php decode JSON -> mysql query - php

I'm trying to make query.
I don't know why this php doesn't work.
there is no change in my DB.
are there errors?
<?
$json = file_get_contents('php://input');
$obj = json_decode($json);
$con = mysql_connect("localhost:(port)","ID","PW")
or die('Cannot connect to the DB');
mysql_select_db("DBID",$con);
$row = $obj->{"menusel_row"};
$col = $obj->{"menusel_col"};
$val = $obj->{"menuvalue"};
mysql_query("UPDATE recommend SET $row = '$val' where id = '$col'", $con);
mysql_close($con);
?>

A brief note: you are using short open tags for PHP <?, this feature most probably is disabled on your PHP server, because it is obsolete.
Absence of any output most probably is related to that. Use <?php instead.

Related

Connection is made to the database with php script but no values are returned

I have a successful connection to the database through this php script but it is not returning any values even though it is connected. I am checking for the results on my web browser and it just returns a blank screen. I have used the same script (different queries) to access two other tables in the database and they are both working fine. Here is my code:
<?php
$username = "xx";
$password = "xxx";
$host = "xxxxx";
$database="xxxxx";
$server = mysql_connect($host, $username, $password);
$connection = mysql_select_db($database, $server);
$myquery = "SELECT `AUTHOR`, `In_order` from `authors`";
$query = mysql_query($myquery);
if ( ! $query ) {
echo mysql_error();
die;
}
$data = array();
for ($x = 0; $x < mysql_num_rows($query); $x++) {
$data[] = mysql_fetch_assoc($query);
}
echo json_encode($data);
mysql_close($server);
?>
It is probably some silly mistake that I have over looked but I have been stuck on it for longer than I should! thanks in advance for any feedback
Tried you code locally on some data and it returns everything ok.
I needed to change the select to match my data
So I am 95% sure the problem is in your query / db settings.
I would first check if your columns in database is really called AUTHOR and 'In_order' with the exact capital letters.
MySql names can be case sensitive depending on your db server settings, and this could be the problem
Sidenote: if you can research mysqli and pdo for connecting to DB instead of mysql that is deprecated.
Try this:
$myquery = "SELECT `AUTHOR`, `In_order` from `authors`";
$query = mysql_query($myquery);
$num = mysql_num_rows($query);
var_dump($query);
var_dump($num);
echo mysql_error();
and tell us what it all says.
Edit: okay, so it's 231 rows in your table, as the var_dump($num) says. Now let's try and get them at last, but in a slightly more efficient way:
while ($row = mysql_fetch_assoc($query)) {
$data[] = $row;
}
echo json_encode($data);
I have a feeling that your "for" loop and mysql_fetch_assoc() inside is what plays tricks with you, because both of them use different internal counters.

Generate simple JSON file based on database

Hey I am iOS developer I am trying to create simple JSON output from my website. I found good start link and here is some explanation how to do it.
So I've created accounts.php file and put it to my public_html folder
<?php
include_once("JSON.php");
$json = new Services_JSON();
$link = mysql_pconnect("localhost", "user", "pass") or die("Could not connect");
mysql_select_db("iglobe") or die("Could not select database");
$arr = array();
$rs = mysql_query("SELECT * FROM users");
while($obj = mysql_fetch_object($rs)) {
$arr[] = $obj;
}
Echo $json->encode($arr);
?>
Of course I use my user and password and I pointed my just created database ob my end.
so when I try to request my file so http//mywebsite.com/accounts.php there is no data.
I tried to use google chrome and Postman so it says No response received when I switch to JSON. For HTML there is no info in Postman.
My question how can I test it? even if I use Echo(123) before include_once("JSON.php"); line there is no 123 on html page.
I tried to test PHP with only this code:
<?php
phpinfo();
?>
and it works. I have PHP Version 5.4.32
First of all, simply use PHP's function json_encode($arr). It does exactly what you are asking for and is pretty much included in every version of PHP that I can think of.
Documentation
Also, I am not sure if this is the issue, but you may want to change Echo ==> echo. This is generally convention at the very least.
SUPER IMPORTANT
Finally, DO NOT USE mysql extension. Its is dangerous, may not work correctly, and has security vulnerabilities. Use mysqli or PDO.
Matrosov -
You are very close. Use the json_encode function to output your code via the PHP manual. Also consider using mysqli instead of mysql for your database connection as it has been better support for modern MySQL servers.
http://php.net/manual/en/function.json-encode.php
http://php.net/manual/en/book.mysqli.php
<?php
include_once("JSON.php");
$link = mysqli_connect("localhost", "user", "pass") or die("Could not connect");
$link->mysql_select_db("iglobe") or die("Could not select database");
$arr = array();
$rs = mysql_query("SELECT * FROM users");
while($obj = mysql_fetch_object($rs)) {
$arr[] = $obj;
}
echo json_encode($arr);
?>

