javascript - Commit/rollback a knex transaction using async/await

Javascript - Commit/rollback a knex transaction using async/await

To commit or rollback a Knex transaction using async/await, you can follow these steps. Knex transactions are typically managed asynchronously in Node.js, and async/await provides a convenient way to handle asynchronous operations cleanly. Here's how you can commit or rollback transactions using Knex with async/await:

Setting up Knex and a Transaction

Assume you have already configured Knex and have a connection to your database. Here's a simplified example:

const knex = require('knex')({
  client: 'mysql',
  connection: {
    host: 'your_database_host',
    user: 'your_database_user',
    password: 'your_database_password',
    database: 'your_database_name'
  }
});

async function performTransaction() {
  try {
    // Start a transaction
    const trx = await knex.transaction();

    // Example query within the transaction
    await trx('users').where({ id: 1 }).update({ active: true });

    // Commit the transaction
    await trx.commit();
    console.log('Transaction committed successfully.');
  } catch (error) {
    // Rollback on error
    await trx.rollback();
    console.error('Transaction failed and rolled back.', error);
  }
}

Explanation:

  1. Starting a Transaction: Use knex.transaction() to start a transaction. This function returns a promise that resolves to a transaction object (trx).

  2. Performing Operations: Execute Knex queries within the transaction (trx). These queries will be part of the transaction until it is committed or rolled back.

  3. Committing a Transaction: Use trx.commit() to commit the transaction. This operation should be performed after all operations within the transaction are successful.

  4. Rolling Back on Error: If an error occurs during the transaction, catch the error and use trx.rollback() to roll back any changes made within the transaction. This ensures that the database remains consistent.

Example with Error Handling:

async function performTransaction() {
  let trx;
  try {
    trx = await knex.transaction();

    await trx('users').where({ id: 1 }).update({ active: true });

    // Simulate an error
    throw new Error('Simulated error');

    await trx.commit();
    console.log('Transaction committed successfully.');
  } catch (error) {
    if (trx) {
      await trx.rollback();
    }
    console.error('Transaction failed and rolled back.', error);
  }
}

Notes:

  • Transaction Scope: All operations (update, insert, delete, etc.) within the trx object are part of the same transaction until committed or rolled back.

  • Error Handling: Always ensure to handle errors properly and rollback transactions on error to maintain data integrity.

  • Connection Management: Knex manages connections and transactions internally. Each transaction gets its own connection, which is automatically released after commit or rollback.

By using async/await with Knex transactions, you can ensure that database operations are atomic and consistent, while also handling errors effectively. Adjust the queries and error handling as per your application's specific requirements and business logic.

Examples

  1. Knex Transaction with Async/Await: Commit Example

    Description: Perform database operations within a Knex transaction using async/await and commit the transaction on success.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    try {
        await knex.transaction(async (trx) => {
            // Perform database operations within the transaction
            await trx('table1').insert({ id: 1, name: 'Item 1' });
            await trx('table2').insert({ id: 1, value: 'Value 1' });
        });
        console.log('Transaction committed successfully.');
    } catch (error) {
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  2. Knex Transaction Rollback with Async/Await

    Description: Implement a Knex transaction using async/await and rollback the transaction on error.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    try {
        await knex.transaction(async (trx) => {
            // Perform database operations within the transaction
            await trx('table1').insert({ id: 1, name: 'Item 1' });
            await trx('table2').insert({ id: 1, value: 'Value 1' });
            // Simulate an error condition
            throw new Error('Rollback transaction');
        });
        console.log('Transaction committed successfully.');
    } catch (error) {
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  3. Using Async/Await with Knex Transaction and Commit

    Description: Demonstrate how to use async/await with Knex transaction to commit changes to the database.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    let trx;
    try {
        trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        await trx.commit();
        console.log('Transaction committed successfully.');
    } catch (error) {
        if (trx) {
            await trx.rollback();
        }
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  4. Knex Transaction with Async/Await: Rollback Example

    Description: Implement a Knex transaction using async/await and rollback explicitly on error.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    let trx;
    try {
        trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        // Simulate an error condition
        throw new Error('Rollback transaction');
    } catch (error) {
        if (trx) {
            await trx.rollback();
        }
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  5. Handle Knex Transaction Commit with Async/Await

    Description: Handle Knex transaction commit and rollback using async/await for better control over database transactions.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    let trx;
    try {
        trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        await trx.commit();
        console.log('Transaction committed successfully.');
    } catch (error) {
        if (trx) {
            await trx.rollback();
        }
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  6. Knex Transaction Commit and Rollback Handling with Async/Await

    Description: Implement commit and rollback handling for Knex transactions using async/await for improved error handling.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    let trx;
    try {
        trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        await trx.commit();
        console.log('Transaction committed successfully.');
    } catch (error) {
        console.error('Error committing transaction:', error);
        if (trx) {
            await trx.rollback();
        }
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  7. Async/Await Knex Transaction with Commit

    Description: Use async/await syntax to manage Knex transactions including commit operation.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    try {
        const trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        await trx.commit();
        console.log('Transaction committed successfully.');
    } catch (error) {
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  8. Using Knex Transaction and Async/Await: Rollback on Error

    Description: Handle Knex transaction rollback using async/await when an error occurs during database operations.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    try {
        const trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        // Simulate an error condition
        throw new Error('Rollback transaction');
    } catch (error) {
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  9. Knex Transaction Commit and Rollback Handling

    Description: Implement commit and rollback handling for Knex transactions using async/await for error management.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    try {
        const trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        await trx.commit();
        console.log('Transaction committed successfully.');
    } catch (error) {
        console.error('Error committing transaction:', error);
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

  10. Async/Await Knex Transaction: Rollback on Error

    Description: Use async/await syntax with Knex transactions and rollback explicitly on error.

    const knex = require('knex')(knexConfig);

async function performTransaction() {
    let trx;
    try {
        trx = await knex.transaction();
        await trx('table1').insert({ id: 1, name: 'Item 1' });
        await trx('table2').insert({ id: 1, value: 'Value 1' });
        // Simulate an error condition
        throw new Error('Rollback transaction');
    } catch (error) {
        console.error('Error committing transaction:', error);
        if (trx) {
            await trx.rollback();
        }
    } finally {
        await knex.destroy(); // Close the connection pool
    }
}

performTransaction();

More Tags

text-align coldfusion http-status-code-500 string-length yaml firebase-tools local laravel-middleware debouncing .htaccess

More Programming Questions

More Trees & Forestry Calculators

More Fitness-Health Calculators

More Everyday Utility Calculators

More Chemical reactions Calculators