unique nulls [not] distinct

BigQueryDb2 (LUW)MariaDBMySQLOracle DBPostgreSQLSQL ServerSQLite20152017201920212023⊘ 3.5.7 - 3.50.0⊘ 2008R2 - 2022✓ 15 - 17⊘ 8.3 - 14⊘ 11gR1 - 23.9⊘ 5.0 - 9.3.0⊘ 5.1 - 12.0.2