To test for nulls, use only the comparison conditions IS NULL and IS NOT NULL. Any other comparison with nulls will result in NULL.

Keep in mind that an empty string is equivalent to a NULL literal.

## Noncompliant Code Example

    if var = null then
      -- code
    end if;

Or:

    if other_var = '' then
      -- code
    end if;

## Compliant Solution

    if var is null then
      -- code
    end if;

    if other_var is null then
      -- code
    end if;