Outputting contents of database mysqli

Hi I know this is a little general but its something I cant seem to work out by reading online.
Im trying to connnect to a database using php / mysqli using a wamp server and a database which is local host on php admin.
No matter what I try i keep getting the error Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, boolean given when i try to output the contents of the database.
the code im using is:
if (isset($_POST["submit"]))
{
$con = mysqli_connect("localhost");
if ($con == true)
{
echo "Database connection established";
}
else
{
die("Unable to connect to database");
}
$result = mysqli_query($con,"SELECT *");
while($row = mysqli_fetch_array($result))
{
echo $row['login'];
}
}
I will be good if you have a look at the standard mysqli_connect here
I will dont seem to see where you have selected any data base before attempting to dump it contents.
<?php
//set up basic connection :
$con = mysqli_connect("host","user","passw","db") or die("Error " . mysqli_error($con));
?>
Following this basic standard will also help you know where prob is.
you have to select from table . or mysqli dont know what table are you selecting from.
change this
$result = mysqli_query($con,"SELECT *");
to
$result = mysqli_query($con,"SELECT * FROM table_name ");
table_name is the name of your table
and your connection is tottally wrong.
use this
$con = mysqli_connect("hostname","username","password","database_name");
you have to learn here how to connect and use mysqli

How to connect to a SQLite3 db with PHP

I'm new to SQLite3 and PHP and was wondering whether and how I could connect to a SQLite3 database with PHP.
How would I get the data from the db and would it be possible to output them on a browser screen?
I've been searching the web for a while now, but couldn't find anything.
Thank you.
<?php
$db = new SQLite3('mysqlitedb.db');
$results = $db->query('SELECT bar FROM foo');
while ($row = $results->fetchArray()) {
var_dump($row);
}
?>
Taken from here: PHP: SQLite3::query - Manual
SQLite is enabled by default with PHP. You have to use the built-in class SQLite3 (you will find some examples on this page).
This is the best way I have found and I got it directly from the sqlite website:
<?php
$db = new SQLite3('sqlite3db.db');
$results = $db->query('select * from db');
while ($row = $results->fetchArray()) {
var_dump($row);
}
?>
Also if you're looking to include the php results into html like a table cell or something, go as such:
$results = $db->query('select * from db');
?>
<?php while ($row = $results2->fetchArray()) {?>
<td><h4><?php echo $row['id'];?></h4></td>
<?php } ?>

Why is my php script freezing?

