Summary

This chapter began with an overview of how local databases are deployed to Windows Phone.

The chapter explored the code-first approach to data model creation and walked through a sample Twitter timeline viewer that caches data in a local database, during which you explored several facets of LINQ to SQL including entity creation, change tracking, and entity multiplicity.

The chapter then looked at the database-first approach to data model creation. You saw how to retrieve a local database file from isolated storage and how to use the SqlMetal tool to generate a data model from a database.

The chapter then examined a custom navigation service that allows navigation from a viewmodel without reliance on the built-in navigation of the phone, which can increase the testability of viewmodel classes.

A technique for observing LINQ to SQL queries using a custom log was discussed. You saw how to upgrade a schema without losing data, and how to use version numbering to provide incremental updates to your database schema.

Finally, the chapter looked at mapping inheritance hierarchies using LINQ to SQL, and at concurrency and conflict detection.