I have a PHP loop that's auto-generating an array to INSERT into a table. But I get this error:

```
Database query failed: Incorrect integer value: '' for column 'id' at row 1
Last SQL query: INSERT INTO users(id, email, password, first_name, last_name) VALUES ('', 'test@user.com', 'fljhdsfsd', 'John', 'Doe')

```

I've tried setting the id field as No Null and Null, but that didn't help.

Any ideas? Thanks in advance for your help.