Website search functionality with PHP - php

Question

I'm a beginner and I try to make an agriculture application, to gain some experience, and to try something advanced. But I can't figure out how to make searches within my application. I have:
- 4 select html elements
- 5 search boxes
For space reasons, I'll write just 3/14 columns for the html elements.
HTML code:
<form>
<!-- makes the global filter based on all the data from db -->
<select id="select1" name="select1" onchange="this.form.submit()">
<option value="">Select</option>
<option value="code">Code</option>
<option value="land">Land</option>
<option value="name">Name</option>
</select><br/>
<!-- makes a filter for a html column, based on a db column -->
<select id="select2" name="select2" onchange="this.form.submit()">
<option value="">All parcels</option>
<option value="P1">P1</option>
<option value="P2">P2</option>
<option value="P3">P3</option>
</select>
<!-- search boxes to filter 5 html columns -->
<input type="search" id="search1" name="search2">
<input type="search" id="search2" name="search2">
<input type="search" id="search3" name="search3">
<input type="search" id="search4" name="search4">
<!-- same as the previous select menu, just this is for another html column -->
<select id="select3" name="select3" onchange="this.form.submit()">
<option value="">Select</option>
<option value="MO">MO</option>
<option value="MA">MA</option>
<option value="ME">ME</option>
</select>
<!-- the 5th search box -->
<input type="search" id="search5" name="search5">
<!-- renders the data from db according to the selections made by the user or search terms -->
<table id="table" class="display" cellspacing="0" width="100%">
<tr>
<th id="code">Code</th>
<th id="land">Land</th>
<th id="name">Name</th>
</tr>
<tr>
<?php
require 'config.php'; # login to database
# ---- QUERY ----
?>
</tr>
</table>
<!-- this displays in the page as many rows as the user selects -->
<select name="select4" id="select4" onchange="this.form.submit()">
<option value="">Select</option>
<option value="1">1</option>
<option value="5">5</option>
<option value="10">10</option>
</select>
</form>
PHP code: I just put this block of code instead of "# ---- QUERY ----" from above, to populate the html columns within the page:
if(isset($_POST['select1'])){
$select1 = $_POST['select1'];
switch($select1){
case 'code':
$stmt = $db->query("SELECT * FROM users WHERE `code`='code'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
break; # some more cases follows
} # end switch($select1)
} # end if(isset($_POST['select1']))
elseif(isset($_POST['select2'])){
$select2 = $_POST['select2'];
switch($select2){
case P1:
$stmt = $db->query("SELECT * FROM users WHERE `parcel` LIKE '%P1%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
break; # some more cases here
} # end switch($select2)
} # end if(isset$_POST['select2'])
elseif(isset($_POST['search1'])){
$search1 = $_POST['search1'];
$stmt = $db->query("SELECT * FROM users WHERE `name` LIKE '%search1%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
} # end elseif(isset($_POST['search1']))
elseif(isset($_POST['search2'])){
$search2 = $_POST['search2'];
$stmt = $db->query("SELECT * FROM users WHERE `cont_ref_a` LIKE '%search2%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
} # end elseif(isset($_POST['search2']))
elseif(isset($_POST['search3'])){
$search3 = $_POST['search3'];
$stmt = $db->query("SELECT * FROM users WHERE `owner` LIKE '%search3%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
} # end elseif(isset($_POST['search3']))
elseif(isset($_POST['search4'])){
$search4 = $_POST['search4'];
$stmt = $db->query("SELECT * FROM users WHERE `block` LIKE '%search4%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
} # end elseif(isset($_POST['search4']))
elseif(isset($_POST['select3'])){
$select3 = $_POST['select3'];
switch($select3){
case 'T1':
$stmt = $db->query("SELECT * FROM users WHERE `zone`='T1'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr> <?php
}
break; # end case 'T1', more cases follows
} # end switch($select3)
} # end elseif(isset($_POST['select3']))
