[FLINK-30617] Wrong data type for null literal with cast in Hive dialect

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.16.0
• Fix Version/s: 1.17.0
• Component/s: Connectors / Hive
• Labels: pull-request-available
• Assignee: luoyuxia
• Reporter: luoyuxia
• Created: 10/Jan/23 10:36
• Updated: 16/Jan/23 09:29
• Resolved: 16/Jan/23 09:29

Description

When in hive dialect, it's found that the expression `cast null as bigint` will result in string type. Then it will cause the following sql fail:

create table t(a ARRAY<BIGINT>)
insert into t select array(cast(null as bigint)) 

The exception is:

org.apache.flink.table.api.ValidationException: Column types of query result and sink for 'test-catalog.default.t' do not match.
Cause: Incompatible types for sink column 'a' at position 0.Query schema: [_o__c0: ARRAY<STRING>]
Sink schema:  [a: ARRAY<BIGINT>] 

Introduce by FLINK-26474, after that we will fold `cast null as bigint` to `null `which will then considered as the null type. And for null type as argument, the function `array` will get a result type of array<string>. 

Issue Links

• links to: GitHub Pull Request #21642