PHP - Reading And Writing To Database (should Be Simple)

Hi   I come from a desktop (vb.net) background and have used oridinary text files for my databases. I use file locking to prevent other processes from writing to the same file simultaneously.   Now I am moving over the PHP/MySQL - what precautions should I take to stop a simultaneous processes from writing to a table at the same time.?   Do I need to lock the table before writing to it?   Does MySQL deal with this automatically and just block my process until the table becomes free?   (I am talking about a single table here, not multiple dependant tables - I know that is another issue)   Thanks     Nigel

does anyone know how to decode this XML variable value into string values? I also need to know the oposite way: creating variable values into xml. I've tried several code examples but they did filter the requested data.

Code: [Select]
$xml='<?xml version="1.0" encoding="utf-8"?>
<elements>
<text identifier="ed9cdd4c-ae8b-4ecb-bca7-e12a5153bc02">
  <value/>
</text>
<textarea identifier="a77f06fc-1561-453c-a429-8dd05cdc29f5">
  <value><![CDATA[<p style="text-align: justify;">Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>]]></value>
</textarea>
<textarea identifier="1a85a7a6-2aba-4480-925b-6b97d311ee6c">
  <value><![CDATA[<p style="text-align: justify;">Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy  eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed  diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum.  Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor  sit amet.</p>]]></value>
</textarea>
<image identifier="ffcc1c50-8dbd-4115-b463-b43bdcd44a57">
  <file><![CDATA[images/stories/red/cars/autobedrijf.png]]></file>
  <title/>
  <link/>
  <target/>
  <rel/>
  <lightbox_image/>
  <width><![CDATA[250]]></width>
  <height><![CDATA[187]]></height>
</image>
<text identifier="4339a108-f907-4661-9aab-d6f3f00e736e">
  <value><![CDATA[Kramer 5]]></value>
</text>
<text identifier="ea0666d7-51e3-4e52-8617-25e3ad61f8b8">
  <value><![CDATA[6000 RS]]></value>
</text>
<text identifier="90a18889-884b-4d53-a302-4e6e4595efa0">
  <value><![CDATA[Eindhoven]]></value>
</text>
<text identifier="410d72e0-29b3-4a92-b7d7-f01e828b1586">
  <value><![CDATA[APK Pick up and return]]></value>
</text>
<text identifier="45b86f23-e656-4a81-bb8f-84e5ea76f71f">
  <value><![CDATA[15% korting op grote beurt]]></value>
</text>
<text identifier="3dbbe1c6-15d6-4375-9f2f-f0e7287e29f3">
  <value><![CDATA[Gratis opslag zomerbanden]]></value>
</text>
<text identifier="2e878db0-605d-4d58-9806-8e75bced67a4">
  <value><![CDATA[Gratis abonnement of grote beurt]]></value>
</text>
<text identifier="94e3e08f-e008-487b-9cbd-25d108a9705e">
  <value/>
</text>
<text identifier="73e74b73-f509-4de7-91cf-e919d14bdb0b">
  <value/>
</text>
<text identifier="b870164b-fe78-45b0-b840-8ebceb9b9cb6">
  <value><![CDATA[040 123 45 67]]></value>
</text>
<text identifier="8a91aab2-7862-4a04-bd28-07f1ff4acce5">
  <value/>
</text>
<email identifier="3f15b5e4-0dea-4114-a870-1106b85248de">
  <value/>
  <text/>
  <subject/>
  <body/>
</email>
<link identifier="0b3d983e-b2fa-4728-afa0-a0b640fa34dc">
  <value/>
  <text/>
  <target/>
  <custom_title/>
  <rel/>
</link>
<relateditems identifier="7056f1d2-5253-40b6-8efd-d289b10a8c69"/>
<rating identifier="cf6dd846-5774-47aa-8ca7-c1623c06e130">
  <votes><![CDATA[1]]></votes>
  <value><![CDATA[1.0000]]></value>
</rating>
<googlemaps identifier="160bd40a-3e0e-48de-b6cd-56cdcc9db892">
  <location><![CDATA[50.895711,5.955427]]></location>
</googlemaps>
</elements>';

Hi   I have this json file   {"user":"RD32","time":"14:00","type":"staff"}
{"user":"XC12","time":"21:00","type":"management"}
{"user":"YG89","time":"09:00","type":"staff"}   and I want to pull just "staff" from it and output like   user: RD32 time: 14:00 ----- user: YG89 time: 09:00   is that possible?

I have written some code to past information from one page to a diffrent page however all the variables are sent over but they are not writting to the database could anyone help me out please ....

