How to Use SQLite in Vue 3: Complete Guide to Offline-First Web Apps

Want to build web apps that work offline? While browsers have built-in storage options like IndexedDB, they’re not great for complex data operations. This guide shows you how to use SQLite with Vue 3 to build powerful offline-first apps.

📚 What We’ll Build

• A Vue 3 app with SQLite that works offline
• A simple query playground to test SQLite
• Everything runs in the browser - no server needed!

Try it out: Write and run SQL queries right in your browser

🚀 Want the code? Get the complete example at github.com/alexanderop/sqlite-vue-example

🗃️ Why SQLite?

Browser storage like IndexedDB is okay, but SQLite is better because:

• It’s a real SQL database in your browser
• Your data stays safe even when offline
• You can use normal SQL queries
• It handles complex data relationships well

🛠️ How It Works

We’ll use three main technologies:

1. SQLite Wasm: SQLite converted to run in browsers
2. Web Workers: Runs database code without freezing your app
3. Origin Private File System: A secure place to store your database

Here’s how they work together:

📝 Implementation Guide

Let’s build this step by step, starting with the core SQLite functionality and then creating a playground to test it.

Step 1: Install Dependencies

First, install the required SQLite WASM package:

npm install @sqlite.org/sqlite-wasm

Step 2: Configure Vite

Create or update your vite.config.ts file to support WebAssembly and cross-origin isolation:

import { function defineConfig(config: UserConfig): UserConfig (+3 overloads)
Type helper to make it easier to use vite.config.ts
accepts a direct 
{@link 
UserConfig
}
 object, or a function that returns it.
The function receives a 
{@link 
ConfigEnv
}
 object.defineConfig } from 'vite'

export default function defineConfig(config: UserConfigFnObject): UserConfigFnObject (+3 overloads)
Type helper to make it easier to use vite.config.ts
accepts a direct 
{@link 
UserConfig
}
 object, or a function that returns it.
The function receives a 
{@link 
ConfigEnv
}
 object.defineConfig(() => ({
  UserConfig.server?: ServerOptions | undefined
Server specific options, e.g. host, port, https...server: {
    CommonServerOptions.headers?: OutgoingHttpHeaders | undefined
Specify server response headers.headers: {
      'Cross-Origin-Opener-Policy': 'same-origin',
      'Cross-Origin-Embedder-Policy': 'require-corp',
    },
  },
  UserConfig.optimizeDeps?: DepOptimizationOptions | undefined
Dep optimization optionsoptimizeDeps: {
    DepOptimizationConfig.exclude?: string[] | undefined
Do not optimize these dependencies (must be resolvable import paths,
cannot be globs).exclude: ['@sqlite.org/sqlite-wasm'],
  },
}))

This configuration is crucial for SQLite WASM to work properly:

• Cross-Origin Headers:

  • Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers enable “cross-origin isolation”
  • This is required for using SharedArrayBuffer, which SQLite WASM needs for optimal performance
  • Without these headers, the WebAssembly implementation might fail or perform poorly

• Dependency Optimization:

  • optimizeDeps.exclude tells Vite not to pre-bundle the SQLite WASM package
  • This is necessary because the WASM files need to be loaded dynamically at runtime
  • Pre-bundling would break the WASM initialization process

Step 3: Add TypeScript Types

Since @sqlite.org/sqlite-wasm doesn’t include TypeScript types for Sqlite3Worker1PromiserConfig, we need to create our own. Create a new file types/sqlite-wasm.d.ts:

Define this as a d.ts file so that TypeScript knows about it.

import type { class Worker
The `Worker` class represents an independent JavaScript execution thread.
Most Node.js APIs are available inside of it.

Notable differences inside a Worker environment are:

* The `process.stdin`, `process.stdout`, and `process.stderr` streams may be redirected by the parent thread.
* The `require('node:worker_threads').isMainThread` property is set to `false`.
* The `require('node:worker_threads').parentPort` message port is available.
* `process.exit()` does not stop the whole program, just the single thread,
and `process.abort()` is not available.
* `process.chdir()` and `process` methods that set group or user ids
are not available.
* `process.env` is a copy of the parent thread's environment variables,
unless otherwise specified. Changes to one copy are not visible in other
threads, and are not visible to native add-ons (unless `worker.SHARE_ENV` is passed as the `env` option to the `Worker` constructor). On Windows, unlike the main thread, a copy of the
environment variables operates in a case-sensitive manner.
* `process.title` cannot be modified.
* Signals are not delivered through `process.on('...')`.
* Execution may stop at any point as a result of `worker.terminate()` being invoked.
* IPC channels from parent processes are not accessible.
* The `trace_events` module is not supported.
* Native add-ons can only be loaded from multiple threads if they fulfill `certain conditions`.

Creating `Worker` instances inside of other `Worker`s is possible.

