MariaDB: Multiple joins and where clause searching for 1 in TINYINT Column not working

Question

I have tables called person and book and image and bookhit.

Person has id, name and Book has id, owner_id, info and Image has a column for id, owner_id, url and thumbnail which is a TINYINT (In the database half the rows are 0s and 1s.) By the way, the image column stores images of the cover of the book in two version: big-one and thumbnail. The table bookhit stores the times the book has been retrieved from the database and has a column hits.

So I tried multiple INNER JOIN to retrieve all the thumbnails for the most popular books. The SQL Query is the following:

SELECT `imagehit`.`hits`, `person`.`name`, `book`.`info`, `image`.`url`, `image`.`thumbnail` FROM `imagehit`
INNER JOIN `person` ON `person`.`id`=`book`.`owner_id`
INNER JOIN `image` ON `image`.`owner_id`=`book`.`id`
ORDER BY `imagehit`.`hits` DESC
WHERE `image`.`thumbnail`=1
LIMIT 10;

And that doesn't work, even though half rows has 1s in image.thumbnail . If I change the following line:

WHERE `image`.`thumbnail`=1

To

WHERE `image`.`thumbnail`=0

It does work. Well, I went to the image table and did a simple query like the following:

SELECT * FROM `image` WHERE `image`.`thumbnail`=0;

And gave me total rows stored in the table. But when I browse image table in phpMyAdmin I see there are 1s stored in the table. :(

Any ideas why this happens? thank you in advance.

Table definitions:

CREATE TABLE `image` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `owner_id` int(11) NOT NULL,
 `thumbnail` tinyint(1) NOT NULL,
 `url` varchar(255) NOT NULL,
 PRIMARY KEY (`id`),
 UNIQUE KEY `image_url` (`url`),
 KEY `image_owner_id` (`owner_id`),
 CONSTRAINT `image_ibfk_1` FOREIGN KEY (`owner_id`) REFERENCES `book` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1450 DEFAULT CHARSET=utf8

CREATE TABLE `person` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(255) NOT NULL,
 `url` varchar(60) NOT NULL,
 PRIMARY KEY (`id`),
 UNIQUE KEY `person_url` (`url`),
) ENGINE=InnoDB AUTO_INCREMENT=6287 DEFAULT CHARSET=utf8

CREATE TABLE `book` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `owner_id` int(11) NOT NULL,
 `book` varchar(3000) NOT NULL,
 `info` varchar(3000) NOT NULL,
 `url` varchar(60) NOT NULL,
 PRIMARY KEY (`id`),
 UNIQUE KEY `book_url` (`url`),
 KEY `book_owner_id` (`owner_id`),
 CONSTRAINT `book_ibfk_1` FOREIGN KEY (`owner_id`) REFERENCES `person` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=725 DEFAULT CHARSET=utf8

CREATE TABLE `imagehit` (
 `id` int(11) NOT NULL AUTO_INCREMENT,
 `owner_id` int(11) NOT NULL,
 `person_id` int(11) NOT NULL,
 `hits` int(11) NOT NULL,
 PRIMARY KEY (`id`),
 KEY `imagehit_person_id` (`person_id`),
 KEY `imagehit_owner_id` (`owner_id`),
 KEY `hits` (`hits`),
 CONSTRAINT `imagehit_ibfk_1` FOREIGN KEY (`owner_id`) REFERENCES `image` (`id`),
 CONSTRAINT `imagehit_ibfk_2` FOREIGN KEY (`person_id`) REFERENCES `person` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=725 DEFAULT CHARSET=utf8

Proof I'm not crazy:

I inserted the data using Peewee, when I created the row I set thumbnail=True if the image was a thumbnail and as thumbnail=False if it wasn't. The column thumbnail is the field BooleanField in Peewee.