Alice Sherepa added a comment - 2019-11-14 15:49 - edited Thank you for the report! Reproducible on MariaDB 5.5-10.4 (and Mysql 5.6.40,5.7.26, but works correct in 8.0.16) MariaDB [test]> SELECT 5 from dual WHERE LEAST(1, NULL); +---+ | 5 | +---+ | 5 | +---+ 1 row in set (0.000 sec)   MariaDB [test]> SELECT LEAST(1, NULL); +----------------+ | LEAST(1, NULL) | +----------------+ | NULL | +----------------+ 1 row in set (0.000 sec)   MariaDB [test]> create table t0 (c0 int); Query OK, 0 rows affected (0.023 sec)   MariaDB [test]> insert into t0 values (1),(0),(null); Query OK, 3 rows affected (0.000 sec) Records: 3 Duplicates: 0 Warnings: 0   MariaDB [test]> SELECT * FROM t0 WHERE GREATEST(c0, NULL); +------+ | c0 | +------+ | 1 | +------+ 1 row in set (0.000 sec)

Alexander Barkov added a comment - 2024-04-22 14:30 The same problem is repeatable with the DOUBLE data type: CREATE OR REPLACE TABLE t0(c0 DOUBLE ); INSERT INTO t0 VALUES (1); SELECT * FROM t0 WHERE GREATEST(c0, NULL ); +------+ | c0 | +------+ | 1 | +------+