Like [Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) and the `node:cluster module`, two-way communication
can be achieved through inter-thread message passing. Internally, a `Worker` has
a built-in pair of `MessagePort` s that are already associated with each
other when the `Worker` is created. While the `MessagePort` object on the parent
side is not directly exposed, its functionalities are exposed through `worker.postMessage()` and the `worker.on('message')` event
on the `Worker` object for the parent thread.

To create custom messaging channels (which is encouraged over using the default
global channel because it facilitates separation of concerns), users can create
a `MessageChannel` object on either thread and pass one of the`MessagePort`s on that `MessageChannel` to the other thread through a
pre-existing channel, such as the global one.

See `port.postMessage()` for more information on how messages are passed,
and what kind of JavaScript values can be successfully transported through
the thread barrier.

```js
const assert = require('node:assert');
const {
  Worker, MessageChannel, MessagePort, isMainThread, parentPort,
} = require('node:worker_threads');
if (isMainThread) {
  const worker = new Worker(__filename);
  const subChannel = new MessageChannel();
  worker.postMessage({ hereIsYourPort: subChannel.port1 }, [subChannel.port1]);
  subChannel.port2.on('message', (value) => {
    console.log('received:', value);
  });
} else {
  parentPort.once('message', (value) => {
    assert(value.hereIsYourPort instanceof MessagePort);
    value.hereIsYourPort.postMessage('the worker is sending this');
    value.hereIsYourPort.close();
  });
}
```
@sincev10.5.0Worker } from 'node:worker_threads'

declare module '@sqlite.org/sqlite-wasm' {
  type type OnreadyFunction = () => voidOnreadyFunction = () => void

  type 
type Sqlite3Worker1PromiserConfig = {
    onready?: OnreadyFunction;
    worker?: Worker | (() => Worker);
    generateMessageId?: (messageObject: unknown) => string;
    debug?: (...args: any[]) => void;
    onunhandled?: (event: MessageEvent) => void;
}Sqlite3Worker1PromiserConfig = {
    onready?: OnreadyFunction | undefinedonready?: type OnreadyFunction = () => voidOnreadyFunction
    worker?: Worker | (() => Worker) | undefinedworker?: class Worker
The `Worker` class represents an independent JavaScript execution thread.
Most Node.js APIs are available inside of it.

Notable differences inside a Worker environment are:

* The `process.stdin`, `process.stdout`, and `process.stderr` streams may be redirected by the parent thread.
* The `require('node:worker_threads').isMainThread` property is set to `false`.
* The `require('node:worker_threads').parentPort` message port is available.
* `process.exit()` does not stop the whole program, just the single thread,
and `process.abort()` is not available.
* `process.chdir()` and `process` methods that set group or user ids
are not available.
* `process.env` is a copy of the parent thread's environment variables,
unless otherwise specified. Changes to one copy are not visible in other
threads, and are not visible to native add-ons (unless `worker.SHARE_ENV` is passed as the `env` option to the `Worker` constructor). On Windows, unlike the main thread, a copy of the
environment variables operates in a case-sensitive manner.
* `process.title` cannot be modified.
* Signals are not delivered through `process.on('...')`.
* Execution may stop at any point as a result of `worker.terminate()` being invoked.
* IPC channels from parent processes are not accessible.
* The `trace_events` module is not supported.
* Native add-ons can only be loaded from multiple threads if they fulfill `certain conditions`.

Creating `Worker` instances inside of other `Worker`s is possible.

Like [Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) and the `node:cluster module`, two-way communication
can be achieved through inter-thread message passing. Internally, a `Worker` has
a built-in pair of `MessagePort` s that are already associated with each
other when the `Worker` is created. While the `MessagePort` object on the parent
side is not directly exposed, its functionalities are exposed through `worker.postMessage()` and the `worker.on('message')` event
on the `Worker` object for the parent thread.

To create custom messaging channels (which is encouraged over using the default
global channel because it facilitates separation of concerns), users can create
a `MessageChannel` object on either thread and pass one of the`MessagePort`s on that `MessageChannel` to the other thread through a
pre-existing channel, such as the global one.

See `port.postMessage()` for more information on how messages are passed,
and what kind of JavaScript values can be successfully transported through
the thread barrier.

```js
const assert = require('node:assert');
const {
  Worker, MessageChannel, MessagePort, isMainThread, parentPort,
} = require('node:worker_threads');
if (isMainThread) {
  const worker = new Worker(__filename);
  const subChannel = new MessageChannel();
  worker.postMessage({ hereIsYourPort: subChannel.port1 }, [subChannel.port1]);
  subChannel.port2.on('message', (value) => {
    console.log('received:', value);
  });
} else {
  parentPort.once('message', (value) => {
    assert(value.hereIsYourPort instanceof MessagePort);
    value.hereIsYourPort.postMessage('the worker is sending this');
    value.hereIsYourPort.close();
  });
}
```
@sincev10.5.0Worker | (() => class Worker
The `Worker` class represents an independent JavaScript execution thread.
Most Node.js APIs are available inside of it.