What is causing my php code to freeze? I know it's cause of the while loop, but I have $max_threads--; at the end so it shouldn't do that.
<html>
<head>
<?php
$db = mysql_connect("host","name","pass") or die("Can't connect to host");
mysql_select_db("dbname",$db) or die("Can't connect to DB");
$sql_result = mysql_query("SELECT MAX(Thread) FROM test_posts", $db);
$rs = mysql_fetch_row($sql_result);
$max_threads = $rs[0];
$board = $_GET['board'];
?>
</head>
<body>
<?php
While($max_threads >= 0)
{
$sql_result = mysql_query("SELECT MIN(ID) FROM test_posts WHERE Thread=".$max_threads."", $db);
$rs = mysql_fetch_row($sql_result);
$sql_result = mysql_query("SELECT post FROM test_posts WHERE ID=".$rs[0]."", $db);
$post = mysql_fetch_row($sql_result);
$sql_result = mysql_query("SELECT name FROM test_posts WHERE ID=".$rs[0]."", $db);
$name = mysql_fetch_row($sql_result);
$sql_result = mysql_query("SELECT trip FROM test_posts WHERE ID=".$rs[0]."", $db);
$trip = mysql_fetch_row($sql_result);
if(!empty($post))
echo'<div class="postbox"><h4>'.$name[0].'['.$trip[0].']</h4><hr />' . $post[0] . '<br /><hr />[Reply]</div>';
$max_threads--;
}
?>
</body>
</html>
First, I'd suggest completely getting rid of the extraneous HTML bits. Then, build up your code slowly, line-by-line to see if you can find the offending line. So write a script that just connects to the database and see what happens.
If you find for example that this code...
<?php
$db = mysql_connect("host","name","pass") or die("Can't connect to host");
mysql_select_db("dbname",$db) or die("Can't connect to DB");
?>
...is causing the freeze on its own, then it could easily be a problem with the MySQL server.
However, if the browser itself is crashing, that sounds like an issue with your system rather than something that PHP or MySQL is doing...
Try this 1 SQL query instead of those 1 + (4 * n) queries:
SELECT MIN(ID), post, name, trip FROM test_posts GROUP BY Thread
Maybe a LIMIT 50 (or whatever max # of threads to return) at the end as well, that could be a lot of data.
You can just loop over the results of this query instead of $max_threads and all the extra db calls, via while ($row = mysql_fetch_row($sql_result)) { /* echo(...); */ }.
Not sure that's exactly the same as what you're trying to fetch without knowing more about the data (getting the root post of each thread in a forum?), but it should be pretty close.
(P.S.: if that's a threaded 2ch-style forum deal, I'm not sure that's an ideal db design. A parent-child adjacency list might be better than maintaining a number count for each thread. Just a guess though.)
I'm thinking it's because you're hitting the sql database 4 times per loop. Is there any way you can maybe access it all at once, and then parse the incoming data from there?
$dbsql = 'SELECT * FROM my_database';
$result = mysql_query($dbsql);
while($row = mysql_fetch_array($result)) {
// Parse information here, rather than
// accessing the database for individual variables...
}
Something like that.
Update:
Other than what I've already said (and you've dismissed) all I see are some here & there coding quirks:
This part didn't have a space between echo and the string. The 'hr' element didn't have a starting bracket.
echo '<div class="postbox"><h4>'.$name[0].'['.$trip[0].']</h4><hr>' . $post[0] . '<br /><hr />[Reply]</div>';
'while' Shouldn't be capitalized.
while($max_threads >= 0)
Again, clean code is a good place to start, but that's all I've got, personally. I just recently cleaned up my own site, which was crashing IE (and no other browser), simply because it had too many markup errors. Hope it helps.
Maybe you can scatter calls to this simple function in yer code:
function of($required)
{
$args = func_get_args();
var_dump($args);
ob_flush();
flush();
}
of(__LINE__, $max_threads);
You can also use something like this for your queries:
function mydb_query($query, $db = null)
{
$args = func_get_args();
$result = call_user_func_array('mysql_query', $args);
if (!$result) {
of(array(__FUNCTION__), mysql_error(), $sql);
//return something else?
}
return $result;
}
$result = mydb_query("SELECT post, name, trip FROM test_posts WHERE ID = (SELECT MIN(ID) FROM test_posts WHERE Thread={$max_threads})", $db);
You should use mysqli/PDO/framework with support for prepared statements.
Probably the script is exceeding the maximum server execution time threshold, try this on the top of your file to confirm this:
ini_set('max_execution_time', '180');

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