如何遍历并一次显示1个DB记录？

Question

I'm making a simple item picking system in which the user will use a button that will display an item and then once picked will be pressed and display the next item in the next row.

Currently, when the button is pressed it will show the first item, then once pressed again will show the first item along with the second item, then third and so on.

An example would be:

first press: item1

second press: item1, item2

I need to figure out how to display just one item at a time while it's going through the table. Any help would be appreciated, thank you. Here's my button:

<script>
var offset = 0;

 $(document).ready(function () {
$('#button1').click(function (e) {
    $("#div1").empty();
          // pass offset value with GET request
    $.getJSON("getItem.php?offset=" + offset,     function(result){

      offset++; // increment the value after sucessful AJAX call
      $.each(result, function(i, field){
        $("#div1").empty();

    $("#div1").append(JSON.stringify(result));     
      });
    });
  });
});
</script>

Here's my getitem.php

mysqli_select_db($con,"items");
$rows = null;
// Get the offset value
$offset = empty($_GET['offset']) ? 0 : $_GET['offset'];

$sql="SELECT * FROM items Limit 1, $offset "; // pass the offset value to LIMIT query

$result = mysqli_query($con,$sql);
while($row = mysqli_fetch_assoc($result))
$rows[] = array_map('utf8_encode', $row);

echo json_encode($rows);

Answer 1

The problem is the LIMIT section of your query. The first part where you put "1" is actually the offset and the second one where you got $offset is the count value.

It probably should be something like that:

$sql="SELECT * FROM items LIMIT $offset, 1";

Answer 2

You can select all your items from DB the first time and store them into an array. Every time the user click the button, you can use the offset to select the item from that array.

In this way you avoid to make a new http request for every object/click. Unless you have an infinite number of objects and/or the object size is very large.