How to check for NULL or empty value in fql (fast search)?

Question

I want to check for null or empty field in fql query , I want to add condition to retrieve result when is column not equal empty or null, I've tried these ways :

     <Context>
     <QueryText language='en-US' type='FQL'>and(string("Text"),not(Column_Name:equals(" ")))
     </QueryText>
  </Context>


     <Context>
     <QueryText language='en-US' type='FQL'>and(string("Text"),filter(Column_Name:not(" ")))
     </QueryText>
  </Context>

I also tried "^$" regular expression instead of empty string , but doesn't work .

any ideas ??

score 0 · Answer 1 · answered Feb 01 '13 at 16:43

Think of the index as a key/value lookup. If you check the index of a regular (paper) book, there are no blank entries. I.e. there is no entry in the index that gives you all the pages containing . The search index works the same way. There is no way to query for an empty value.

A common technique is to initialize your fields with some default value like, NODATA. If the field is never written to, it contains NODATA and you know it is empty.

How to check for NULL or empty value in fql (fast search)?

1 Answers1