PHP nested MYSQL queries

Question

I use php and Mysql to query the database. I am trying to do the following:

Project Name 1
List todo
List todo
List todo 

Project Name 2
List todo
List todo
List todo 

I have the following mysql tables:

Project
project.projectId
project.projectName

Todo
todo.todoId
todo.todoEntry
todo.todoProjectid

I can query the table and pull out the entire list of projects, and then join todo. BUT, I want to create a title (project name), and then a loop under it.

I could execute a nested sql query for each parent-based todo, but for me it is not very efficient. Anyone suggest an improvement?

Answer 1

I made Gordon's request a little easier. Now it exactly fits your requirements.

SELECT
    `name`
FROM 
    (
        (SELECT 'project' as `type`, `name`, `id` as `projectid` FROM `Project`)
        UNION ALL
        (SELECT 'todo' as `type`, `name`, `projectid` FROM `Todo`)
    ) as `combined`
ORDER BY
    `project_id`, `type`

Result:

Result http://cl.ly/QXaG/Schermafbeelding%202013-07-30%20om%2014.58.46.png

---

PHP to get only a list of all lines:

$q = $db->query("SELECT `name` FROM ((SELECT 'project' as `type`, `name`, `id` as `project_id` FROM `projects`) union all (SELECT 'todo' as `type`, `name`, `project_id` FROM `todos`)) as `combined` ORDER BY `project_id`, `type`");

while($row = $q->fetch_object()) {
    echo $row->name . '<br />';
}

---

PHP "" :

$q = $db->query("SELECT `name`, `type` FROM ((SELECT 'project' as `type`, `name`, `id` as `project_id` FROM `projects`) union all (SELECT 'todo' as `type`, `name`, `project_id` FROM `todos`)) as `combined` ORDER BY `project_id`, `type`");

echo '<ul>';

$needToBeClosed = false;

while($row = $q->fetch_object()) {
    if($row->type == 'project' AND $needToBeClosed) {
        echo '</ul></li>';
        $needToBeClosed = false;
    }

    echo '<li>' . $row->name;

    if($row->type == 'project') {
        echo '<ul>';
        $needToBeClosed = true;
    } else {
        echo '</li>';
    }
}

if($needToBeClosed) {
    echo '</ul></li>';
}

echo '</ul>';

---

, . PHP . SQL PHP, . , , :

PHP "" :

$projects = $db->query('SELECT * FROM `projects`');

echo '<ul>';

while($project = $projects->fetch_object()) {
    echo '<li>' . $project->name . '<ul>';
    $todos = $db->query('SELECT * FROM `todos` WHERE `project_id` = ' . $project->id);

    while($todo = $todos->fetch_object()) {
        echo '<li>' . $todo->name . '</li>';
    }

    echo '</ul></li>';
}

echo '</ul>';

---

( ..).

Answer 2

, . Project, - Todo. , :

select which, name
from ((select 'Project' as which, name, 1 as ordering, projectid, NULL as id
       from  Project p
      ) union all
      (select 'List' as which, entry, 2 as ordering, projectid, id
       from Todo t
      )
     ) t
order by projectid,
         ordering,
         id;