Notable differences inside a Worker environment are:

* The `process.stdin`, `process.stdout`, and `process.stderr` streams may be redirected by the parent thread.
* The `require('node:worker_threads').isMainThread` property is set to `false`.
* The `require('node:worker_threads').parentPort` message port is available.
* `process.exit()` does not stop the whole program, just the single thread,
and `process.abort()` is not available.
* `process.chdir()` and `process` methods that set group or user ids
are not available.
* `process.env` is a copy of the parent thread's environment variables,
unless otherwise specified. Changes to one copy are not visible in other
threads, and are not visible to native add-ons (unless `worker.SHARE_ENV` is passed as the `env` option to the `Worker` constructor). On Windows, unlike the main thread, a copy of the
environment variables operates in a case-sensitive manner.
* `process.title` cannot be modified.
* Signals are not delivered through `process.on('...')`.
* Execution may stop at any point as a result of `worker.terminate()` being invoked.
* IPC channels from parent processes are not accessible.
* The `trace_events` module is not supported.
* Native add-ons can only be loaded from multiple threads if they fulfill `certain conditions`.

Creating `Worker` instances inside of other `Worker`s is possible.

Like [Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) and the `node:cluster module`, two-way communication
can be achieved through inter-thread message passing. Internally, a `Worker` has
a built-in pair of `MessagePort` s that are already associated with each
other when the `Worker` is created. While the `MessagePort` object on the parent
side is not directly exposed, its functionalities are exposed through `worker.postMessage()` and the `worker.on('message')` event
on the `Worker` object for the parent thread.

To create custom messaging channels (which is encouraged over using the default
global channel because it facilitates separation of concerns), users can create
a `MessageChannel` object on either thread and pass one of the`MessagePort`s on that `MessageChannel` to the other thread through a
pre-existing channel, such as the global one.

See `port.postMessage()` for more information on how messages are passed,
and what kind of JavaScript values can be successfully transported through
the thread barrier.

```js
const assert = require('node:assert');
const {
  Worker, MessageChannel, MessagePort, isMainThread, parentPort,
} = require('node:worker_threads');
if (isMainThread) {
  const worker = new Worker(__filename);
  const subChannel = new MessageChannel();
  worker.postMessage({ hereIsYourPort: subChannel.port1 }, [subChannel.port1]);
  subChannel.port2.on('message', (value) => {
    console.log('received:', value);
  });
} else {
  parentPort.once('message', (value) => {
    assert(value.hereIsYourPort instanceof MessagePort);
    value.hereIsYourPort.postMessage('the worker is sending this');
    value.hereIsYourPort.close();
  });
}
```
@sincev10.5.0Worker)
    generateMessageId?: ((messageObject: unknown) => string) | undefinedgenerateMessageId?: (messageObject: unknownmessageObject: unknown) => string
    debug?: ((...args: any[]) => void) | undefineddebug?: (...args: any[]args: any[]) => void
    onunhandled?: ((event: MessageEvent) => void) | undefinedonunhandled?: (event: MessageEvent<any>event: interface MessageEvent<T = any>
A message received by a target object.

[MDN Reference](https://developer.mozilla.org/docs/Web/API/MessageEvent)
@sincev15.0.0MessageEvent) => void
  }

  type type DbId = string | undefinedDbId = string | undefined

  type 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods = {
    'config-get': {
      args: Record<string, never>args: type Record<K extends keyof any, T> = { [P in K]: T; }
Construct a type with a set of properties K of type TRecord<string, never>
      
result: {
    dbID: DbId;
    version: {
        libVersion: string;
        sourceId: string;
        libVersionNumber: number;
        downloadVersion: number;
    };
    bigIntEnabled: boolean;
    opfsEnabled: boolean;
    vfsList: string[];
}result: {
        dbID: DbIddbID: type DbId = string | undefinedDbId
        
version: {
    libVersion: string;
    sourceId: string;
    libVersionNumber: number;
    downloadVersion: number;
}version: {
          libVersion: stringlibVersion: string
          sourceId: stringsourceId: string
          libVersionNumber: numberlibVersionNumber: number
          downloadVersion: numberdownloadVersion: number
        }
        bigIntEnabled: booleanbigIntEnabled: boolean
        opfsEnabled: booleanopfsEnabled: boolean
        vfsList: string[]vfsList: string[]
      }
    }
    'open': {
      
args: Partial<{
    filename?: string;
    vfs?: string;
}>args: type Partial<T> = { [P in keyof T]?: T[P] | undefined; }
Make all properties in T optionalPartial<{
        filename?: string | undefinedfilename?: string
        vfs?: string | undefinedvfs?: string
      }>
      
result: {
    dbId: DbId;
    filename: string;
    persistent: boolean;
    vfs: string;
}result: {
        dbId: DbIddbId: type DbId = string | undefinedDbId
        filename: stringfilename: string
        persistent: booleanpersistent: boolean
        vfs: stringvfs: string
      }
    }
    'exec': {
      
