in the table. I know how to do this if all do not exists in the array and then it goes over to the MySQL query and inserts all of them. My Question Is: How to insert only the ones which do not exists out of the array, so the ones which do exists do not get inserted again into the table? Edited by glassfish, 14 October 2014 - 10:15 AM. Hi, I am creating a temporary table. I need to check if the table already exists or not. If exists, I have to use the existing data else have to create a new temporary table. I can use 'Create If Not Exists'. How practical is this query? any issues with the performance? If the table exists it will be a huge data, I don't want to loose that data because recreating is an un-necessary load on the database. Say you have three tables like this...
STUDENTS (studentid, name)
CLASSES (studentid, classname)
GRADES (studentid, grade)
And not all students have grades yet. If you're doing a mysql query like below, is there anything you can add to the statement to check if a grade exists for each student? So that if while lopping through the results of the main query, I can easily do something with the students who don't yet have a grade yet (like maybe mark their names in red).
I can do this by putting a whole separate mysql query inside the looping of the main query, but that seems terribly inefficient to call the database again for EVERY student.
$sql = "SELECT * FROM students, classes, grades
WHERE students.studentid = classes.studentid
ORDER BY students.lastname";
$info= mysqli_query($connection, $sql);
if (!$info) {
die("Database query failed: " . mysqli_error());
} else {
//code
}
Thanks!
Greg
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