Replace column value with designated column if Value Empty

[andersenyunan]

Hi, I want to replace value in column with designated value in another column if found empty.

I use rule engine to help me on this, for instance:

This is my raw data:

Fruit	Class	Type
Apple	A	Glass
Orange	B
Melon	C
Apple	D	Bottle
Orange	E

This is my desired output if found empty:

Fruit	Class	Type
Apple	A	Glass
Orange	B	B
Melon	C	C
Apple	D	Bottle
Orange	E	E

I use rule engine with expression:
MISSING $Type$ => $Class$
TRUE => $Class$

but the output always replace all type column to class column value

Is there anything I did wrong?
Thanks!

[tommy]

Hi @andersenyunan,

looks like only one small adjustment of your rule

MISSING $Type$ => $Class$
TRUE => $Type$

Hope this helps, Greetz, Tommy

[andersenyunan]

Hi @tommy

Thanks for the correction Initially I thought that it didn’t work but somehow realized that I my column was not “?” and need to change it to “?” in order the rule to work