What book should I get to learn database design for Core Data?

>how do desing a complex database using Core Data.

Not sure it works like that.

From the docs:

https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/CoreData/index.html

"What Is Core Data?

Core Data is a framework that you use to manage the model layer objects in your application. It provides generalized and automated solutions to common tasks associated with object life cycle and object graph management, including persistence."

First determine your DB type, then identify the best management tools, then design and create it thru them, then hook into it via CD in your apps. Keep in mind that success implementing CD requires a non-trivial skill set, with and beyond, CD itself.

And while there are many good database books, I'd stick with Apple's docs for CD...books that attempt to support Apple's SDKs are typically out of date before they hit the shelves, leaving you without support, etc.