MongoDB provides quite a few aggregation pipeline operators for working with dates. This includes operators that extract certain parts of dates, such as the year, month, day, etc.
There are also a couple of MongoDB methods that enable you to iterate through a cursor, and apply a JavaScript function. This therefore allows you to use JavaScript to extract date values and date parts, etc from a field.
This article presents 6 ways to return the year portion from a date in MongoDB.
Continue readingIn MongoDB, the $toUpper aggregation pipeline operator converts a string to uppercase and returns the result.
In MongoDB, the $toLower aggregation pipeline operator converts a string to lowercase and returns the result.
From MongoDB 4.4, you can use the $isNumber aggregation pipeline operator to check whether or not a value is a number.
It accepts any valid expression, and returns true if the expression is a number, false if it’s not.
The $replaceAll aggregation pipeline operator was introduced in MongoDB 4.4.
This operator replaces all instances of a search string in an input string with a replacement string and returns the result.
If the search string isn’t found, then $replaceAll returns the input string.
The $replaceOne aggregation pipeline operator was introduced in MongoDB 4.4.
This operator replaces the first instance of a search string in an input string with a replacement string and returns the result.
If the search string isn’t found, then $replaceOne returns the input string.
MongoDB 4.4 introduced the $last aggregation pipeline operator.
This operator returns the last element in an array.
Continue readingMongoDB 4.4 introduced the $first aggregation pipeline operator.
This operator returns the first element in an array.
Continue readingIn MongoDB, the $arrayElemAt aggregation pipeline operator returns the element at the specified array index.
It accepts two arguments;
From MongoDB 4.4, you can use the $bsonSize aggregation pipeline operator to return the size of a given document in bytes.
$bsonSize accepts any valid expression as long as it resolves to either an object or null.