Using a PHP variable as a MySQL query table name - php

Question

self taught at PHP so please spare me if i made any obvious errors,
im trying to dynamically create an accordion and have the corresponding content beneath each accordion header be created from its corresponding table,(if the header is tacos, the information below would come from the tacos_info table) some of the solutions i came up with im not sure about, cheifly passing a variable value as the table name in the mysqli query.
<?php
//initialize list
$res = mysqli_query("SELECT * FROM tables ORDER BY votes DESC");
//build the accordion header and div content in descending order
while($row= mysqli_fetch_assoc($res)){
//create value for SQL table name to build content
$dbname='$row['name']';
//create the accordion headers
$accordioncontent= '<h3>'.$row['name'].'</h3>';
//build the query that will be used to create the accordion content dynamically
$res2 = mysql_query("SELECT * FROM '$dbname' ORDER BY votes DESC");
//while loop to build the div content dynamically
while($row2= mysqli_fetch_assoc($res2)){
//dynamically create the list items i.e the accordion content
$ranks= '<li id="li $row2['id']">
<div class="tut-img">
<img src="<?php echo $row2['img']?>" width="50" height="70" alt="<?php $row['title']?>" />
</div>
<div class="title"><?php $row2['title']?>
</div>
</li>';
}//close content while loop
//create the submit button that submits according to each accordion divs content
$submitbutton='';
//limit submissions to once per IP, per table
$voted=false;
$vcheck= mysqli_query("SELECT 1 FROM sort_votes
WHERE ip='".$_SERVER['REMOTE_ADDR']."'
AND date_submit=CURDATE()
AND Tablename='$dbname' "
);
if(mysqli_num_rows($vcheck)==1)
$voted=true;
//conditional to assign either a submit or edit
if(!$votedIFC){$submitbutton='Enter opinion<span></span>'}
else{$submitbutton='Enter opinion<span></span>'}
//concatonate the div header with the div content
$accordioncontent .= '<div><ul class="sort" id="rank_ul">'$ranks'</ul><div class="button-holder">'$submitbutton'</div></div>';
}//close accordion while loop
//send all this data to the AJAX GET request
echo $accordioncontent;
?>
am i passing these values to the query correctly? is this allowed? if not what are better alternatives? any and all tips, input and knowledge is much appreciated.

Answer 1

First of all, I can see that you are using simple and double quotes sometimes in a strange way. Which IDE are you using for your development? My first recommendation, would be for you to use a proper editor that will automatically check your code syntax.
For example this seems strange (difficult to ready and will surely at one point generate an error):
'<li id="li $row2['id']"> ..... ';
In my opinion, a correct syntax here would be:
"<li id='li ".$row2['id']."'> .... ";
More details here: http://www.trans4mind.com/personal_development/phpTutorial/quotes.htm
Now to answers to your question, you seems to be more focused on the way you are passing the values to the SQL query. If you are looking for best practices, then I'd recommend you to use php PDO. It's a layer between PHP and your database that will among other things, make sure that the you correctly passed values to SQL (reduce risk of SQL injection, problem of quotes, etc ...).
More details about PDO here: http://code.tutsplus.com/tutorials/why-you-should-be-using-phps-pdo-for-database-access--net-12059
My last advises:
Please make efforts in the indentation of your code, it will be easier to read and understand for you and others and it will then avoid obvious errors.
Use correct variable name. For example you are here using $dbname to speak about database tables ...
Good luck.