How do I use the tstats command to count field pairs?

Hello everybody, i want to count how often does a specific pair of src-dest appear... something like src, dest, count 10.10.10.10 11.11.11.11 3 10.10.10.10 11.11.11.12 1 10.10.10.10 11.11.11.13 12 I use following string | tstats summariesonly=true prestats=true count as boo from datamodel=Network_Traffic.All_Traffic where All_Traffic.x_src_zone="smth" All_Traffic.x_dest_zone="smth" by All_Traffic.x_src_zone All_Traffic.x_dest_zone| table All_Traffic.x_src_zone All_Traffic.x_dest_zone boo Unfortunately, the whole boo column is always empty