Purpose
Use this function to determine if a value is null. You can call this function from the MapBasic window in MapInfo Pro.
Syntax
IsNull(expr)Return Value
Logical
Description
This function returns TRUE if the expression (expr) is a NULL value, else it returns FALSE.
Currently only the following types can contain a null value:
- Date
- Time
- DateTime
- Object
Example
select * from events where IsNull(event_date)The above statement return all records from the events table that have no value in the event_date column.