In MongoDB, the $switch aggregation pipeline operator evaluates a series of case expressions, and executes a specified expression only when a case expression evaluates to true.
Category: MongoDB
3 Ways to Remove a Value from an Array in MongoDB
MongoDB provides a few operators that enable you to remove values from arrays.
These include:
$pull$pullAll$pop
MongoDB $mergeObjects
In MongoDB, the $mergeObjects aggregation pipeline operator combines multiple documents into a single document.
2 Ways to Append a Value to an Array in MongoDB
If you have a collection of documents in MongoDB that contain arrays, you can add new values to those arrays if required.
Depending on your specific requirements, you can use the $push operator or the $addToSet operator.
MongoDB $isArray
In MongoDB you can use the $isArray aggregation pipeline operator to check whether or not a value is an array.
It accepts any valid expression, and returns true if the expression is an array, false if it’s not.
MongoDB $literal
In MongoDB, the $literal aggregation pipeline operator returns a value without parsing.
It accepts any valid expression, and returns the unparsed expression.
The $literal operator can be useful for when you have a value that MongoDB could inadvertently interpret as an expression, but you don’t want it to.
For example, if you have a monetary amount that includes a dollar sign, MongoDB might inadvertently interpret that as a field name. You can use $literal to prevent MongoDB from interpreting such expressions.
MongoDB $ln
In MongoDB, the $ln aggregation pipeline operator calculates the natural logarithm (ln) of a number and returns the result as a double.
MongoDB $log
In MongoDB, the $log aggregation pipeline operator calculates the log of a number in the specified base and returns the result as a double.
MongoDB $indexOfCP
In MongoDB, the $indexOfCP aggregation pipeline operator searches a string for an occurrence of a substring and returns the UTF code point index of the first occurrence.
The UTF code point index is zero-based (i.e. it starts at 0).
MongoDB $indexOfBytes
In MongoDB, the $indexOfBytes aggregation pipeline operator searches a string for an occurrence of a substring and returns the UTF-8 byte index of the first occurrence.
The UTF byte index is zero-based (i.e. it starts at 0).