MongoDB, the $strLenBytes aggregation pipeline operator returns the number of UTF-8 encoded bytes in the specified string.
Each character in a string can contain contain a different number of bytes, depending on the character being used. The $strLenBytes operator can figure out how many bytes each character contains and return the correct result for the whole string.
In MongoDB, the $stdDevPop aggregation pipeline operator calculates the population standard deviation of its input values.
The input values can be from a group of documents (i.e. documents that are grouped by the same key), or they can be multiple fields within a single document.
Continue readingIn MongoDB, the $stdDevSamp aggregation pipeline operator calculates the sample standard deviation of the input values.
The input values can be from a group of documents (i.e. documents that are grouped by the same key), or they can be multiple fields within a single document.
Continue readingIn MongoDB, the $strcasecmp aggregation pipeline operator performs a case-insensitive comparison of two strings.
It returns either 1, 0, or -1, depending on whether or not the first string is greater than, equal to, or less than the second string.
In MongoDB, the $split aggregation pipeline operator divides a string into an array of substrings based on a delimiter.
The delimiter is removed from the string, and the substrings are added as elements to the array.
To use $split, you specify the string and the delimiter.
If the delimiter isn’t found in the string, the original string is returned as the only item in the array.
Continue readingIn MongoDB, the $slice aggregation pipeline operator returns a subset of an array.
To use $slice, you specify the number of elements to return from the array. You can also specify a starting position for which to take the subset from the array.
In MongoDB, the $size aggregation pipeline operator counts and returns the total number of items in an array.
The $size operator accepts one argument. The argument can be any valid expression that resolves to an array.
In MongoDB, the $setUnion aggregation pipeline operator accepts two or more arrays and returns an array containing the elements that appear in any of those input arrays.
$setUnion accepts two or more arguments, all of which can be any valid expression as long as they each resolve to an array. $setUnion treats the arrays as sets.
In MongoDB, the $setIsSubset aggregation pipeline operator accepts two arrays and returns true when the first array is a subset of the second, and false when it isn’t.
The first array is also considered a subset when it equals the second array.
Continue readingIn MongoDB, the $setIntersection aggregation pipeline operator accepts two or more arrays and returns an array that contains the elements that appear in all input arrays.
$setIntersection accepts two or more arguments, all of which can be any valid expression as long as they each resolve to an array. $setIntersection treats the arrays as sets.