I know in Oracle you can use DBA_TAB_COLUMNS (or ALL_TAB_COLUMNS). My SQL Server knowledge is very rusty, but can't you use the INFORMATION_SCHEMA.COLUMNS view?
SQL Server 2016 lets you treat JSON objects like rows in a table, allowing you to use data from AJAX queries in joins, updates and any other SQL statement you can think of. SQL Server 2016 provides ...