Syntax:
column->path

In MySQL 5.7.9 and later, the -> operator serves as an alias for the
JSON_EXTRACT() function when used with two arguments, a column
identifier on the left and a JSON path on the right that is evaluated
against the JSON document (the column value). You can use such
expressions in place of column identifiers wherever they occur in SQL
statements.

URL: http://dev.mysql.com/doc/refman/5.7/en/json-search-functions.html

