I have a table, `myTable`, with a single column, `myColumn`, with a single row.

I want to change the value of `myColumn` in that first (and only) row.

I tried this, but nothing happens:

```php
$myNewValue = 'foo';
$this->db->update('myColumn', $myNewValue);

```

What am I doing wrong?

Obviously it must have something to do with not specifying which table, but I don't know how to do that.