Problem with updating form

amar3d

Hi, i have this form that i use to update data on a mysql db. The problem i'm having is the form only lets me update record 1 and no others and i've been trying to find a way to fix it but as yet have been unsuccesful. does anyone know what i can do so that if i wanted to update eg record number 5 i could? below is the code, many thanks in advance...i'm still very new at this

<html><head><title>DVD file</title></head>
<body>
<?
$dvd_id='';
$dvd_id=print_r("$dvd_id");

$db = mysql_connect("localhost","username");
$link = mysql_select_db("test",$db);

$result=mysql_query(" SELECT * FROM dvds WHERE dvd_id='$dvd_id'");

$num=mysql_num_rows($result);
$i=0;
while ($i < $num) {
$dvd_name=mysql_result($result,$i,"dvd_name");
$dvd_price=mysql_result($result,$i,"dvd_price");
$genre=mysql_result($result,$i,"genre");
$release_date=mysql_result($result,$i,"release_date");
$information=mysql_result($result,$i,"information");
?>

<tr> <td align=right>DVD Price</td>

<td><input type="text" name="dvd_price" value="<? echo"$dvd_price" ?>"></td>

</tr>

<tr>
<td align=right>Release Date</td>

<td><input type="text" name="release_date" value="<? echo"$release_date" ?>"></td>
</tr>
<tr> <td align=right>Genre</td>
<td><input type="text" name="genre" value="<? echo"$genre" ?>"></td>

</tr>
<tr>

<td align=right>Information </td>

<td><input type="text" name="information" value="<? echo"$information" ?>"></textarea></td></tr>

devinemke

the code you posted actually does not update anything. there is no UPDATE query, only a SELECT query.

travelbuff

Hi Amar3:

Ok, I don't mean to be rude, but there are a number of errors in the code you posted, and I am not sure exactly what you are trying to do. What is the purpose of this script?

You are setting $dvd_id to '' (NULL) and then selecting all rows in the DB where dvd_id is NULL.
Your while loop doesn't need a counter ($i) and you should be using mysql_fetch_assoc:
```
while ($row=mysql_fetch_assoc($result) {
$dvd_name = $row[dvd_name];
$dvd_price = $row[dvd_price]; 
//etc
}  
```
or, you could just refer to the variables as $row[column] throughout the loop.

Hope that points you in the right direction.

amar3d

Hi mark, Thanks for the reply....basically the point of the script is to update a DVD file, so for example if the price of the DVD were to change the user can enter the DVD's ID which would bring its details up in a form from which they can update the details.

The problem I am having is trying to set $dvd_id to something....for some reason everytime i set it to an ID it says unidentified index,
i need a way for the form to askthe user to enter the DVD_id they want to update and then producing that record for them to update. I am a complete novice at this so if u could help in anyway that would be great

travelbuff

What is your table structure?

I would probably do this as follows:
1. create a summary page that has all of that users DVD entries with the basic info.
2. have a link that uses $GET to communicate the ID of the record you want to modify
3. build the form to use $POST to communicate the id

So, in short:

 
if ($_GET[action] == "modify") && (isset($_GET[dvd_id])) {
  //if this statement is true, we know that the user has clicked a link to modify the entry
   SELECT * FROM dvds WHERE dvd_id = '$_GET[dvd_id]'; 
   //display the form to modify the entry
} //end if ($_GET[action] == "modify") && (isset($_GET[dvd_id]))

if ($_POST[action] == "update") && (isset($_POST[dvd_id])) {
  //we have a modified submission to process
  INSERT INTO dvds VALUES dvd_price = '$_POST[dvd_price]', dvd_name = '$_POST[dvd_name]' 
WHERE dvd_id = '$_POST[dvd_id]' AND user_id = '$_SESSION[user_id]' LIMIT 1;
} //end  ($_POST[action] == "update") && (isset($_POST[dvd_id]) 

//select all of this users records
SELECT * FROM dvds WHERE user_id = '$_SESSION[user_id]';
//or however you are tracking the user
  //build a table showing the summary info, inside a while loop
   $modify_link = "<a href = \"$_SERVER[PHP_SELF]?dvd_id=$id\"> Modify This Entry</a>";

Obviously, that is not ready to go code, it is meant to point you in the right direction. If what I am saying doesn't make any sense to you, please find a tutorial on the topic.

amar3d

Thanks Mate thats great stuff......Cheers for the help, i have an idea of what i now need to do