args: {
    sql: string;
    dbId?: DbId;
    bind?: unknown[];
    returnValue?: string;
}args: {
        sql: stringsql: string
        dbId?: DbIddbId?: type DbId = string | undefinedDbId
        bind?: unknown[] | undefinedbind?: unknown[]
        returnValue?: string | undefinedreturnValue?: string
      }
      
result: {
    dbId: DbId;
    sql: string;
    bind: unknown[];
    returnValue: string;
    resultRows?: unknown[][];
}result: {
        dbId: DbIddbId: type DbId = string | undefinedDbId
        sql: stringsql: string
        bind: unknown[]bind: unknown[]
        returnValue: stringreturnValue: string
        resultRows?: unknown[][] | undefinedresultRows?: unknown[][]
      }
    }
  }

  type 
type PromiserResponseSuccess<T extends keyof PromiserMethods> = {
    type: T;
    result: PromiserMethods[T]["result"];
    messageId: string;
    dbId: DbId;
    workerReceivedTime: number;
    workerRespondTime: number;
    departureTime: number;
}PromiserResponseSuccess<function (type parameter) T in type PromiserResponseSuccess<T extends keyof PromiserMethods>T extends keyof 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods> = {
    type: T extends keyof PromiserMethodstype: function (type parameter) T in type PromiserResponseSuccess<T extends keyof PromiserMethods>T
    result: PromiserMethods[T]["result"]result: 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods[function (type parameter) T in type PromiserResponseSuccess<T extends keyof PromiserMethods>T]['result']
    messageId: stringmessageId: string
    dbId: DbIddbId: type DbId = string | undefinedDbId
    workerReceivedTime: numberworkerReceivedTime: number
    workerRespondTime: numberworkerRespondTime: number
    departureTime: numberdepartureTime: number
  }

  type 
type PromiserResponseError = {
    type: "error";
    result: {
        operation: string;
        message: string;
        errorClass: string;
        input: object;
        stack: unknown[];
    };
    messageId: string;
    dbId: DbId;
}PromiserResponseError = {
    type: "error"type: 'error'
    
result: {
    operation: string;
    message: string;
    errorClass: string;
    input: object;
    stack: unknown[];
}result: {
      operation: stringoperation: string
      message: stringmessage: string
      errorClass: stringerrorClass: string
      input: objectinput: object
      stack: unknown[]stack: unknown[]
    }
    messageId: stringmessageId: string
    dbId: DbIddbId: type DbId = string | undefinedDbId
  }

  type type PromiserResponse<T extends keyof PromiserMethods> = PromiserResponseError | PromiserResponseSuccess<T>PromiserResponse<function (type parameter) T in type PromiserResponse<T extends keyof PromiserMethods>T extends keyof 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods> =
    | 
type PromiserResponseSuccess<T extends keyof PromiserMethods> = {
    type: T;
    result: PromiserMethods[T]["result"];
    messageId: string;
    dbId: DbId;
    workerReceivedTime: number;
    workerRespondTime: number;
    departureTime: number;
}PromiserResponseSuccess<function (type parameter) T in type PromiserResponse<T extends keyof PromiserMethods>T>
    | 
type PromiserResponseError = {
    type: "error";
    result: {
        operation: string;
        message: string;
        errorClass: string;
        input: object;
        stack: unknown[];
    };
    messageId: string;
    dbId: DbId;
}PromiserResponseError

  type type Promiser = <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]) => Promise<PromiserResponse<T>>Promiser = <function (type parameter) T in <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]): Promise<PromiserResponse<T>>T extends keyof 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods>(
    messageType: T extends keyof PromiserMethodsmessageType: function (type parameter) T in <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]): Promise<PromiserResponse<T>>T,
    messageArguments: PromiserMethods[T]["args"]messageArguments: 
type PromiserMethods = {
    'config-get': {
        args: Record<string, never>;
        result: {
            dbID: DbId;
            version: {
                libVersion: string;
                sourceId: string;
                libVersionNumber: number;
                downloadVersion: number;
            };
            bigIntEnabled: boolean;
            opfsEnabled: boolean;
            vfsList: string[];
        };
    };
    open: {
        args: Partial<{
            filename?: string;
            vfs?: string;
        }>;
        result: {
            dbId: DbId;
            filename: string;
            persistent: boolean;
            vfs: string;
        };
    };
    exec: {
        args: {
            sql: string;
            dbId?: DbId;
            bind?: unknown[];
            returnValue?: string;
        };
        result: {
            dbId: DbId;
            sql: string;
            bind: unknown[];
            returnValue: string;
            resultRows?: unknown[][];
        };
    };
}PromiserMethods[function (type parameter) T in <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]): Promise<PromiserResponse<T>>T]['args'],
  ) => interface Promise<T>
Represents the completion of an asynchronous operationPromise<type PromiserResponse<T extends keyof PromiserMethods> = PromiserResponseError | PromiserResponseSuccess<T>PromiserResponse<function (type parameter) T in <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]): Promise<PromiserResponse<T>>T>>

