What are the differences between Null, Zero and Blank in SQL?

Question

Can someone please explain the differences between Null, Zero and Blank in SQL to me?

Answer 1

You may correlate NULL-BLANK-ZERO case by child birth scenario( A real life Example.).

NULL Case: Child is not born yet.

BLANK Case: Child is born but we didn't give any name to him

ZERO Case: We defined it as zero, Child is born but of zero age. See how this data will look in a database table:

Also NULL is a absence of value, where a field having NULL is not allocated any memory, where as empty fields have empty value with allocated space in memory.