[CALCITE-5884] ARRAY_TO_STRING function should return NULL if its 'nullValue' argument is NULL

• Type: Bug
• Status: Closed
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 1.35.0
• Fix Version/s: 1.36.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Mihai Budiu
• Reporter: Mihai Budiu
• Created: 01/Aug/23 21:35
• Updated: 10/Nov/23 11:34
• Resolved: 06/Nov/23 04:41

Description

This is the current definition of the function ARRAY_TO_STRING in SqlLibraryOperators:

  /** The "ARRAY_TO_STRING(array, delimiter [, nullText ])" function. */
  @LibraryOperator(libraries = {BIG_QUERY})
  public static final SqlFunction ARRAY_TO_STRING =
      SqlBasicFunction.create(SqlKind.ARRAY_TO_STRING,
          ReturnTypes.VARCHAR_NULLABLE,
          OperandTypes.STRING_ARRAY_CHARACTER_OPTIONAL_CHARACTER);

So the result is nullable if any of the arguments is nullable. However, the nullability of the last argument does not influence the result nullabillity: a NULL value for the third optional argument will not cause a NULL value to be output.

Issue Links

• links to: GitHub Pull Request #3346