Avoiding a double-lookup for an efficient search

[98123722]

A user is only allowed to log in from one of their AllowedPlatform:

userAllowedPlatform.csv

| User     | AllowedPlatform |
+----------+-----------------+
| Mike     | PC              |
+----------+-----------------+
| Mike     | iPad            |
+----------+-----------------+
| Andrew   | PC              |
+----------+-----------------+
| Jennifer | iPad            |
+----------+-----------------+
| Jennifer | iPhone          |

The following datasets shows all user activities:

| User     | PlatformUsed |
+----------+--------------+
| Mike     | PC           |
+----------+--------------+
| Mike     | iPad         |
+----------+--------------+
| Mike     | iPhone       |
+----------+--------------+
| Jennifer | iPad         |
+----------+--------------+
| John     | iPhone       |

To find out who uses a platform that's not AllowedPlatform, I run a simple lookup for Users in the dataset against userAllowedPlatform.csv:

index="userLogs" | lookup userAllowedPlatform.csv User AS User, AllowedPlatform as PlatformUsed OUTPUT AllowedPlatform as PlatformUsed_Violation | eval description=if(isnull(PlatformUsed),PlatformUsed_Violation,description) | where NOT len(PlatformUsed_Violation) >1

Which gives me ALL unmatching results:

| User | PlatformUsed_Lookup |
+------+---------------------+
| Mike | iPhone              |
+------+---------------------+
| John | iPhone              |

My goal is perform this but exclude entries that are not part of userAllowedPlatform.csv (John, in this case). I can take the above results and match them again against userAllowedPlatform.csv, this time to remove entries with users that are not in userAllowedPlatform.csv, but this seems to me inefficient and over-complicated.

Looking for a simple and efficient way of solving this.

[somesoni2 · Accepted solution]

Give this a try

index="userLogs" 
| lookup userAllowedPlatform.csv User AS User OUTPUT AllowedPlatform 
| eval description=if(isnull(PlatformUsed),AllowedPlatform,description) 
| where isnotnull(AllowedPlatform) AND AllowedPlatform!=PlaformUsed

[98123722]

Thanks! worked perfectly.