If what you are after is creating an application with an embedded database [
^] that does not use SQL: try SQLLite: [
^].
"SQLite is a software library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. SQLite is the most widely deployed SQL database engine in the world. The source code for SQLite is in the public domain."
There is one .NET implementation of SQLLite here: [
^]; another one (ADO.NET provider) here [
^]; another one here [
^].
Search CodeProject for "SQLLite" articles, and you'll find tutorials for using these.