How to display wordpress database values in table the right way? - php

Question

I am using wordpress to let people sign up for a task.
A normal post (i.e. project) has multiple tasks.
When a user wants to sign up for task1 his/hers usersname goes into the meta table in my database in a meta key field called task1. Multiple users can sign up for the same task.
I managed to display a table with the task titles and all the people who signed up for it. But I don't want to display the same title and the same tasknames multiple times. Can anybody help me out?
The current output is like this
Title Tasks Volunteers
Project 1 Task 1 user3
Project 1 Task 1 user6
Project 1 Task 1 user5
Project 1 Task 2 user2
Project 1 Task 2 user9
Project 2 Task 1 user1
Project 2 Task 2 user8
Project 2 Task 2 user4
And I want it to look like this
Title Tasks Volunteers
Project 1 Task 1 user3
user6
user5
Task 2 user2
user9
Project 2 Task 1 user1
Task 2 user8
user4
Here is my code.
I thought I use an INNER JOIN in my sql query because I need to get values from 2 tables (wp_1_posts and wp_1_postmeta).
<?php
$query = "SELECT *
FROM wp_1_posts
INNER JOIN wp_1_postmeta
ON wp_1_posts.id=wp_1_postmeta.post_id
WHERE wp_1_postmeta.meta_key='task1'
OR wp_1_postmeta.meta_key='task2'
ORDER BY post_title";
$result = mysql_query($query) or die(mysql_error());
?>
<table border='1'>
<tr>
<th>Title</th>
<th>Tasks</th>
<th>Volunteers</th>
</tr>
<?php
while($row = mysql_fetch_assoc($result))
{
$post_title = $row['post_title'];
$meta_key = $row['meta_key'];
$meta_value = $row['meta_value'];
if ($meta_key == 'task1'){
$task_name = "Task 1";
}
else if ($meta_key == 'task2'){
$task_name = "Task 2";
}
echo "<tr>";
echo "<td>". $post_title. "</td>";
echo "<td>". $task_name. "</td>";
echo "<td>". $meta_value. "</td>"; //names of volunteers
echo "</tr>";
}
?>
</table>

Answer 1

You can't get a result that looks like that with SQL. Those "holes" there aren't exactly something you'll have returned like that.
As commented, your INNER vs OUTER JOIN doesn't really make a difference in this case. I usually use LEFT JOIN (an outer join) for hooking up posts with post meta data.
However, I think you're ok. It's just in how you display the results. Remember that you need the title and task columns there in order to ascertain where each of the volunteers belong.
You're saying the same thing, but you're visualizing it differently. You're omitting some repetition for the end user that you are otherwise implying.
You could simply keep an array off to the side that keeps track of which tasks and titles you've already displayed, then on your loop if it it was already displayed, ensure it's set to an empty string.
For example:
$titles = array();
$tasks = array();
while($row = mysql_fetch_assoc($result)) {
// set the $post_title to the actual title or an empty string based on if it was already seen or not
$post_title = !in_array($row['post_title'], $titles) ? $row['post_title']:'';
// record that it has been seen
$titles[] = $row['post_title'];
// ...do the same for tasks and then the rest of your code as you had it
Keep in mind you will need to adjust that logic a little bit if your task names can appear multiple times under each title section. In that case you may want to keep a keyed array with title.task combinations.
Anyway, hopefully that gives you an idea on how to keep track of what you already displayed, in a relatively simple manner, so you can get the output you want.
SQL can't always return the perfect tabular result.
This is also a little problematic if you end up having many tasks:
if ($meta_key == 'task1'){
$task_name = "Task 1";
}
else if ($meta_key == 'task2'){
$task_name = "Task 2";
}
You could instead create a formatter helper function that would use PHP's ucwords() or ucfirst() functions and perhaps string replace or even a little more heavy regular expression to add spaces between numbers and such. I bet $10 you can find some snippet of code out there that can help you with making the titles pretty. The keyword here is "humanize" ... Many frameworks and snippets out there will have such helper utility classes and functions usually by that kinda phrasing.
You may also get lucky with a jQuery plugin of some sort (or some other JavaScript tool) that works with tabular data and can format it in the manner you're after. It might even provide some more advanced sorting options. Then you just might be able to JSON encode the table result and get exactly what you want in the format you need. That might be the closest you get to out of the box SQL result without any sort of formatting with PHP.