I have this weird problem. For some reason only certain row is selected. I have this `user_data` table: 
![enter image description here](https://i.stack.imgur.com/GYSa1.png)

and `website_name` table
![enter image description here](https://i.stack.imgur.com/1mTK5.png)

For some reason with this command using user id `13` it works:

![enter image description here](https://i.stack.imgur.com/havU0.png)

but using user id `27` it didn't but you can see I add #27 in `email_id` row gumblar.cn.

![enter image description here](https://i.stack.imgur.com/bOxxO.png)

Why it won't work with id 27? I'm using this command:

```
SELECT `email_address`, `handset` FROM `website_name` JOIN `user_data` USING ( id ) WHERE `email_id` ='27'

```

Any help and explanation is appreciated. Thanks in advance.