Chapter 20. Objects and SQL

20.1 The object-relational impedance mismatch 452
20.2 Encapsulating and hiding SQL 453
20.3 Generalizing SQL 459
20.4 Summary 469

I’ve never designed physical products, only software. But I’ve noticed that physical objects, no matter what their shapes, tend to be packaged in rectangular boxes and crates. An example would be the broadband router I received in the mail a while ago. There was the router itself, neatly box-shaped, an AC adapter, which is much more irregular, a cable folded and packaged with a clip, and an installation guide. All of this was safely ensconced in an unsurprisingly rectangular cardboard box with the aid of some extra packaging materials.

Although I’m anything but an expert on this kind ...

Get PHP in Action now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.