futoin-database

/* Installation: npm install futoin-asyncsteps futoin-executor futoin-invoker futoin-database sqlite3 (sqlite3 is an optional peer dependency for SQLite support that must be explicitly installed if you use it.) */ // Set environment variables for a test in-memory SQLite database. // In a real application, these would be set externally (e.g., .env file, Docker config). process.env.DB_TYPE = 'sqlite'; process.env.DB_PATH = ':memory:'; // Use an in-memory SQLite DB for quick demonstration process.env.DB_MAXCONN = '1'; process.env.FUTOIN_DB_ALIAS = 'my_sqlite_db'; // Custom alias for clarity const AsyncSteps = require('futoin-asyncsteps'); const Executor = require('futoin-executor'); // Required for ContainerConnectionManager const { AutoConfig } = require('futoin-database'); // Create a FutoIn Container Connection Manager (CCM) const ccm = new Executor.ContainerConnectionManager(); // Main execution block using AsyncSteps for flow control AsyncSteps((as) => { // 1. Auto-configure the database connection using environment variables. // The configuration object indicates supported types, and the last argument // is the alias under which the DB service will be registered in CCM. AutoConfig(as, ccm, { [process.env.FUTOIN_DB_ALIAS]: { type: ['sqlite'] } }, process.env.FUTOIN_DB_ALIAS); as.add((as) => { console.log(`Database service '${process.env.FUTOIN_DB_ALIAS}' configured.`); // 2. Get the database service instance from the CCM const db = ccm.get(process.env.FUTOIN_DB_ALIAS); // 3. Execute a simple query (Level 1 interface) console.log('\n--- Executing simple query (Level 1) ---'); db.query(as, 'SELECT ? + ? AS result_value', [10, 20]); as.add((as, rows) => { console.log('Query result:', rows); console.log('10 + 20 =', rows[0].result_value); // 4. Execute a multi-statement transaction (Level 2 interface) // This transaction creates a table, inserts data, and then selects it. // If any step fails, the entire transaction is rolled back. console.log('\n--- Executing transaction (Level 2) ---'); const tx = [ // Statement 0: Create table if not exists 'CREATE TABLE IF NOT EXISTS sample_users (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, email TEXT)', // Statement 1: Insert data for User A { query: 'INSERT INTO sample_users (name, email) VALUES (?, ?)', params: ['Charlie', 'charlie@example.com'] }, // Statement 2: Insert data for User B { query: 'INSERT INTO sample_users (name, email) VALUES (?, ?)', params: ['Diana', 'diana@example.com'] }, // Statement 3: Select data for User A by name { query: 'SELECT id, name, email FROM sample_users WHERE name = ?', params: ['Charlie'], expect: 'rows' }, // Statement 4: Select data for User B by email { query: 'SELECT id, name, email FROM sample_users WHERE email = ?', params: ['diana@example.com'], expect: 'rows' } ]; db.transaction(as, tx); as.add((as, results) => { console.log('Transaction results:'); // 'results' is an array where each element corresponds to the outcome of a statement in 'tx'. // For 'expect: rows', it will contain an array of row objects. console.log('Charlie data:', results[3][0]); // Result of statement 3 console.log('Diana data:', results[4][0]); // Result of statement 4 if (results[3][0].name === 'Charlie' && results[4][0].name === 'Diana') { console.log('Transaction successful: data inserted and retrieved correctly.'); } }); }); }); },(as, err) => { console.error('An error occurred during execution:', err.message); // Ensure connections are released on error ccm.release(); process.exit(1); }).whenEnd(() => { console.log('\nQuickstart execution complete. Releasing resources.'); // Ensure connections are released upon successful completion ccm.release(); process.exit(0); });