[SPARK-23953] Add get_json_scalar function

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 2.3.0
• Component/s: SQL
• Assignee: Unassigned
• Reporter: Timothy Chen
• Created: 10/Apr/18 16:55
• Updated: 12/Apr/18 18:59
• Resolved: 12/Apr/18 18:59

Description

Besides get_json_object which returns a JSON string in a return type, we should add a function "get_json_scalar" that returns a scalar type assuming the path maps to a scalar (boolean, number, string or null). It returns null when the path points to a object or array structure

This is also in Presto (https://prestodb.io/docs/current/functions/json.html).