  export function function sqlite3Worker1Promiser(config?: Sqlite3Worker1PromiserConfig | OnreadyFunction): Promisersqlite3Worker1Promiser(
    config: OnreadyFunction | Sqlite3Worker1PromiserConfig | undefinedconfig?: 
type Sqlite3Worker1PromiserConfig = {
    onready?: OnreadyFunction;
    worker?: Worker | (() => Worker);
    generateMessageId?: (messageObject: unknown) => string;
    debug?: (...args: any[]) => void;
    onunhandled?: (event: MessageEvent) => void;
}Sqlite3Worker1PromiserConfig | type OnreadyFunction = () => voidOnreadyFunction,
  ): type Promiser = <T extends keyof PromiserMethods>(messageType: T, messageArguments: PromiserMethods[T]["args"]) => Promise<PromiserResponse<T>>Promiser
}

Step 4: Create the SQLite Composable

The core of our implementation is the useSQLite composable. This will handle all database operations:

import type { import DbIdDbId } from '@sqlite.org/sqlite-wasm'
import { import sqlite3Worker1Promisersqlite3Worker1Promiser } from '@sqlite.org/sqlite-wasm'
import { function ref<T>(value: T): [T] extends [Ref] ? IfAny<T, Ref<T>, T> : Ref<UnwrapRef<T>, UnwrapRef<T> | T> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref } from 'vue'

const 
const databaseConfig: {
    readonly filename: "file:mydb.sqlite3?vfs=opfs";
    readonly tables: {
        readonly test: {
            readonly name: "test_table";
            readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
        };
    };
}databaseConfig = {
  filename: "file:mydb.sqlite3?vfs=opfs"filename: 'file:mydb.sqlite3?vfs=opfs',
  
tables: {
    readonly test: {
        readonly name: "test_table";
        readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
    };
}tables: {
    
test: {
    readonly name: "test_table";
    readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
}test: {
      name: "test_table"name: 'test_table',
      schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      "schema: `
        CREATE TABLE IF NOT EXISTS test_table (
          id INTEGER PRIMARY KEY AUTOINCREMENT,
          name TEXT NOT NULL,
          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        );
      `,
    },
  },
} as 
type const = {
    readonly filename: "file:mydb.sqlite3?vfs=opfs";
    readonly tables: {
        readonly test: {
            readonly name: "test_table";
            readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
        };
    };
}const

export function 
function useSQLite(): {
    isLoading: Ref<boolean, boolean>;
    error: Ref<Error | null, Error | null>;
    isInitialized: Ref<boolean, boolean>;
    executeQuery: (sql: string, params?: unknown[]) => Promise<...>;
}useSQLite() {
  const const isLoading: Ref<boolean, boolean>isLoading = ref<boolean>(value: boolean): Ref<boolean, boolean> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref(false)
  const const error: Ref<Error | null, Error | null>error = ref<Error | null>(value: Error | null): Ref<Error | null, Error | null> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref<Error | null>(null)
  const const isInitialized: Ref<boolean, boolean>isInitialized = ref<boolean>(value: boolean): Ref<boolean, boolean> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref(false)

  let let promiser: anypromiser: type ReturnType<T extends (...args: any) => any> = T extends (...args: any) => infer R ? R : any
Obtain the return type of a function typeReturnType<typeof import sqlite3Worker1Promisersqlite3Worker1Promiser> | null = null
  let let dbId: string | nulldbId: string | null = null

  async function function (local function) initialize(): Promise<boolean>initialize() {
    if (const isInitialized: Ref<boolean, boolean>isInitialized.Ref<boolean, boolean>.value: booleanvalue) return true

    const isLoading: Ref<boolean, boolean>isLoading.Ref<boolean, boolean>.value: booleanvalue = true
    const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Error | nullvalue = null

    try {
      // Initialize the SQLite worker
      let promiser: anypromiser = await new 
var Promise: PromiseConstructor
new <unknown>(executor: (resolve: (value: unknown) => void, reject: (reason?: any) => void) => void) => Promise<unknown>
Creates a new Promise.
@paramexecutor A callback used to initialize the promise. This callback is passed two arguments:
a resolve callback used to resolve the promise with a value or the result of another promise,
and a reject callback used to reject the promise with a provided reason or error.Promise((resolve: (value: unknown) => voidresolve) => {
        const const _promiser: any_promiser = import sqlite3Worker1Promisersqlite3Worker1Promiser({
          onready: () => voidonready: () => resolve: (value: unknown) => voidresolve(const _promiser: any_promiser),
        })
      })

      if (!let promiser: anypromiser) throw new 
var Error: ErrorConstructor
new (message?: string, options?: ErrorOptions) => Error (+1 overload)Error('Failed to initialize promiser')

