Null Values

A field that has no value for a given object is null. Doradus treats null as a “value” that will not match any literal. For example, the clause Size=0 will be false if the Size field is null. This means that NOT(clause) will be true if clause references a null field.

For Boolean fields, this may be a little unintuitive: assume a Boolean field IsInternal is null for a given object. Then:

IsInternal=true // false

IsInternal=false // false

NOT IsInternal=true // true

NOT IsInternal=false // true

In other words, a null Boolean field is neither true nor false, so comparison to either value will always be false, and negating such a comparison will always be true.