In MongoDB, when you update documents that contain arrays, you have the option of using the arrayFilters parameter.
The arrayFilters parameter allows you to specify an array of filter documents that determine which array elements to modify.
In the update document, use the $[<identifier>] filtered positional operator, which identifies the array elements that match the arrayFilters conditions for the update operation.
In MySQL, the JSON_ARRAY_INSERT() function is used to insert a new value into an array.
You provide the JSON document as the first argument, followed by the path to insert into, followed by the value to insert.
When using JSON documents with MySQL, we can use the JSON_ARRAY_APPEND() function to append new values to an array.
The way it works is, you provide the JSON document as the first argument, then follow that up with the path to append to, followed by the value to append.
In MySQL 5.7, this function was called JSON_APPEND() but that name is no longer supported.
In MySQL, you can use the JSON_ARRAY() function to create a JSON array from a list of values. You provide each value as a separate argument. Each argument becomes a separate element of the array.
The function also accepts an empty list (i.e. you provide no arguments). In this case, you’ll get an empty array.
Among the many MySQL aggregate functions is one called JSON_ARRAYAGG(). This function enables you to aggregate a result set as a single JSON array. Each row of the result set ends up as a single element in the array.
The order of the elements in the array is undefined.