The -> shortcut for JSON_EXTRACT() was introduced with MySQL 5.7. And now there is the unquoting extraction operator or ->> to simplify things again! Think of it as JSON_UNQUOTE wrapped around JSON EXTRACT. The following there queries produce the same output.
AggregationThe new JSON_ARRAYAGG() and JSON_OBJECTAGG() takes a column or column argument and crates an array or object.
Clear as mud?
Well, examine this example:
The two rows from table foo are combined to make a two element array.
The JSON_OBJECT() function takes pairs of columns, assumes they are a key/value pair, and combines them. Note that non-JSON columns and data from JSON columns can be combined, as well as literal strings.