Thank you for your prompt answer. I think I didn't explain what I want exactly. To add some explanation, At first, I would like to select by ID. If the ID has Tour = 'Yes'(s), it should be selected regardless of repeated number. (So, there could be 2 observation for A) If the ID doesn't have Tour = 'Yes', it should be presented as Tour = 'No' (I am not selecting Tour='Yes' only) If the observation has Tour='Yes' and Tour='No', I just need Tour = 'Yes' only. Briefly speaking, At least, per ID, there should be Tour = 'Yes' or Tour = 'No'. If it has Tour = 'Yes', I don't want the observation with Tour ='No'. And, I should check the number of Tour ='Yes', so the observation with Tour='Yes' should be selected. I appreciate your help.
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