tauri-impl-database
tauri-impl-database
Decision Tree: Which Storage Approach
Need persistent data in Tauri 2?
|
+-- Simple key-value pairs (settings, preferences, cache)?
| --> tauri-plugin-store (Section 1)
|
+-- Relational data with SQL queries?
| |
| +-- Frontend-driven queries (JS/TS calls SQL directly)?
| | --> tauri-plugin-sql (Section 2)
| |
| +-- Backend-driven queries (Rust owns the data layer)?
| --> Custom DB via Rust commands (Section 3)
|
+-- Encrypted storage for secrets?
--> tauri-plugin-stronghold (out of scope, see plugin docs)
Section 1: tauri-plugin-store (Key-Value Storage)
When to Use
Use tauri-plugin-store for user preferences, application settings, small cache data, and any scenario where you need persistent key-value pairs without relational queries.
Setup
Rust side (src-tauri/Cargo.toml):
[dependencies]
tauri-plugin-store = "2"
Register the plugin (src-tauri/src/lib.rs):
tauri::Builder::default()
.plugin(tauri_plugin_store::Builder::default().build())
.run(tauri::generate_context!())
.expect("error while running tauri application");
Frontend side (package.json):
{
"dependencies": {
"@tauri-apps/plugin-store": "^2"
}
}
Permissions (src-tauri/capabilities/default.json):
{
"permissions": ["store:default"]
}
Eager Loading Pattern
ALWAYS use eager loading when you need the store immediately at component mount or app startup.
import { load } from '@tauri-apps/plugin-store';
// Eager: loads from disk immediately, awaits until ready
const store = await load('settings.json', { autoSave: true });
// CRUD operations
await store.set('theme', 'dark');
await store.set('user', { name: 'Alice', prefs: { lang: 'en' } });
const theme = await store.get<string>('theme');
// Returns undefined if key does not exist -- ALWAYS handle this
const hasKey = await store.has('theme');
// Enumeration
const allKeys = await store.keys();
const allValues = await store.values();
const allEntries = await store.entries();
const count = await store.length();
// Deletion
await store.delete('theme');
await store.clear();
// Manual persistence (only needed when autoSave is false)
await store.save();
// Reload from disk (discard in-memory changes)
await store.reload();
// Reset to default values
await store.reset();
Lazy Loading Pattern
Use LazyStore when the store is referenced in multiple places but first access timing is uncertain. The store initializes on first operation.
import { LazyStore } from '@tauri-apps/plugin-store';
// Does NOT load from disk yet
const store = new LazyStore('cache.json');
// First operation triggers disk load automatically
await store.set('lastSync', Date.now());
const lastSync = await store.get<number>('lastSync');
Critical Rules
NEVER assume store.get() returns a value. It returns undefined for missing keys.
NEVER store large binary data in the store. It serializes to JSON on disk. Use the filesystem plugin for binary files.
ALWAYS call await store.save() if autoSave is false. Data loss occurs on app exit without save.
ALWAYS use await load(...) before calling store methods when using eager loading. Calling methods on an unloaded store causes runtime errors.
Section 2: tauri-plugin-sql (SQLite from Frontend)
When to Use
Use tauri-plugin-sql when the frontend needs direct SQL access for relational data, and you prefer writing queries in TypeScript rather than exposing individual Rust commands for each operation.
Setup
Rust side (src-tauri/Cargo.toml):
[dependencies]
tauri-plugin-sql = { version = "2", features = ["sqlite"] }
Register the plugin (src-tauri/src/lib.rs):
use tauri_plugin_sql::{Migration, MigrationKind};
let migrations = vec![
Migration {
version: 1,
description: "create_initial_tables",
sql: "CREATE TABLE IF NOT EXISTS users (
id INTEGER PRIMARY KEY AUTOINCREMENT,
name TEXT NOT NULL,
email TEXT UNIQUE NOT NULL,
created_at DATETIME DEFAULT CURRENT_TIMESTAMP
);",
kind: MigrationKind::Up,
},
Migration {
version: 2,
description: "add_settings_table",
sql: "CREATE TABLE IF NOT EXISTS settings (
key TEXT PRIMARY KEY,
value TEXT NOT NULL
);",
kind: MigrationKind::Up,
},
];
tauri::Builder::default()
.plugin(
tauri_plugin_sql::Builder::default()
.add_migrations("sqlite:app.db", migrations)
.build(),
)
.run(tauri::generate_context!())
.expect("error while running tauri application");
Frontend side (package.json):
{
"dependencies": {
"@tauri-apps/plugin-sql": "^2"
}
}
Permissions (src-tauri/capabilities/default.json):
{
"permissions": ["sql:default"]
}
Frontend CRUD Operations
import Database from '@tauri-apps/plugin-sql';
// Connect (creates file if it does not exist)
const db = await Database.load('sqlite:app.db');
// INSERT with parameters (ALWAYS use parameterized queries)
await db.execute(
'INSERT INTO users (name, email) VALUES ($1, $2)',
['Alice', 'alice@example.com']
);
// SELECT
const users = await db.select<Array<{
id: number;
name: string;
email: string;
}>>('SELECT * FROM users WHERE name = $1', ['Alice']);
// UPDATE
const result = await db.execute(
'UPDATE users SET name = $1 WHERE id = $2',
['Bob', 1]
);
console.log(`Rows affected: ${result.rowsAffected}`);
// DELETE
await db.execute('DELETE FROM users WHERE id = $1', [1]);
// Close connection when done
await db.close();
Critical Rules
ALWAYS use parameterized queries ($1, $2, ...). NEVER concatenate user input into SQL strings.
