MSSQL and PHP: Select specific row based on which button is clicked - php

Question

I am making a website for a mock book database using MSSQL where users can search for different books and select particular books that they might like to add to a list of favorites under their account name. The problem I am having is that I have no idea how to differentiate which book selection they want to add to their favorites because I can't figure out how to set the ISBN of the book, which uniquely identifies it, to a php session variable. If anyone can shed some light on this I would appreciate it, have been trying to figure it out all day.
//Set up connection
$connection = mssql_connect("$hostName", "$sqlUsername", "$sqlPassword")
or die("ERROR: selecting database server failed.");
//Select database
mssql_select_db($databaseName, $connection)
or die("ERROR: Selecting database failed");
//Search to run if searching for book title
if(isset($_GET['searchBook'])){
$searchBook = $_GET['searchBook'];
$query = "SELECT BOOK.ISBN, Title, Author, Publisher, NumberOfPages, Language, LocationName, ListPrice FROM BOOK, PRICE, LOCATION WHERE Title LIKE '%$searchBook%' AND BOOK.ISBN = PRICE.ISBN AND PRICE.LocationID = LOCATION.LocationID";
}
//Search to run is searching for a book author
if(isset($_GET['searchAuthor'])){
$searchAuthor = $_GET['searchAuthor'];
$query = "SELECT BOOK.ISBN, Title, Author, Genre, Publisher, NumberOfPages, Language, LocationName, ListPrice FROM BOOK, PRICE, LOCATION WHERE Author LIKE '%$searchAuthor%' AND BOOK.ISBN = PRICE.ISBN AND PRICE.LocationID = LOCATION.LocationID";
}
//Store query result
$query_result = mssql_query($query, $connection)
or die( "ERROR: Query is wrong");
//Set up table to display search results
echo "<form action=\"addFavorite.php\" method=\"POST\" name=\"table\">";
echo "<table border=1 align=\"center\">";
echo "<tr>";
// fetch attribute names
while ($filed = mssql_fetch_field($query_result)) {
echo "<th>".$filed->name."</th>";
}
echo "<th>Favorite</th>";
echo "</tr>";
// fetch table records
while ($line = mssql_fetch_row($query_result)) {
echo "<tr>\n";
foreach ($line as $eachline) {
echo "<td> $eachline </td>";
}
echo "<td><input name=\"".$line['index']."\" type=\"submit\" value=\"Add To Favorites\"></td>";
echo "</tr>\n";
}
echo "</table>";
echo "</form>";
Not sure if this is relevant but the following code is my best attempt at getting the value of ISBN that corresponds to the row of the button being clicked, which doesn't exactly work like I had hope.
//Get the ISBN
$data = mssql_fetch_assoc($query_result);
$ISBN = $data['ISBN'];
echo $ISBN;
Here is the code for my addFavorite.php which is where the form action is set to. This is the file that needs to know what user is adding a book as a favorite AND what book they are adding to that list.
//Set up connection
$connection = mssql_connect("$hostName", "$sqlUsername", "$sqlPassword")
or die("ERROR: selecting database server failed.");
//Select database
mssql_select_db($databaseName, $connection)
or die("ERROR: Selecting database failed");
$User = $_SESSION['userID'];
//Set up query
$query = "INSERT INTO FAVORITES VALUES(\"$User\",\"**I NEED A SESSION VARIABLE OR SOMETHING TO GO HERE\")";
//Store query result
$query_result = mssql_query($query, $connection)
//or die( "ERROR: Query is wrong");
Any help would be much appreciated. I know it's alot of information and if there is anything that doesn't make sense or I have forgotten to provide please let me know. Thanks.
EDIT
I have tried using the BUTTON instead of using INPUT but the value of the button is not setting to anything for some reason.
echo "<form action=\"addFavorite.php\" method=\"POST\" name=\"table\">";
echo "<table border=1 align=\"center\">";
echo "<tr>";
// fetch attribute names
while ($filed = mssql_fetch_field($query_result)) {
echo "<th>".$filed->name."</th>";
}
echo "<th>Favorite</th>";
echo "</tr>";
// fetch table records **PROBLEM IN HERE since $line['ISBN'] returns nothing**
while ($line = mssql_fetch_row($query_result)) {
echo "<tr>\n";
foreach ($line as $eachline) {
echo "<td> $eachline </td>";
}
echo "<td><button name=\"FavoriteButton\" type=\"submit\" value=\"".$line['ISBN']."\">Add To Favorites</button></td>";
echo "</tr>\n";
}
echo "</table>";
echo "</form>";
EDIT 2
Finally got it working, thanks to everyone for helping! Partial code that was problematic posted below in working condition.
echo "<form action=\"addFavorite.php\" method=\"POST\" name=\"table\">";
echo "<table border=1 align=\"center\">";
echo "<tr>";
// fetch attribute names
while ($filed = mssql_fetch_field($query_result)) {
echo "<th>".$filed->name."</th>";
}
echo "<th>Favorite</th>";
echo "</tr>";
// fetch table records
while ($line = mssql_fetch_row($query_result)) {
echo "<tr>\n";
foreach ($line as $eachline) {
echo "<td> $eachline </td>";
}
echo "<td><button name=\"FavoriteButton\" type=\"submit\" value=\"".$line[0]."\">Add To Favorites</button></td>";
echo "</tr>\n";
}
echo "</table>";
echo "</form>";

Answer 1

Use a BUTTON-element instead of the INPUT-element. That way, you can use the 'value'-attribute of this element to pass the correct value.
echo "<td><button name=\"$line['index']\" value=\"$line['ISBN']\" type=\"submit\">Add to favorites</button></td>";
Although I would suggest using AJAX instead of the above approach for this: use the onclick event from a button to execute javascript that calls a seperate php-file and passes the correct ISBN-number. This is then added to the database and your original page should be refreshed or part of the page reloaded.