How to write a SQL query with a sub-select?

Question

MySQL

Hello,
There is a table tasks
id | task_name | task_created
------------------------------------------------
1 | Bring water | 15-09-2017
2 | Feed the cats | 14-09-2017
3 | Scratch dogs| 12-09-2017
4 | Borrow money | 15-09-2017
(two tasks created on the 15th)
And table uploads
id | image_path | timestamp
-----------------------------------------------------
1 | cat.jpg | 05-09-2017
2 | dogs.jpg | 15-09-2017
3 | birds.jpg | 12-09-2017
4 | star.jpg | 15-09-2017
(two uploads created on the 15th)
What I want: I want to get all the records from the tasks table, as well as the image_path from the uploads table, which has the same uploads.timestamp as task.task_created. If the task was created on 09/10/2017, and there are no records with this date in uploads, I want to get null in the column on the right table (uploads.timestamp field).
Important: for one task, you need to get one path to the picture with a condition like LIMIT 1 ORDER BY id ASC
I wrote something similar:

SELECT task_name, image_path FROM tasks left join uploads on (uploads.timestamp = tasks.task_created)

, but the results are duplicated in the selection, and I think that this should be written not through join, but with a nested select.
I would be very grateful for your help!
UPDATE: Thank you all so much. You are certainly right about foreign keys and the wrong selection logic, but the subtlety is that several pictures can be "attached" to one task, and tasks created throughout the day can have the same picture.
Right now I need to get a list of all tasks, and one picture for the task of a certain day, and with another request, for another page, I will get the paths to all the pictures of the current day, and twist them in the slider.
The logic is zero, but whoever pays orders the music.

Answer 1

SELECT task_name, 
  (SELECT image_path FROM uploads 
       WHERE uploads.timestamp = tasks.task_created 
        LIMIT 1) as im_path
FROM uploads

It's just a bad idea to implement a relationship by adding time, it's better to still refer to the primary key.

Answer 2

Your desire is due to an incorrectly designed base.
Read about the 3rd normal form of tables.
In this case, you need to:
a) task has strictly 1 or 0 pictures, pictures are only in tasks:
add the task_id field to uploads
b) otherwise:
create a new table xref_task_upload of the form (task_id, upload_id)

Answer 3

Your mistake is binding to timestamp which is not unique. You need to bind to a unique task id, that is, the uploads table should look like (id, image_path, task_id).
On existing data, you will either get a Cartesian product of tables, or one picture, for example dogs.jpg, will be attached to two different tasks.