Question

Which of the following queries will return all records from table T?

Cosmo · Accepted Answer

NULL values should be compared using IS NULL and IS NOT NULL operators.

Cosmo · Accepted Answer

SELECT * FROM T WHERE NULL IS NULL;

Cosmo · Answer

SELECT * FROM T WHERE NULL = NULL;

Cosmo · Answer

SELECT * FROM T WHERE NULL <> NULL;

Cosmo · Answer

SELECT * FROM T WHERE NULL != NULL;

Cosmo · Answer

SELECT * FROM T WHERE NULL IS NOT NULL;