elseif (isset($_POST['search5'])){
$search5 = $_POST['search5'];
$stmt = $db->query("SELECT * FROM users WHERE `s_a` LIKE '%search5%'");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr><?php
}
} # end elseif(isset($_POST['search5']))
elseif(isset($_POST['select1'])){
$select1 = $_POST['select1'];
switch($select1){
case 'code':
$stmt = $db->query("SELECT * FROM users");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
</tr><?php
}
break; # end case 'code', more cases follows
} # end switch($select1)
} # end elseif(isset($_POST[select1]))
elseif(isset($_POST['select4'])){
$select4 = $_POST['select4'];
switch($select4){
case 1:
$stmt = $db->query("SELECT * FROM users LIMIT 1");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr><?php
}
break; # end case 1, more cases follows
} # end switch($select4)
} # end elseif(isset($_POST['select4'])))
else { # if noone of the select menus or search boxes where filled, then just render all the data from db to the page
$stmt = $db->query("SELECT * FROM users");
while($row = $stmt->fetch_assoc()){ ?>
<tr class="action">
<td id="td"><?php echo $row['code'];?></td>
<td id="td"><?php echo $row['land'];?></td>
<td id="td2"><?php echo $row['name'];?></td>
</tr><?php
}
} # end php script
Sorry for this post beeing so long, but I tried to express as better as I can. The problem is that when I select one option from a select menu, or I enter a term to search, nothing is displayed. I don't care for now if something is missing in my code when comes about security, I just want to make this app work. Any help? Thanks a lot!
LE: I finally found the fix for my problem (and I will write it here so that any other persons that will search for this type of problems, to have an answer (I'll write a trivial example)):
For search-boxes:
<form action="" method="post">
<input type="search" name="search1" onchange="this.form.submit()">
<table>
<tr>
<th>First Name</th>
<th>Last Name</th>
</tr><?php
if(isset($_POST['search1'])){
$search1 = $_POST['search1'];
if(!empty($_POST['search1'])){
$sql = "SELECT * FROM tblName WHERE fname LIKE '%$search1%'";
$stmt = $db->query($sql);
while($row = $stmt->fetch_assoc()){ ?>
<tr>
<td><?php echo $row['fname'];?></td>
<td><?php echo $row['lname'];?></td>
</tr><?php
}
}
}
else {
$sql = "SELECT * FROM tblName";
$stmt = $db->query($sql);
while($row = $stmt->fetch_assoc()){ ?>
<tr>
<td><?php echo $row['fname'];?></td>
<td><?php echo $row['lname'];?></td>
</tr><?php
}
} ?>
</table>
</form>
For select-menus:
<form action="" method="post">
<select name="select1" onchange="this.form.submit()">
<option value="">Select</option>
<option value="fname">First Name</option>
<option value="lname">Last Name</option>
</select>
<table>
<tr>
<th>First Name</th>
<th>Last Name</th>
</tr><?php
if(isset($_POST['select1'])){
$select1 = $_POST['select1'];
if(!empty($_POST['select1'])){
switch($select1){
case 'fname':
$stmt = $db->query("SELECT * FROM users");
while($row = $stmt->fetch_assoc()){ ?>
<tr>
<td><?php echo $row['fname'];?></td>
</tr><?php
}
break;
case 'lname':
$stmt = $db->query("SELECT * FROM users");
while($row = $stmt->fetch_assoc()){ ?>
<tr>
<td><?php echo $row['lname'];?></td>
</tr><?php
}
break;
}
}
}
else {
$stmt = $db->query("SELECT * FROM users");
while($row = $stmt->fetch_assoc()){ ?>
<tr>
<td><?php echo $row['fname'];?></td>
<td><?php echo $row['lname'];?></td>
</tr><?php
}
}?>
</table>
</form>

Answer 1

Your sample code is incomplete. The way it is written, many of your search options won't work. I would try selecting select2 and P1. That should work.
But there is potentially a bug in all of your IF statements. You shouldn't just test if a $_POST variable is set, you should make sure it's not NULL or zero length (strlen($var) > 0). Post variables can be "set" but still not have been submitted with actual data.
I would removed everything in your example that isn't related to select2 and see if you can get it to work in a much simpler format.
And of course smashing all of your SQL and PHP code in with a bunch of HTML is a bad idea, but that's not part of the question.