ALWAYS define migrations in Rust before the app starts. The plugin runs migrations on first connection.
NEVER use Database.load() with an absolute file path. Use the sqlite: prefix with a relative name. The plugin resolves the path to the app data directory.
ALWAYS close the database connection when the component or page unmounts to prevent connection leaks.
Section 3: Custom Database via Rust Commands
When to Use
Use custom Rust commands when you need full control over the database layer: connection pooling, complex transactions, custom ORM (diesel), type-safe queries (sqlx), or when the database logic belongs in the backend.
Pattern: sqlx with SQLite
Rust side (src-tauri/Cargo.toml):
[dependencies]
sqlx = { version = "0.8", features = ["runtime-tokio", "sqlite"] }
tokio = { version = "1", features = ["full"] }
serde = { version = "1", features = ["derive"] }
serde_json = "1"
thiserror = "2"
Database state and connection (src-tauri/src/db.rs):
use sqlx::sqlite::{SqlitePool, SqlitePoolOptions};
use std::path::PathBuf;
pub struct DbState {
pub pool: SqlitePool,
}
pub async fn init_db(db_path: PathBuf) -> Result<SqlitePool, sqlx::Error> {
let db_url = format!("sqlite:{}?mode=rwc", db_path.display());
let pool = SqlitePoolOptions::new()
.max_connections(5)
.connect(&db_url)
.await?;
// Run migrations
sqlx::query(
"CREATE TABLE IF NOT EXISTS items (
id INTEGER PRIMARY KEY AUTOINCREMENT,
title TEXT NOT NULL,
done BOOLEAN NOT NULL DEFAULT 0
)"
)
.execute(&pool)
.await?;
Ok(pool)
}
Commands (src-tauri/src/commands.rs):
use crate::db::DbState;
use serde::Serialize;
#[derive(Debug, thiserror::Error)]
pub enum Error {
#[error(transparent)]
Sqlx(#[from] sqlx::Error),
#[error("item not found: {0}")]
NotFound(i64),
}
impl serde::Serialize for Error {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where S: serde::ser::Serializer {
serializer.serialize_str(self.to_string().as_ref())
}
}
#[derive(Serialize, sqlx::FromRow)]
pub struct Item {
id: i64,
title: String,
done: bool,
}
#[tauri::command]
pub async fn create_item(
state: tauri::State<'_, DbState>,
title: String,
) -> Result<i64, Error> {
let result = sqlx::query("INSERT INTO items (title) VALUES (?)")
.bind(&title)
.execute(&state.pool)
.await?;
Ok(result.last_insert_rowid())
}
#[tauri::command]
pub async fn get_items(
state: tauri::State<'_, DbState>,
) -> Result<Vec<Item>, Error> {
let items = sqlx::query_as::<_, Item>("SELECT * FROM items")
.fetch_all(&state.pool)
.await?;
Ok(items)
}
#[tauri::command]
pub async fn toggle_item(
state: tauri::State<'_, DbState>,
id: i64,
) -> Result<(), Error> {
let rows = sqlx::query("UPDATE items SET done = NOT done WHERE id = ?")
.bind(id)
.execute(&state.pool)
.await?
.rows_affected();
if rows == 0 {
return Err(Error::NotFound(id));
}
Ok(())
}
App setup (src-tauri/src/lib.rs):
mod commands;
mod db;
#[cfg_attr(mobile, tauri::mobile_entry_point)]
pub fn run() {
tauri::Builder::default()
.setup(|app| {
let db_path = app.path().app_data_dir()?.join("data.db");
// Ensure parent directory exists
if let Some(parent) = db_path.parent() {
std::fs::create_dir_all(parent)?;
}
let pool = tauri::async_runtime::block_on(async {
db::init_db(db_path).await
})?;
app.manage(db::DbState { pool });
Ok(())
})
.invoke_handler(tauri::generate_handler![
commands::create_item,
commands::get_items,
commands::toggle_item,
])
.run(tauri::generate_context!())
.expect("error while running tauri application");
}
Frontend call:
import { invoke } from '@tauri-apps/api/core';
const id = await invoke<number>('create_item', { title: 'Buy groceries' });
const items = await invoke<Array<{ id: number; title: string; done: boolean }>>('get_items');
await invoke('toggle_item', { id: 1 });
Critical Rules
ALWAYS initialize the database in the setup() hook and manage the pool as state. NEVER create connections inside individual commands.
ALWAYS ensure the database directory exists before connecting. Use app.path().app_data_dir() for the correct platform-specific path.
ALWAYS use async commands for all database operations. Sync database calls block the main thread and freeze the UI.
NEVER wrap the pool in Arc. Tauri already wraps managed state in Arc internally. SqlitePool is also internally Arc-wrapped.
ALWAYS use the thiserror + manual Serialize impl pattern for error types. See references/methods.md for the full pattern.
ALWAYS define custom command permissions when using this approach. See tauri-errors-permissions skill for the permission setup flow.
Reference Links
- references/methods.md -- API signatures for store, sql plugin, and sqlx patterns
- references/examples.md -- Complete working examples for each approach
- references/anti-patterns.md -- Common database integration mistakes