As you can see in the image, while including the expression I’m seeing a error like “column doesn’t exist” even though i created the required columns earlier in the same table. please let me know the way to fix it. Thanks in advance
Hello!
It’s probably that names with special characters are not recognized. You can try writing your column names in camelCase format, and then reference it as you did. Like this:
Example:
Result:
I hope it helps. If you have any doubts, you can reply me 
Yeah , thank you i will try it.