$ud_P_Id = $_POST['ud_P_Id'];
$ud_LastName = $_POST['ud_LastName'];
$ud_FirstName = $_POST['ud_FirstName'];
$ud_GroupCode=$_POST['ud_GroupCode'];
$ud_P_Unit1=$_POST['ud_P_Unit1'];
$ud_P_Unit2=$_POST['ud_P_Unit2'];
$ud_P_Unit3=$_POST['ud_P_Unit3'];
$ud_P_Unit6=$_POST['ud_P_Unit6'];
$ud_P_Unit14=$_POST['ud_P_Unit14'];
$ud_P_Unit20=$_POST['ud_P_Unit20'];
$ud_P_Unit27=$_POST['ud_P_Unit27'];
$ud_P_Unit28=$_POST['ud_P_Unit28'];
$ud_P_Unit42=$_POST['ud_P_Unit42'];
$ud_P_Unit10=$_POST['ud_P_Unit10'];
$ud_P_Unit11=$_POST['ud_P_Unit11'];
$ud_P_Unit12=$_POST['ud_P_Unit12'];
$ud_P_Unit13=$_POST['ud_P_Unit13'];
$ud_P_Unit1454=$_POST['ud_P_Unit1454'];
$ud_P_Unit15=$_POST['ud_P_Unit15'];
$ud_P_Unit16=$_POST['ud_P_Unit16'];
$ud_P_Unit17=$_POST['ud_P_Unit17'];
$ud_P_Unit18=$_POST['ud_P_Unit18'];


$con = mysql_connect('localhost', 'lccstude_progre', '********');
$db= "lccstude_pro";
if (! $con)
die("Couldn't connect to MySQL");
mysql_select_db($db , $con)
or die("Couldn't open $db: ".mysql_error());




mysql_query("UPDATE BTECL31113 SET FirstName='$ud_FirstName' , LastName='$ud_LastName' , GroupCode='$ud_GroupCode' , Unit1='$ud_P_Unit1' , Unit2='$ud_P_Unit2' , Unit3='$ud_P_Unit3' , Unit6='$ud_P_Unit6' , Unit14='$ud_P_Unit14' , Unit20='$ud_P_Unit20' , Unit27='$ud_P_Unit27' , Unit28='$ud_P_Unit28' , Unit42='$ud_P_Unit42' , Unit10='$ud_P_Unit10' , Unit11='$ud_P_Unit11' , Unit12='$ud_P_Unit12' , Unit13='$ud_P_Unit13' , Unit1454='$ud_P_Unit1454' , Unit15='$ud_P_Unit15' , Unit16= $ud_P_Unit16' , Unit17='$ud_P_Unit17' , Unit18='$ud_P_Unit18' WHERE P_Id='$ud_P_Id'");

echo "Record Updated";

mysql_close($con);



Please any help would be great

I'm writing a script that takes user input from a html form and updates the database with the new data. In this example the user is updating the data about the university they attend. The problem with this is, the script to update the database with the new information appears to be not working - the new data is not being added to the database. The SQL queries used in the script work in phpMyadmin, and the variables - $uni and $username - contain the data the correct data. This has me stumped, could someone look over this for me please and tell me what is going wrong here.

Code: [Select]
<?php

  include 'connect.php';
  
  session_start();
  $_SESSION['username']; 
  
  if(!(isset($_SESSION['login']) && $_SESSION['login']!= " ")){
       header("Location: login.php");
   }
   
  $username = $_SESSION['username'];
  $tablename = 'usr_test';
  

  $uni = $_POST['uni'];
  
  $uni = stripslashes($uni);
  $uni = mysql_real_escape_string($uni);
  $uni = trim($uni);

if(isset($uni))
{  
   $username = $_SESSION['username'];
   $loc = mysql_query("SELECT * FROM usr_test WHERE usr = '$username'");

   if (mysql_num_rows($loc) == 0)
   header("Location:notlogged.php");
   
   else 

   {

    extract(mysql_fetch_array($loc));

    mysql_query("UPDATE usr_test SET uni = ('$uni') WHERE usr = '$username'") or die (mysql_error());
    header("Location:profile.php");

   }
    }

  ?>

Hi everyone,

Im trying to serialize the values of checked checkboxes, save them to a database, then on another page retrieve the value from the database, unserialize it, and then write each checkbox value to the database individually.

Using the following test code I'm able to serialize the checkbox values, and then unserialize them and echo them out fine, however im unsure how to separate them and save them individually into the database.


$string = implode($_POST['checkbox']);
$test = serialize($string);
$test2 = unserialize($test);
echo $test2;

<?php $i = 0; ?>
<?php while ($row = mysql_fetch_assoc($query)) { ?>

<tr>
    

<td><input type="checkbox" name="<?php echo "checkbox[$i]"; ?>" value="<?php echo $row['test']; ?>" /></td>
    </tr>
<?php $i++; } ?>


Any ideas?
Thanks

I have a normalized database in the form of

Code: [Select]
ID   user_id     key           value
1    3           first_name    Brian
2    3           last_name     Tardy
3    4           first_name    John
4    4           last_name     Wilson

What is the fastest way to capture these values within php? I want to perform a SELECT to catch the values for every user as

Code: [Select]
$result=mysql_query("SELECT * FROM users_data WHERE user_id = '$id'");
while($row=mysql_fetch_array($result)) {

here we process all data for a given user
and write it to text file as a single line

}
Since it is a long list (100K users with about 10M of rows in user_data), I am looking for the fastest and most reliable way to scan all the database.
?>

As per the client requirement he wants to read words from a file and want to insert them in database  one by one . ie a confirmation is required whether he wants to insert is or not. I have developed the thing but the problem is when i am retrieving the words it asks for all the words. i will show u wat the problem is. My main query is i want to pause the exectution until user's input.

