For years, SQLite has been my go-to solution for storing any kind of structured local data for apps. The ability to update multiple pieces of data in a transaction has been extremely useful.

Naturally, when building my app in Tauri, I wanted to use SQLite from my Rust backend code.

A bit of poking around led toRusqlite for an ergonomic SQLite wrapper.

But there's a couple other questions to answer in order to tie it in with Tauri.

Where do you store the SQLite file?

Insidesetup() we can create an app handle and callapp_handle.path_resolver().app_data_dir(). That's the designated place to store our app data. From there we can initialize our DB file.

How do we access theConnection from a Tauri command?

Tauri has a built-in ability to store app state. We'll set up struct to hold it:

pubstructAppState{pubdb:std::sync::Mutex<Option<Connection>>,}

The Mutex protects access to the connection object. The idea is that you get theConnection, run a query on it, then release the Mutex.

Insetup() we can populate this app state with the DB connection.

letapp_state:State<AppState>=handle.state();*app_state.db.lock().unwrap()=Some(db);

We can also add a convenience trait to easily access theConnection object without jumping through theState fetch andMutex lock.

pubtraitServiceAccess{fndb<F,TResult>(&self,operation:F)->TResultwhereF:FnOnce(&Connection)->TResult;}implServiceAccessforAppHandle{fndb<F,TResult>(&self,operation:F)->TResultwhereF:FnOnce(&Connection)->TResult{letapp_state:State<AppState>=self.state();letdb_connection_guard=app_state.db.lock().unwrap();letdb=db_connection_guard.as_ref().unwrap();operation(db)}}

Inside Tauri commands we can supply aapp_handle: AppHandle argument, which will be automatically populated by the Tauri framework. From there we can call ourdb() trait method onapp_handle to do database operations. Anything returned from the closure will be passed through.

letmy_result=app_handle.db(|db:&Connection|{/* Do something with the DB connection and return a value */});

I pass theAppHandle through to any other modules that need it, so they also have access to theConnection. You can also callapp_handle.clone() in case you run into ownership issues.

Full example code

https://github.com/RandomEngy/tauri-sqlite