Rating: 

There is some useful information in this book, I started with chapter 7 and it explains how to model your data. From then on it gets into the detective agency example and quickly loses the reader.

I had to go and look for the downloaded examples to try and make sense of what was being written. I'm happy to follow a book building my own copy of the database that they describe and then use it for the next chapter. You can't do that with this book as the example files for the next chapter contain more work in them than is explained in the book. This slows you down as you have to try and work out what the changes are and what they are for.

I still haven't worked out how the detective agency databsae is supposed to work or what it is trying to achieve. Too many jumps without a suitable explanation make it very hard to understand.

What's a line item, how is that different to an expense and why does it have an invoice ID? I can see what you're trying to get at but not being an accountant doesn't make following the example easy at all.

The style of the book is a bit like being in a room with 5 different people talking at the same time, there are too many unrelated examples littering the page and because of that you find yourself having to refer to diagrams several pages forward or back from where you are in the book.

I have other Missing Manual books and I don't feel that this is up to the same standard.