Code: [Select]
<script type="text/javascript" src="jquery.js"></script>
<script type"text/javascript">
function show() {
document.getElementById('form#submit').fadeIn();
alert("Abhinav");
}
$(document).ready(function(){
$("form#submit").submit(function() {
// we want to store the values from the form input box, then send via ajax below
var word    = $('#word').attr('value');
var synonym     = $('#synonym').attr('value');

$.ajax({
type: "POST",
url: "ajax.php",
data: "word="+ word + "&synonym=" + synonym,
success: function(){
$('form#submit').hide();
//$('form#submit :input').val("");
$('div.success').fadeIn();
}
});
return false;
});
});
</script>

<?php 
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
@$word="";
@$c="";
while (!feof($file))
{
  $c=fgetc($file);
if(strcmp($c," ")==0)
{ echo "".
 
"<form id='submit' method='post' name='submit' action='' >".  
        "<fieldset>  ".
            "<legend>Enter Information</legend>  ".
"            <label for='word'>Word:</label>  ".
"<input id='word' class='text' name='word' size='20' type='text' value='$word' >  ".
"            <label for='Synonym'>Synonym:</label>  ".
"<input id='synonym' class='text' name='synonym' size='20' type='text'>  ".
"            <button class='button positive' type='submit'>  Add Client </button>  ".
   " </fieldset>  ".
   " </form>  ".
"<div class='success' style='display:none;'>Client has been added.</div>  ".
"</div>";
 
$word="";
}
else
$word=$word.$c;
}
fclose($file);

?>



Now what i want is after user clicks add client then only next insertion box must be shown. please check the attached image to see the output. Guys pls help me over this. Thnx in advance

Where is the best to store the list of categories and menu? Obviously it is better to reduce mysql queries. From a plain list in file, we can create desirable list (menu) from an array. This is quite faster (though SELECT from an indexed table is fast too; but I do know if it is as fast as reading from a php file). Any idea how to code this to create the menu faster ?

Is there a simple way getting PHP to open a single file and write to a specific line?

Like:
fwrite (line = 102) {"bla bla bla"};
fclose;

I'm trying to learn how to code the proper way.

There's a few things im worried about,but overall im worried about clogging up the server.  so what should i keep in mind while coding, to avoid this?

I'm thinking, keep insert and update to a minimum?  as in, when possible, use session to keep track of data until i absolutly have to add that data to a database? is that a correct thought?

what about once the data is in the database, how much trouble is it to ask for the selected data inside a database?  should i be worried about overdoing request of data from databases?   

on the other hand, should i be worried about having too many sessions travelling around with a user.  why?

Im just asking to get a better feel for how to do things the proper way, i would hate to have a website built, only to find out that what i built is only a bat, that would bash the hell out of a server i wanted to put it on.

I have a very simple piece of code to create a grid based gallery. The thumbnails are loaded from a single directory and are name 1.jpg... 2.jpg... 3.jpg etc

At the moment the images appear to be loaded in randomly. I want them to load in numerically in terms of their filename. I know I may need to use 'sort' or 'natsort' but where in the code?

Thanks for any help you can give me

Code: [Select]
<?

$images = "Images/Bag Thumbs/"; # Location of small versions

$big    = "ruxxwomens.php?id="; # Location of big versions (assumed to be a subdir of above)

$cols   = 4; # Number of columns to display

if ($handle = opendir($images)) {
   while (false !== ($file = readdir($handle))) {
       if ($file != "." && $file != ".." && $file != rtrim($big,"/")) {
          $files[] = $file;
       }
   }
   closedir($handle);
}



$colCtr = 0;
echo '<table width="800" cellspacing="0" cellpadding="0" border="0"><tr>';
foreach($files as $file)
{
  if($colCtr %$cols == 0)

    echo '</tr><tr>';

  echo '<td align="center"><a href="' . $big . $file . '"><img src="' . $images . $file . '" cellspacing="0" cellpadding="0" border="0"></a></td>';

  $colCtr++;
}
echo '</table>' . "\r\n";

?>

Hello,
Five images will be displayed inside a division.
There will be a previous and next button/link.
If someone click the next button the next image will be added in that div and the first image will be gone from that div.
The previous button/link will do the same thing.

Is it possible with php?
I am confused if it's a javascript or ajax question.

Thanks.

i have enters some data using form which submit data in sql table1 like this,

Fields name in table -->>         id   First name     Lastname    Date   
data saved           -->>              1  user                1               2011-05-10
                                               2  user                2               2011-05-11
                                               3  user                3               2011-05-12

now i dont want to duplicate date in database let say while inserting data using form,

Firstname :  ____________
Lasename :  ____________
Date         :  ____________ (i dont want this date to b save if the date alredy exist in database,
                                          it should prompt user "Date already exist and to edit click here
                                         (this will be the link to that date which is already exist so that we can edit) " )

                                SAVE


i user  files ,       form.php ,   insert.php(so insert values in database) ,
so tell me what function should i use to solve my problem....