Introduction to MongoDB $rtrim Operator

The MongoDB $rtrim operator is used to remove specified characters from the end of a string. It can be combined with the $trim operator to remove spaces and other specified characters from both ends of a string.

Syntax

The syntax for the $rtrim operator is as follows:

{ $rtrim: { <field>: <character> } }

Here, <field> is the field to be modified, and <character> is the character to be removed from the end of the field.

Use cases

The $rtrim operator is useful for scenarios where you need to remove specific characters from the end of a string. For example, it can be used to remove file extensions or query parameters from a URL.

Example

The following example demonstrates how to use the $rtrim operator to remove specified characters from the end of a string.

Consider the following documents containing strings:

{ "_id": 1, "name": "John Smith##" }
{ "_id": 2, "name": "Mike Johnson###" }
{ "_id": 3, "name": "Sara Johnson#" }

The following example demonstrates how to use the $rtrim operator to remove the ‘#’ character from the end of the strings:

db.collection.updateMany({}, [
  { $set: { name: { $rtrim: { input: "$name", chars: "#" } } } }
])

After executing the above example operation, the documents containing the strings will be updated as follows:

{ "_id": 1, "name": "John Smith" }
{ "_id": 2, "name": "Mike Johnson" }
{ "_id": 3, "name": "Sara Johnson" }

Conclusion

The $rtrim operator is a very useful string manipulation operator that allows us to remove specified characters from the end of a string. It can be combined with the $trim operator to remove spaces and other specified characters from both ends of a string. When cleaning strings in documents, the $rtrim operator is a useful tool.