docs.sheetjs.com/docz/docs/03-demos/07-data/01-websql.md

---
title: WebSQL and SQLite
pagination_prev: demos/desktop/index
pagination_next: demos/local/index
sidebar_custom_props:
  type: web
  sql: true
---

WebSQL is a popular SQL-based in-browser database available on Chrome.  In
practice, it is powered by SQLite, and most simple SQLite-compatible queries
work as-is in WebSQL.

The public demo <https://sheetjs.com/sql> generates a database from workbook.

## WebSQL Details

Importing data from spreadsheets is straightforward using the `generate_sql`
helper function from ["Generating Tables"](/docs/demos/data/sql#generating-tables).

The Web SQL Database API is callback-based.  The following snippet wraps
transactions in Promise objects:

```js
const db = openDatabase('sheetql', '1.0', 'SheetJS WebSQL Test', 2097152);
const stmts = generate_sql(ws, wsname);

// NOTE: tx.executeSql and db.transaction use callbacks. This wraps in Promises
for(var stmt of stmts) await new Promise((res, rej) => {
  db.transaction(tx =>
    tx.executeSql(stmt, [],
      (tx, data) => res(data), // if the query is successful, return the data
      (tx, err) => rej(err) // if the query fails, reject with the error
  ));
});
```

The result of a SQL SELECT statement is a `SQLResultSet`.  The `rows` property
is a `SQLResultSetRowList`.  It is an "array-like" structure that has `length`
and properties like `0`, `1`, etc.  However, this is not a real Array object!

A real Array can be created using `Array.from`:

```js
db.readTransaction(tx =>
  tx.executeSQL("SELECT * FROM DatabaseTable", [], (tx, data) => {
    // data.rows is "array-like", so `Array.from` can make it a real array
    const aoo = Array.from(data.rows);
    const ws = XLSX.utils.json_to_sheet(aoo);
    // ... perform an export here OR wrap in a Promise
  })
);
```

### Live Demo

:::note

This demo was last tested on 2023 February 26

:::

The following demo generates a database with 5 fixed SQL statements. Queries
can be changed in the Live Editor.  The WebSQL database can be inspected in the
"WebSQL" section of the "Application" Tab of Developer Tools:

![WebSQL view in Developer Tools](pathname:///files/websql.png)

```jsx live
function SheetQL() {
  const [out, setOut] = React.useState("");
  const queries = [
    'DROP TABLE IF EXISTS Presidents',
    'CREATE TABLE Presidents (Name TEXT, Idx REAL)',
    'INSERT INTO Presidents  (Name, Idx) VALUES ("Barack Obama", 44)',
    'INSERT INTO Presidents  (Name, Idx) VALUES ("Donald Trump", 45)',
    'INSERT INTO Presidents  (Name, Idx) VALUES ("Joseph Biden", 46)'
  ];
  const xport = React.useCallback(async() => {
    /* prep database */
    const db = openDatabase('sheetql', '1.0', 'SheetJS WebSQL Test', 2097152);

    for(var q of queries) await new Promise((res, rej) => {
      db.transaction((tx) => {
        tx.executeSql(q, [], (tx, data) => res(data), (tx, err) => rej(err));
      });
    });

    /* pull data and generate rows */
    db.readTransaction(tx => {
      tx.executeSql("SELECT * FROM Presidents", [], (tx, data) => {
        const aoo = Array.from(data.rows);
        setOut("QUERY RESULT:\n" + aoo.map(r => JSON.stringify(r)).join("\n") + "\n")
        const ws = XLSX.utils.json_to_sheet(aoo);
        const wb = XLSX.utils.book_new();
        XLSX.utils.book_append_sheet(wb, ws, "Presidents");
        XLSX.writeFile(wb, "SheetQL.xlsx");
      });
    });
  });
  return ( <pre>{out}<button onClick={xport}><b>Fetch!</b></button></pre> );
}
```

## Server-Side SQLite

Most platforms offer a simple way to query SQLite database files.

The following example shows how to query for each table in an SQLite database,
query for the data for each table, add each non-empty table to a workbook, and
export as XLSX.

[The Northwind database is available in SQLite form](https://raw.githubusercontent.com/jpwhite3/northwind-SQLite3/master/dist/northwind.db).

:::note

This demo was last tested on 2023 February 26

:::

### NodeJS

The **`better-sqlite3`** module provides a very simple API for working with
SQLite databases. `Statement#all` runs a prepared statement and returns an array
of JS objects.

