Database Connection Development Tutorials, Guides & Insights

• SQLAlchemy (especially when using the psycopg2 driver for PostgreSQL) requires the URI to be in the format postgresql+psycopg2://.
• This prefix specifies the dialect (postgresql) and the driver (psycopg2) explicitly, which SQLAlchemy uses to establish the connection.

Heroku's DATABASE_URL uses the older postgres:// scheme, which isn't compatible with the latest SQLAlchemy requirements. Starting with SQLAlchemy 1.4, postgres:// is considered deprecated and no longer supported. The explicit postgresql+psycopg2:// scheme is required.

// Insert data into the "accounts" table
const stmt = db.prepare('INSERT INTO accounts (private_key, address, decimalNumber, has_transactions) VALUES (?, ?, ?, ?)');

stmt.run('private_key_value', 'address_value', 'decimalNumber_value', 1, function(err) {
  if (err) {
    console.error('Error inserting data:', err.message);
  } else {
    console.log(`A row has been inserted with rowid ${this.lastID}`);
  }
});

stmt.finalize();

• db.prepare(): Prepares an SQL statement for execution.
• stmt.run(): Executes the prepared statement with the provided values.
• The ? placeholders are replaced by the corresponding values in order.
• In this example:
• 'private_key_value': Replace with the actual private key.
• 'address_value': Replace with the actual wallet address.
• 'decimalNumber_value': Replace with the actual decimal number or relevant value.
• 1: Represents true for the has_transactions boolean field (use 0 for false).
• this.lastID: Provides the row ID of the last inserted row.
• stmt.finalize(): Finalizes the statement, releasing resources.

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