      // Get configuration and open database
      await let promiser: anypromiser('config-get', {})
      const const openResponse: anyopenResponse = await let promiser: anypromiser('open', {
        filename: "file:mydb.sqlite3?vfs=opfs"filename: 
const databaseConfig: {
    readonly filename: "file:mydb.sqlite3?vfs=opfs";
    readonly tables: {
        readonly test: {
            readonly name: "test_table";
            readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
        };
    };
}databaseConfig.filename: "file:mydb.sqlite3?vfs=opfs"filename,
      })

      if (const openResponse: anyopenResponse.type === 'error') {
        throw new 
var Error: ErrorConstructor
new (message?: string, options?: ErrorOptions) => Error (+1 overload)Error(const openResponse: anyopenResponse.result.message)
      }

      let dbId: string | nulldbId = const openResponse: anyopenResponse.result.dbId as string

      // Create initial tables
      await let promiser: anypromiser('exec', {
        dbId: stringdbId,
        sql: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      "sql: 
const databaseConfig: {
    readonly filename: "file:mydb.sqlite3?vfs=opfs";
    readonly tables: {
        readonly test: {
            readonly name: "test_table";
            readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
        };
    };
}databaseConfig.
tables: {
    readonly test: {
        readonly name: "test_table";
        readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
    };
}tables.
test: {
    readonly name: "test_table";
    readonly schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      ";
}test.schema: "\n        CREATE TABLE IF NOT EXISTS test_table (\n          id INTEGER PRIMARY KEY AUTOINCREMENT,\n          name TEXT NOT NULL,\n          created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n        );\n      "schema,
      })

      const isInitialized: Ref<boolean, boolean>isInitialized.Ref<boolean, boolean>.value: booleanvalue = true
      return true
    }
    catch (function (local var) err: unknownerr) {
      const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Error | nullvalue = function (local var) err: unknownerr instanceof var Error: ErrorConstructorError ? function (local var) err: Errorerr : new 
var Error: ErrorConstructor
new (message?: string, options?: ErrorOptions) => Error (+1 overload)Error('Unknown error')
      throw const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Errorvalue
    }
    finally {
      const isLoading: Ref<boolean, boolean>isLoading.Ref<boolean, boolean>.value: booleanvalue = false
    }
  }

  async function function (local function) executeQuery(sql: string, params?: unknown[]): Promise<any>executeQuery(sql: stringsql: string, params: unknown[]params: unknown[] = []) {
    if (!let dbId: string | nulldbId || !let promiser: anypromiser) {
      await function (local function) initialize(): Promise<boolean>initialize()
    }

    const isLoading: Ref<boolean, boolean>isLoading.Ref<boolean, boolean>.value: booleanvalue = true
    const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Error | nullvalue = null

    try {
      const const result: anyresult = await let promiser: anypromiser!('exec', {
        dbId: DbIddbId: let dbId: string | nulldbId as import DbIdDbId,
        sql: stringsql,
        bind: unknown[]bind: params: unknown[]params,
        returnValue: stringreturnValue: 'resultRows',
      })

      if (const result: anyresult.type === 'error') {
        throw new 
var Error: ErrorConstructor
new (message?: string, options?: ErrorOptions) => Error (+1 overload)Error(const result: anyresult.result.message)
      }

      return const result: anyresult
    }
    catch (function (local var) err: unknownerr) {
      const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Error | nullvalue = function (local var) err: unknownerr instanceof var Error: ErrorConstructorError ? function (local var) err: Errorerr : new 
var Error: ErrorConstructor
new (message?: string, options?: ErrorOptions) => Error (+1 overload)Error('Query execution failed')
      throw const error: Ref<Error | null, Error | null>error.Ref<Error | null, Error | null>.value: Errorvalue
    }
    finally {
      const isLoading: Ref<boolean, boolean>isLoading.Ref<boolean, boolean>.value: booleanvalue = false
    }
  }

  return {
    isLoading: Ref<boolean, boolean>isLoading,
    error: Ref<Error | null, Error | null>error,
    isInitialized: Ref<boolean, boolean>isInitialized,
    executeQuery: (sql: string, params?: unknown[]) => Promise<any>executeQuery,
  }
}

Step 5: Create a SQLite Playground Component

Now let’s create a component to test our SQLite implementation:

<script setup lang="ts">
import { import useSQLiteuseSQLite } from '@/composables/useSQLite'
import { function ref<T>(value: T): [T] extends [Ref] ? IfAny<T, Ref<T>, T> : Ref<UnwrapRef<T>, UnwrapRef<T> | T> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref } from 'vue'

const { const isLoading: anyisLoading, const error: anyerror, const executeQuery: anyexecuteQuery } = import useSQLiteuseSQLite()
const const sqlQuery: Ref<string, string>sqlQuery = ref<string>(value: string): Ref<string, string> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref('SELECT * FROM test_table')
const const queryResult: Ref<any[], any[]>queryResult = ref<any[]>(value: any[]): Ref<any[], any[]> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref<any[]>([])
const const queryError: Ref<string | null, string | null>queryError = ref<string | null>(value: string | null): Ref<string | null, string | null> (+1 overload)
Takes an inner value and returns a reactive and mutable ref object, which
has a single property `.value` that points to the inner value.
@paramvalue - The object to wrap in the ref.@see{@link https://vuejs.org/api/reactivity-core.html#ref}ref<string | null>(null)

