[BEAM-11696] NULL values don't work correctly when implementing LOGICAL_AND aggregation function in ZetaSQL

• Type: Bug
• Status: Resolved
• Priority: P3
• Resolution: Not A Problem
• Fix Version/s: Not applicable
• Component/s: dsl-sql-zetasql
• Assignee: Kyle Weaver
• Reporter: Sonam Ramchand
• Created: 27/Jan/21 07:38
• Updated: 02/Feb/21 23:15
• Resolved: 02/Feb/21 19:00

Description

Reference: https://github.com/google/zetasql/blob/master/docs/functions-and-operators.md#logical_and 

Problems: 

After implementation, there is a problem:

• When input contains all null values:

SELECT LOGICAL_AND(a) AS logical_and FROM UNNEST([null, null, null]) AS a;

the output is:

No matching signature for aggregate function LOGICAL_AND for argument types: INT64. Supported signature: LOGICAL_AND(BOOL)  

         which is same behavior as of BigQuery console. Though, it should return null.

How to test: unit tests