Is there a better way to list all database terms alphabetically?

Question

I have a wordpress site (still in development on my localhost, sorry I can't provide a link) that provides definitions and explanations for common 6th grade math concepts. The main part of the site is a concept map or web, but my boss also wants us to provide a functionality to browse the terms alphabetically, like a dictionary or index.

So what she wants is commonly available on the web: All the terms that start with A listed under 'A', all the terms that start with B listed under 'B', etc. I can retrieve all the terms from the database and sort them, but I am unsure of the best way to display them.

Example: The web page should look like this:

A
• apple
• artichoke
• avocado

B
• banana
• blueberry
etc.

I am thinking that I could build the HTML framework, and within each letter's div query the database for all the terms that start with that letter. Like this (in psuedocode):

<div id='a-section'>
<?php $terms=$wpdb->get_results("all terms that start with A");
      foreach( $terms as $term ) {  ?>
          <a link-to-definition><?php echo $term ?></a>
      <?php } ?>
</div>
<div id='b-section'>
  ....

For this, I would need 26 queries to the database, so I am thinking this method would be fairly inefficient. Can I do better? What if I retrieved all the terms in one query, sorted them alphabetically, and looked at the first letter of each term? Would that work? It seems a while( "a" == first-letter-of-$term ) may not work inside the foreach( $results as $term ), since the foreach loop will only execute once for each $term. But I don't really want to write 26 (27, actually, since some terms start with numerals) if( "a" == first-letter-of-$term ) statements inside the foreach loop.

I hope I've explained this dilemma clearly. Can anyone suggest how I should proceed? I would think someone has done something like this, but google didn't help me find any answers. Thanks in advance.

Answer 1

The comment from @czerspalace put me on the right track to doing what I needed. Since the first few terms start with numbers, this is how I implemented my solution:

// get results from $wpdb in object called $links
$glossary_ltr = "999";
foreach( $links as $link ) {
    $kw_ltr = substr( $link->keyword, 0, 1 ); // get first letter
    if( $glossary_ltr != $kw_ltr ) { 
        if( $kw_ltr > $glossary_ltr ) {
            // code to transition to new letter
            $glossary_ltr = $kw_ltr;
        }
    } // if letters are different
    // print out term
    echo "<a onclick='openTerm(/* term data */)'>". $link->keyword . "</a><br>";
} // foreach

Hope this helps someone else!