// Predefined example queries for testing
const 
const exampleQueries: {
    title: string;
    query: string;
}[]exampleQueries = [
  { title: stringtitle: 'Select all', query: stringquery: 'SELECT * FROM test_table' },
  { title: stringtitle: 'Insert', query: stringquery: "INSERT INTO test_table (name) VALUES ('New Test Item')" },
  { title: stringtitle: 'Update', query: stringquery: "UPDATE test_table SET name = 'Updated Item' WHERE name LIKE 'New%'" },
  { title: stringtitle: 'Delete', query: stringquery: "DELETE FROM test_table WHERE name = 'Updated Item'" },
]

async function function runQuery(): Promise<void>runQuery() {
  const queryError: Ref<string | null, string | null>queryError.Ref<string | null, string | null>.value: string | nullvalue = null
  const queryResult: Ref<any[], any[]>queryResult.Ref<any[], any[]>.value: any[]value = []

  try {
    const const result: anyresult = await const executeQuery: anyexecuteQuery(const sqlQuery: Ref<string, string>sqlQuery.Ref<string, string>.value: stringvalue)
    const const isSelect: booleanisSelect = const sqlQuery: Ref<string, string>sqlQuery.Ref<string, string>.value: stringvalue.String.trim(): string
Removes the leading and trailing white space and line terminator characters from a string.trim().String.toLowerCase(): string
Converts all the alphabetic characters in a string to lowercase.toLowerCase().String.startsWith(searchString: string, position?: number): boolean
Returns true if the sequence of elements of searchString converted to a String is the
same as the corresponding elements of this object (converted to a String) starting at
position. Otherwise returns false.startsWith('select')

    if (const isSelect: booleanisSelect) {
      const queryResult: Ref<any[], any[]>queryResult.Ref<any[], any[]>.value: any[]value = const result: anyresult?.result.resultRows || []
    }
    else {
      // After mutation, fetch updated data
      const queryResult: Ref<any[], any[]>queryResult.Ref<any[], any[]>.value: any[]value = (await const executeQuery: anyexecuteQuery('SELECT * FROM test_table'))?.result.resultRows || []
    }
  }
  catch (function (local var) err: unknownerr) {
    const queryError: Ref<string | null, string | null>queryError.Ref<string | null, string | null>.value: string | nullvalue = function (local var) err: unknownerr instanceof var Error: ErrorConstructorError ? function (local var) err: Errorerr.Error.message: stringmessage : 'An error occurred'
  }
}
</script>

<template>
  <div: HTMLAttributes & ReservedPropsdiv HTMLAttributes.class?: anyclass="max-w-7xl mx-auto px-4 py-6">
    <h2: HTMLAttributes & ReservedPropsh2 HTMLAttributes.class?: anyclass="text-2xl font-bold">SQLite Playground</h2: HTMLAttributes & ReservedPropsh2>

    <!-- Example queries -->
    <div: HTMLAttributes & ReservedPropsdiv HTMLAttributes.class?: anyclass="mt-4">
      <h3: HTMLAttributes & ReservedPropsh3 HTMLAttributes.class?: anyclass="text-sm font-medium">Example Queries:</h3: HTMLAttributes & ReservedPropsh3>
      <div: HTMLAttributes & ReservedPropsdiv HTMLAttributes.class?: anyclass="flex gap-2 mt-2">
        <button: ButtonHTMLAttributes & ReservedPropsbutton
          v-for="
const example: {
    title: string;
    query: string;
}example in 
const exampleQueries: {
    title: string;
    query: string;
}[]exampleQueries"
          key?: PropertyKey | undefined:key?: PropertyKey | undefinedkey="
const example: {
    title: string;
    query: string;
}example.title: stringtitle"
          HTMLAttributes.class?: anyclass="px-3 py-1 text-sm rounded-full bg-gray-100 hover:bg-gray-200"
          @onClick?: ((payload: MouseEvent) => void) | undefinedclick="const sqlQuery: Ref<string, string>sqlQuery = 
const example: {
    title: string;
    query: string;
}example.query: stringquery"
        >
          {{ 
const example: {
    title: string;
    query: string;
}example.title: stringtitle }}
        </button: ButtonHTMLAttributes & ReservedPropsbutton>
      </div: HTMLAttributes & ReservedPropsdiv>
    </div: HTMLAttributes & ReservedPropsdiv>

