[SPARK-19910] `stack` should not reject NULL values due to type mismatch

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0, 2.0.1, 2.1.0, 2.1.1
• Fix Version/s: 2.3.0
• Component/s: SQL
• Assignee: Dongjoon Hyun
• Reporter: Dongjoon Hyun
• Created: 10/Mar/17 20:57
• Updated: 13/Jun/17 04:19
• Resolved: 13/Jun/17 04:19

Description

Since `stack` function generates a table with nullable columns, it should allow mixed null values.

scala> sql("select stack(3, 1, 2, 3)").printSchema
root
 |-- col0: integer (nullable = true)

scala> sql("select stack(3, 1, 2, null)").printSchema
org.apache.spark.sql.AnalysisException: cannot resolve 'stack(3, 1, 2, NULL)' due to data type mismatch: Argument 1 (IntegerType) != Argument 3 (NullType); line 1 pos 7;
'Project [unresolvedalias(stack(3, 1, 2, null), None)]
+- OneRowRelation$

Issue Links

• links to: [Github] Pull Request #17251 (dongjoon-hyun)