Filter in Azure Data Factory for white spaces

I have to do a filter when a value contains just white spaces, but it does not work, I can get right data if the filter is different to white spaces, look:

Works: trim(ZIPCODE)!=''

Does not work (i need this): trim(ZIPCODE)==''

Thanks

Solution 1:

"trim" is to Remove leading and trailing whitespace from a string, and return the updated string.

You can use "replace" --> Replace a substring with the specified string, and return the updated string.

Example:

I have an array with values. ["hi","bye","cool","yep"]

First, when there are no white spaces.

Condition: @equals(replace(item(),' ',''),item())

Next, when values have spaces in them ["hi","bye ","co ol","yep"]