0) [Download `northwind.db`](https://raw.githubusercontent.com/jpwhite3/northwind-SQLite3/master/dist/northwind.db).

1) Install the dependencies:

```bash
npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz better-sqlite3@8.1.0
```

2) Save the following to `node.mjs`:

```js title="node.mjs"
/* Load SQLite3 connector library */
import Database from "better-sqlite3";

/* Load SheetJS library */
import * as XLSX from 'xlsx';
import * as fs from 'fs';
XLSX.set_fs(fs);

/* Initialize database */
var db = Database("northwind.db");

/* Create new workbook */
var wb = XLSX.utils.book_new();

/* Get list of table names */
var sql = db.prepare("SELECT name FROM sqlite_master WHERE type='table'");
var result = sql.all();

/* Loop across each name */
result.forEach(function(row) {
  /* Get first 100K rows */
  var aoo = db.prepare("SELECT * FROM '" + row.name + "' LIMIT 100000").all();
  if(aoo.length > 0) {
    /* Create Worksheet from the row objects */
    var ws = XLSX.utils.json_to_sheet(aoo, {dense: true});
    /* Add to Workbook */
    XLSX.utils.book_append_sheet(wb, ws, row.name);
  }
});

/* Write File */
XLSX.writeFile(wb, "node.xlsx");
```

3) Run `node node.mjs` and open `node.xlsx`

### Bun

Bun ships with a built-in high-performance module `bun:sqlite`.

0) [Download `northwind.db`](https://raw.githubusercontent.com/jpwhite3/northwind-SQLite3/master/dist/northwind.db).

1) Install the dependencies:

```bash
npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
```

2) Save the following to `bun.mjs`:

```js title="bun.mjs"
/* Load SQLite3 connector library */
import { Database } from "bun:sqlite";

/* Load SheetJS library */
import * as XLSX from 'xlsx';
import * as fs from 'fs';
XLSX.set_fs(fs);

/* Initialize database */
var db = Database.open("northwind.db");

/* Create new workbook */
var wb = XLSX.utils.book_new();

/* Get list of table names */
var sql = db.prepare("SELECT name FROM sqlite_master WHERE type='table'");
var result = sql.all();

/* Loop across each name */
result.forEach(function(row) {
  /* Get first 100K rows */
  var aoo = db.prepare("SELECT * FROM '" + row.name + "' LIMIT 100000").all();
  if(aoo.length > 0) {
    /* Create Worksheet from the row objects */
    var ws = XLSX.utils.json_to_sheet(aoo, {dense: true});
    /* Add to Workbook */
    XLSX.utils.book_append_sheet(wb, ws, row.name);
  }
});

/* Write File */
XLSX.writeFile(wb, "bun.xlsx");
```

3) Run `bun bun.mjs` and open `bun.xlsx`

### Deno

Deno `sqlite` library returns raw arrays of arrays.

0) [Download `northwind.db`](https://raw.githubusercontent.com/jpwhite3/northwind-SQLite3/master/dist/northwind.db).

1) Save the following to `deno.ts`:

```ts title="deno.ts"
/* Load SQLite3 connector library */
import { DB } from "https://deno.land/x/sqlite/mod.ts";

/* Load SheetJS library */
// @deno-types="https://cdn.sheetjs.com/xlsx-latest/package/types/index.d.ts"
import * as XLSX from 'https://cdn.sheetjs.com/xlsx-latest/package/xlsx.mjs';

/* Initialize database */
var db = new DB("northwind.db");

/* Create new workbook */
var wb = XLSX.utils.book_new();

/* Get list of table names */
var sql = db.prepareQuery("SELECT name FROM sqlite_master WHERE type='table'");
var result = sql.all();
/* Loop across each name */
result.forEach(function(row) {
  /* Get first 100K rows */
  var query = db.prepareQuery("SELECT * FROM '" + row[0] + "' LIMIT 100000")
  var aoa = query.all();
  if(aoa.length > 0) {
    /* Create array of arrays */
    var data = [query.columns().map(x => x.name)].concat(aoa);
    /* Create Worksheet from the aoa */
    var ws = XLSX.utils.aoa_to_sheet(data, {dense: true});
    /* Add to Workbook */
    XLSX.utils.book_append_sheet(wb, ws, row[0]);
  }
});

/* Write File */
XLSX.writeFile(wb, "deno.xlsx");
```

2) Run `deno run --allow-read --allow-write deno.ts` and open `deno.xlsx`