Answer 1

Vepa Orazov Hey, you don't need where clause at all.

INSERT INTO items
VALUES ('The' , 'Thing', 1, 2, 'img.png')

Answer 2

r8w9 is right. INSERT INTO does not come with WHERE field.

If you need to update existng record, you should use UPDATE.

UPDATE items SET `title`=?, `text`=?, `image`=? WHERE `user_id`=? AND `category_id`=?

If you use PDO, You need to use prepare and bindvalue to bing the user id and category id before execute it.

Answer 3

Really, why you need where clause there? As I know INSERT ... VALUES.. doesn't go with where, if you want to filter out some values you can do it differently for ie:
If (condition) INSERT... VALUES...