sqlite4.js

SQLite4 library with support for opening and writing databases, prepared statements, and more. This SQLite library is in pure javascript (compiled with emscripten). Please note that SQLite4 is still in development, and isn't production-ready.

Usage no npm install needed!

<script type="module">
  import sqlite4Js from 'https://cdn.skypack.dev/sqlite4.js';
</script>

README

SQLite compiled to javascript

Build Status

This is an experimental build of SQLite4 to javascript. SQLite4 itself is itself still experimental and not well documented.

That said, this build seems to work well (except for the known bug listed below), and is much faster than SQLite3. On my computer, it loads faster, and runs at least 3 times faster than sqlite3.

sql.js is a port of SQLite to JavaScript, by compiling the SQLite C code with Emscripten. no C bindings or node-gyp compilation here.

SQLite is public domain, sql.js is MIT licensed.

Known Bugs

  • Database.export() returns an empty file (a large Uint8Array containing only zeroes)

Usage

var sql = require('./js/sql-api.js');
// or sql = window.SQL if you are in a browser

// Create a database
var db = new sql.Database();
// NOTE: You can also use new sql.Database(data) where
// data is an Uint8Array representing an SQLite database file

// Execute some sql
sqlstr = "CREATE TABLE hello (a int, b char);";
sqlstr += "INSERT INTO hello VALUES (0, 'hello');"
sqlstr += "INSERT INTO hello VALUES (1, 'world');"
db.run(sqlstr); // Run the query without returning anything

var res = db.exec("SELECT * FROM hello");
/*
[
    {columns:['a','b'], values:[[0,'hello'],[1,'world']]}
]
*/

// Prepare an sql statement
var stmt = db.prepare("SELECT * FROM hello WHERE a=:aval AND b=:bval");

// Bind values to the parameters and fetch the results of the query
var result = stmt.getAsObject({':aval' : 1, ':bval' : 'world'});
console.log(result); // Will print {a:1, b:'world'}

// Bind other values
stmt.bind([0, 'hello']);
while (stmt.step()) console.log(stmt.get()); // Will print [0, 'hello']

// free the memory used by the statement
stmt.free();
// You can not use your statement anymore once it has been freed.
// But not freeing your statements causes memory leaks. You don't want that.

// Export the database to an Uint8Array containing the SQLite database file
var binaryArray = db.export();

Demo

There is an online demo available here : http://lovasoa.github.io/sql.js/GUI

Exemples

The test files provide up to date example of the use of the api.

Inside the browser

Example HTML file:

<script src='js/sql.js'></script>
<script>
    //Create the database
    var db = new SQL.Database();
    // Run a query without reading the results
    db.run("CREATE TABLE test (col1, col2);");
    // Insert two rows: (1,111) and (2,222)
    db.run("INSERT INTO test VALUES (?,?), (?,?)", [1,111,2,222]);

    // Prepare a statement
    var stmt = db.prepare("SELECT * FROM test WHERE a BETWEEN $start AND $end");
    stmt.getAsObject({$start:1, $end:1}); // {col1:1, col2:111}

    // Bind new values
    stmt.bind({$start:1, $end:2});
    while(stmt.step()) { //
        var row = stmt.getAsObject();
        // [...] do something with the row of result
    }
</script>

Creating a database from a file choosen by the user

SQL.Database constructor takes an array of integer representing a database file as an optional parameter. The following code uses an HTML input as the source for loading a database:

dbFileElm.onchange = function() {
    var f = dbFileElm.files[0];
    var r = new FileReader();
    r.onload = function() {
        var Uints = new Uint8Array(r.result);
        db = new SQL.Database(Uints);
    }
    r.readAsArrayBuffer(f);
}

See : http://lovasoa.github.io/sql.js/GUI/gui.js

Use from node.js

sql.js is hosted on npm. To install it, you can simply run npm install sql.js. Alternatively, you can simply download the file sql.js, from the download link below.

read a database from the disk:

var fs = require('fs');
var SQL = require('sql.js');
var filebuffer = fs.readFileSync('test.sqlite');

// Load the db
var db = new SQL.Database(filebuffer);

Write a database to the disk

You need to convert the result of db.export to a buffer

var fs = require("fs");
// [...] (create the database)
var data = db.export();
var buffer = new Buffer(data);
fs.writeFileSync("filename.sqlite", buffer);

See : https://github.com/lovasoa/sql.js/blob/master/test/test_node_file.js

Use as web worker

If you don't want to run CPU-intensive SQL queries in your main application thread, you can use the more limited WebWorker API.

You will need to download worker.sql.js

Example:

<script>
var worker = new Worker("js/worker.sql.js"); // You can find worker.sql.js in this repo
worker.onmessage = function() {
    console.log("Database opened");
    worker.onmessage = function(event){
        console.log(event.data); // The result of the query
    };
    worker.postMessage({
        id: 2,
        action: 'exec',
        sql: 'SELECT * FROM test'
    });
};

worker.onerror = function(e) {console.log("Worker error: ", e)};
worker.postMessage({
    id:1,
    action:'open',
    buffer:buf, /*Optional. An ArrayBuffer representing an SQLite Database file*/
});
</script>

See : https://github.com/lovasoa/sql.js/blob/master/test/test_worker.js

Documentation

The API is fully documented here : http://lovasoa.github.io/sql.js/documentation/

Download

You can download sql.js here : http://lovasoa.github.io/sql.js/js/sql.js And the Web Worker version: http://lovasoa.github.io/sql.js/js/worker.sql.js

Differences from the original sql.js

  • Support for BLOBs
  • Support for prepared statements
  • Cleaner API
  • More recent version of SQLite (3.8.4)
  • Compiled to asm.js (should be faster, at least on firefox)
  • Changed API. Results now have the form [{'columns':[], values:[]}]
  • Improved GUI of the demo. It now has :
    • syntax highlighting
    • nice HTML tables to display results
    • ability to load and save sqlite database files

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