Display blank space for a column as NULL in the HIVE table data

[#1]

I am trying to display a column in HIVE as 'NULL' whenever the source data has a blank space. I tried using the SET TBLPROPERTIES ('serialization.null.format'='\\N') and SET TBLPROPERTIES ('serialization.null.format'='') which did not work. Does anyone know how to resolve this? 

[#2]

@BIDEV3421 

This property is for the opposite of what you want. The value of this property is what hive shows when the source day has a null value.

I don't think there's a property to do what you want, but you can use an expression like the following in your select:

case when mycol = ' ' then NULL else mycol end

Cheers

Andre