3 years ago

Category: Database, Data

How I Learned to Stop Worrying and Love NULL in SQL You should not try to prevent NULL values - instead, write your query in a way to overcome its limitations.

Suppose you have an employee table containing columns such as EmployeeId, Name, ContactNumber and an alternate contact number.

If you try to perform an arithmetic operation, it also returns NULL because SQL cannot determine the correct value for the variable, and it considers an UNKNOWN value.

In this section, we will explore a few valuable functions to avoid getting undesirable values due to NULL.