    <!-- Query input -->
    <div: HTMLAttributes & ReservedPropsdiv HTMLAttributes.class?: anyclass="mt-6">
      <textarea: TextareaHTMLAttributes & ReservedPropstextarea
        TextareaHTMLAttributes.value?: string | number | readonly string[] | null | undefinedv-model="const sqlQuery: Ref<string, string>sqlQuery"
        TextareaHTMLAttributes.rows?: Numberish | undefinedrows="4"
        HTMLAttributes.class?: anyclass="w-full px-4 py-3 rounded-lg font-mono text-sm"
        TextareaHTMLAttributes.disabled?: Booleanish | undefined:TextareaHTMLAttributes.disabled?: Booleanish | undefineddisabled="const isLoading: anyisLoading"
      />
      <button: ButtonHTMLAttributes & ReservedPropsbutton
        ButtonHTMLAttributes.disabled?: Booleanish | undefined:ButtonHTMLAttributes.disabled?: Booleanish | undefineddisabled="const isLoading: anyisLoading"
        HTMLAttributes.class?: anyclass="mt-2 px-4 py-2 rounded-lg bg-blue-600 text-white"
        @onClick?: ((payload: MouseEvent) => void) | undefinedclick="function runQuery(): Promise<void>runQuery"
      >
        {{ const isLoading: anyisLoading ? 'Running...' : 'Run Query' }}
      </button: ButtonHTMLAttributes & ReservedPropsbutton>
    </div: HTMLAttributes & ReservedPropsdiv>

    <!-- Error display -->
    <div: HTMLAttributes & ReservedPropsdiv
      v-if="const error: anyerror || const queryError: Ref<string | null, string | null>queryError"
      HTMLAttributes.class?: anyclass="mt-4 p-4 rounded-lg bg-red-50 text-red-600"
    >
      {{ const error: anyerror?.message || const queryError: Ref<string | null, string | null>queryError }}
    </div: HTMLAttributes & ReservedPropsdiv>

    <!-- Results table -->
    <div: HTMLAttributes & ReservedPropsdiv v-if="const queryResult: Ref<any[], any[]>queryResult.Array<any>.length: number
Gets or sets the length of the array. This is a number one higher than the highest index in the array.length" HTMLAttributes.class?: anyclass="mt-4">
      <h3: HTMLAttributes & ReservedPropsh3 HTMLAttributes.class?: anyclass="text-lg font-semibold">Results:</h3: HTMLAttributes & ReservedPropsh3>
      <div: HTMLAttributes & ReservedPropsdiv HTMLAttributes.class?: anyclass="mt-2 overflow-x-auto">
        <table: TableHTMLAttributes & ReservedPropstable HTMLAttributes.class?: anyclass="w-full">
          <thead: HTMLAttributes & ReservedPropsthead>
            <tr: HTMLAttributes & ReservedPropstr>
              <th: ThHTMLAttributes & ReservedPropsth
                v-for="const column: stringcolumn in var Object: ObjectConstructor
Provides functionality common to all JavaScript objects.Object.ObjectConstructor.keys(o: {}): string[] (+1 overload)
Returns the names of the enumerable string properties and methods of an object.
@paramo Object that contains the properties and methods. This can be an object that you created or an existing Document Object Model (DOM) object.keys(const queryResult: Ref<any[], any[]>queryResult[0])"
                key?: PropertyKey | undefined:key?: PropertyKey | undefinedkey="const column: stringcolumn"
                HTMLAttributes.class?: anyclass="px-4 py-2 text-left"
              >
                {{ const column: stringcolumn }}
              </th: ThHTMLAttributes & ReservedPropsth>
            </tr: HTMLAttributes & ReservedPropstr>
          </thead: HTMLAttributes & ReservedPropsthead>
          <tbody: HTMLAttributes & ReservedPropstbody>
            <tr: HTMLAttributes & ReservedPropstr
              v-for="(const row: anyrow, const index: numberindex) in const queryResult: Ref<any[], any[]>queryResult"
              key?: PropertyKey | undefined:key?: PropertyKey | undefinedkey="const index: numberindex"
            >
              <td: TdHTMLAttributes & ReservedPropstd
                v-for="const column: stringcolumn in var Object: ObjectConstructor
Provides functionality common to all JavaScript objects.Object.ObjectConstructor.keys(o: {}): string[] (+1 overload)
Returns the names of the enumerable string properties and methods of an object.
@paramo Object that contains the properties and methods. This can be an object that you created or an existing Document Object Model (DOM) object.keys(const row: anyrow)"
                key?: PropertyKey | undefined:key?: PropertyKey | undefinedkey="const column: stringcolumn"
                HTMLAttributes.class?: anyclass="px-4 py-2"
              >
                {{ const row: anyrow[const column: stringcolumn] }}
              </td: TdHTMLAttributes & ReservedPropstd>
            </tr: HTMLAttributes & ReservedPropstr>
          </tbody: HTMLAttributes & ReservedPropstbody>
        </table: TableHTMLAttributes & ReservedPropstable>
      </div: HTMLAttributes & ReservedPropsdiv>
    </div: HTMLAttributes & ReservedPropsdiv>
  </div: HTMLAttributes & ReservedPropsdiv>
</template>