[SPARK-36224] Use "void" as the type name of NullType

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 3.2.0
• Component/s: SQL
• Assignee: Linhong Liu
• Reporter: Linhong Liu
• Created: 20/Jul/21 08:09
• Updated: 02/Aug/21 15:20
• Resolved: 02/Aug/21 15:20

Description

In PR: https://github.com/apache/spark/pull/28833, we support parsing "void" as NullType. But still use "null" as the type name. This leads some confusing and inconsistent issues. For example:

`org.apache.spark.sql.types.DataType.fromDDL(NullType.toDDL)` is not working

Issue Links

• links to: [Github] Pull Request #33437 (linhongliu-db)