A table t(x) contains the values 1, NULL, 3, NULL, 5. What does the following query return?CREATE TABLE t(x INT); INSERT INTO t VALUES (1),…

A table t(x) contains the values 1, NULL, 3, NULL, 5. What does the following query return?

CREATE TABLE t(x INT);
INSERT INTO t VALUES (1),(NULL),(3),(NULL),(5);
SELECT COUNT(*), COUNT(x), SUM(x) FROM t;