sqlite node | | Cell 1 | Search

The code imports Node.js modules for file system interactions (fs) and SQLite database interactions (sqlite3), and defines a database connection using a specified SQLite database file. It then reads and executes SQL commands from a separate file, passing the commands to the database instance for execution.

Cell 0

var fs = require('fs')
var path = require('path')
var sqlite3 = require('better-sqlite3')
var sauce = '/Users/briancullinan/Documents/studysauce3/db/studysauce.db'
var db = new sqlite3(sauce, {})
var cmds = fs.readFileSync('/Users/briancullinan/Documents/studysauce3/db/studysauce.sqlite')
    .toString()
db.transaction(cmds).run()

What the code could have been:

// Import required modules
const fs = require('fs').promises; // Use promises for asynchronous file operations
const path = require('path');
const sqlite3 = require('sqlite3');

// Define database file path
const DATABASE_FILE = path.join(
  '/Users/briancullinan/Documents/studysauce3/db',
 'studysauce.db'
);

// Initialize SQLite database connection
async function createDatabaseConnection() {
  // Check if database file exists, create it if not
  try {
    await fs.access(DATABASE_FILE);
  } catch (err) {
    await fs.mkdir(path.dirname(DATABASE_FILE), { recursive: true });
    await fs.writeFile(DATABASE_FILE, '');
  }
  return new sqlite3.Database(DATABASE_FILE);
}

// Read SQL commands from file
async function getSQLCommands() {
  // Use try-catch block to handle file reading errors
  try {
    const commands = await fs.readFile(
      path.join('/Users/briancullinan/Documents/studysauce3/db','studysauce.sqlite'),
      'utf8'
    );
    return commands;
  } catch (err) {
    console.error(`Error reading SQL commands: ${err}`);
    return '';
  }
}

// Execute SQL commands in database
async function executeCommands(db, commands) {
  // Use transaction to execute multiple commands
  await db.exec(commands);
  // TODO: Handle errors and exceptions
}

// Main function to create database connection and execute SQL commands
async function main() {
  try {
    const db = await createDatabaseConnection();
    const commands = await getSQLCommands();
    await executeCommands(db, commands);
    console.log('SQL commands executed successfully');
  } catch (err) {
    console.error(`Error executing SQL commands: ${err}`);
  } finally {
    // Close database connection
    db.close();
  }
}

main();

Code Breakdown

Importing Node.js Modules

var fs = require('fs')
var path = require('path')
var sqlite3 = require('better-sqlite3')

The code imports three Node.js modules:

Defining Database Connection

var sauce = '/Users/briancullinan/Documents/studysauce3/db/studysauce.db'
var db = new sqlite3(sauce, {})

The code defines a variable sauce with the path to a SQLite database file and creates a new instance of the sqlite3 module, passing the database path and an empty options object to connect to the database.

Reading and Executing SQL Commands

var cmds = fs.readFileSync('/Users/briancullinan/Documents/studysauce3/db/studysauce.sqlite')
   .toString()
db.transaction(cmds).run()

The code: