Category: JavaScript Answers

Sometimes, we want to add dates to pm2 error logs with Node.js.

In this article, we’ll look at how to add dates to pm2 error logs with Node.js.

How to add dates to pm2 error logs with Node.js?

To add dates to pm2 error logs with Node.js, we can run pm2 with the `–log-date-format option.

For instance, we run

pm2 start app.js --log-date-format 'DD-MM HH:mm:ss.SSS'

to run pm2 to start app.js and add dates to the log by specifying the --log-date-format option to add a date to each log entry in format DD-MM HH:mm:ss.SSS.

DD-MM HH:mm:ss.SSS is a moment format date string with the date, month, houts, minutes, seconds and milliseconds in this order.

Conclusion

To add dates to pm2 error logs with Node.js, we can run pm2 with the `–log-date-format option.

Sometimes, we want to get the parent directory name in Node.js.

In this article, we’ll look at how to get the parent directory name in Node.js.

How to get the parent directory name in Node.js?

To get the parent directory name in Node.js, we can use the path.basename and path.dirname methods.

For instance, we write

path.basename(path.dirname(filename))

to get the folder name of the path of filename with path.dirname.

Then we call path.basename to get the parent folder path from the path string returned by path.dirname.

Conclusion

To get the parent directory name in Node.js, we can use the path.basename and path.dirname methods.

Sometimes, we want to protect the password field in MongoDB Mongoose so it won’t return in a query.

In this article, we’ll look at how to protect the password field in MongoDB Mongoose so it won’t return in a query.

How to protect the password field in MongoDB Mongoose so it won’t return in a query?

To protect the password field in MongoDB Mongoose so it won’t return in a query, we can set the select option to false on a field when we create the schema.

For instance, we write

const userSchema = new Schema({
  name: {
    type: String,
    required: false,
    minlength: 5
  },
  email: {
    type: String,
    required: true,
    minlength: 5
  },
  phone: String,
  password: {
    type: String,
    select: false
  },
})

to create the userSchema that has the password field set to type String.

And we add select and set it to false to prevent it from being returned in queries.

Conclusion

To protect the password field in MongoDB Mongoose so it won’t return in a query, we can set the select option to false on a field when we create the schema.

Sometimes, we want to modify the data returned by a Mongoose query in Node.js.

In this article, we’ll look at how to modify the data returned by a Mongoose query in Node.js.

How to modify the data returned by a Mongoose query in Node.js?

To modify the data returned by a Mongoose query in Node.js, we can call lean to make Mongoose return a plain object version of the query result that we can modify.

For instance, we write

Survey.findById(req.params.id).lean().exec((err, data) => {
  data.surveyQuestions.forEach((sq) => {
    Question.findById(sq.question, (err, q) => {
      sq.question = q;
    });
  });
});

to call lean after call findById to make the data in the exec callback a plain JavaScript object version of the query result.

We then loop through each item in data.surveyQuestions and set sq.question to q on each entry in the Question.findById callback.

Conclusion

To modify the data returned by a Mongoose query in Node.js, we can call lean to make Mongoose return a plain object version of the query result that we can modify.

Sometimes, we want to add connection pooling with Node.js and MySQL.

In this article, we’ll look at how to add connection pooling with Node.js and MySQL.

How to add connection pooling with Node.js and MySQL?

To add connection pooling with Node.js and MySQL, we call pool.getConnection to get a connection.

For instance, we write

const getConnection = (callback) => {
  pool.getConnection((err, connection) => {
    callback(err, connection);
  });
};

to define the getConnection function that takes the callback we want to call after the pool.getConnection is done.

We get the MySQL connection from the connection parameter.

And we call callback with the connection so we can use it elsewhere.

Then when we’re done, we call connection.release(); to release the connection.

Conclusion

To add connection pooling with Node.js and MySQL, we call pool.getConnection to get a connection.