Add example to use rustqlite to persist the example into a local file

This includes very simple error logging, prompting the user to replace
the DB file if it exists on concecutive runs.

.gitignore

@@ -1,2 +1,3 @@
 /target
 /Cargo.lock
+/examples/hello-toasty-rustqlite/*.sql

Cargo.toml

@@ -16,6 +16,7 @@ members = [
     # Examples
     "examples/composite-key",
     "examples/hello-toasty",
+    "examples/hello-toasty-rustqlite",
     "examples/cratehub",
     "examples/user-has-one-profile",
 

examples/hello-toasty-rustqlite/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "example-hello-toasty-rustqlite"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+toasty = { path = "../../src/toasty" }
+toasty-sqlite = { path = "../../src/db/sqlite" }
+
+tokio = { version = "1.18", features = ["full"] }

examples/hello-toasty-rustqlite/schema.toasty

@@ -0,0 +1,28 @@
+model User {
+    #[key]
+    #[auto]
+    id: Id,
+
+    name: String,
+
+    #[unique]
+    email: String,
+
+    todos: [Todo],
+
+    moto: Option<String>,
+}
+
+model Todo {
+    #[key]
+    #[auto]
+    id: Id,
+
+    #[index]
+    user_id: Id<User>,
+
+    #[relation(key = user_id, references = id)]
+    user: User,
+
+    title: String,
+}

examples/hello-toasty-rustqlite/src/db/mod.rs

@@ -0,0 +1,7 @@
+#![allow(non_upper_case_globals, dead_code, warnings)]
+
+mod user;
+pub use user::User;
+
+mod todo;
+pub use todo::Todo;