Comparison: Executing a Statement

This example compares how executing a statement works.

Without the Promise Helper Library, you need to provide a callback that handles the execution result. Code outside of the callback can’t tell when the execution is complete. Because of the way that callbacks work, code might not execute in the order you expect.

With the Promise Helper Library, you simply await the execution result.

Examples

tip

Click “WITHOUT Helper Library” to see the original code
Click “WITH Helper Library” to see the improved code using this library

WITHOUT Helper Library
WITH Helper Library

Adapted from an example in the Snowflake SDK documentation.

// Not using the Promise Helper Library

var statement = connection.execute({
  sqlText: 'CREATE DATABASE testdb',
  complete: function(err, stmt, rows) {
    if (err) {
      console.error(
        'Failed to execute statement due to the following error: ' +
        err.message
      );
    } else {
      console.log('Successfully executed statement: ' + stmt.getSqlText());
    }
  }
});

console.log(
  'This will likely execute before completion due to async behavior!'
);

// Using the Promise Helper Library

try {
  const { statement, resultsPromise } = await connection.execute({
    sqlText: 'CREATE DATABASE testdb',
  });
  await resultsPromise;
  console.log('Successfully executed statement: ' + statement.getSqlText());
} catch (err) {
  console.error(
    'Failed to execute statement due to the following error: ' +
    err.message
  );
}

console.log('This will execute after the promise resolves.');

Examples​

Examples