Filter by category (for Jason)

select_category.php

<?php
	require_once  '_includes/connect.php';
	//added error reporting for debugging
	error_reporting(E_ALL);
	ini_set('display_errors', 'On');

	//define table
		$tbl = "items";//change to your table i.e. John_app
		$tbl2 = "photos";
		$tblCategories = "categories";
		if (empty($_REQUEST["category"])) {
    	$category = '%';   
		}else{  
		   $category = $_REQUEST["category"]; //tech, personal in my case
		}
		
	//write query
		//$query = "SELECT $tbl.itemID, $tbl.title, $tbl.description, $tbl.price, $tbl2.src FROM $tbl INNER JOIN $tbl2 ON $tbl.itemID = $tbl2.itemID";
		$query = "SELECT $tbl.itemID, $tbl.title, $tbl.description, $tbl.price, $tbl2.src, $tblCategories.category 
							FROM $tbl
							INNER JOIN $tblCategories ON $tbl.itemID = $tblCategories.itemID 
							INNER JOIN $tbl2 ON $tbl.itemID = $tbl2.itemID
							AND $tblCategories.category LIKE ?
							GROUP BY $tbl.itemID";
	//prepare statement, execute, store_result
		if($displayStmt = $mysqli->prepare($query)){
			$displayStmt->bind_param('s', $category);//added this!
			$displayStmt->execute();
			$displayStmt->store_result();
			$numrows = $displayStmt-> num_rows;
			//echo("<br>results: $numrows");
		}
	//bind results
		$displayStmt->bind_result($IDResult, $titleResult, $descriptionResult, $priceResult, $srcResult, $categoryResult);
	
    $itemsArray = [];
    //fetch results
		while($displayStmt->fetch()){

      $itemsArray[] = [$IDResult, $titleResult, $descriptionResult, $priceResult, $srcResult, $categoryResult];

		}
    echo(json_encode($itemsArray));
	?>

See the demo online
http://www.micromediaweb.com/home/nortonb/hypertext/store/select_category.php?category=personal
http://www.micromediaweb.com/home/nortonb/hypertext/store/select_category.php?category=tech
http://www.micromediaweb.com/home/nortonb/hypertext/store/select_category.php
(blank category selects all)