docs.sheetjs.com/docz/docs/04-getting-started/03-demos/10-database.md
2022-07-23 05:06:31 -04:00

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9 Databases

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SQLite

Most platforms offer a simple way to query .sqlite databases.

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. Download and expand the zip archive to reveal Northwind_large.sqlite

  1. Install the dependencies:
$ npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz better-sqlite3
  1. Save the following to node.mjs:
/* Load SQLite3 connector library */
import Database from "better-sqlite3";

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

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

/* 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");
  1. Run node node.mjs and open node.xlsx
  1. Install the dependencies:
$ npm i --save https://cdn.sheetjs.com/xlsx-latest/xlsx-latest.tgz
  1. Save the following to bun.mjs:
/* Load SQLite3 connector library */
import { Database } from "bun:sqlite";

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

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

/* 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");
  1. Run bun bun.mjs and open bun.xlsx