i faced a unique problem by accident

But before that i want to show you a table structure

td\_category

```
|---------------------------------------------------------------------|
|  category_id |  category_title  |  category_slug  |  p_cid          |
|---------------------------------------------------------------------|
|      1       |   Shirts         |   1-Shirts      |     0           |
|---------------------------------------------------------------------|
|      2       |   Jeans          |   2-Jeans       |     0           |
|---------------------------------------------------------------------|

```

Now, 

```
category_id is INT and auto-increment value
category_title is VARCHAR
category_slug is VARCHAR

```

Now what i amdoing is that, by mistake i wrote a query

```
SELECT * FROM td_category WHERE category_id = '2-Jeans'

```

and instead of giving me any error it displayed the 2nd tuple

Isn't it supposed to throw an error??

please can anybody clarify?