Question

I have the following table: Table is: probe

probe

——ProbeID——TranscriptID—-

   2655       4555555
   2600       5454542
   2600       4543234
   2344       56595959

…etc

How do I count the probes per each transcript? Importantly, same probe can associate with more than one transcript.

I need the final output to be the actual number of probes. By that I mean, the Total number (i.e. 12340) and not the actual table with the probes.

Thank you!

Answer 1

If you want to count number of TranscriptID associated with each ProbeID you can use group by as:

SELECT ProbeID, count(*)
FROM tab
GROUP BY ProbeID;

And if you just want the count of distinct ProbeID you can do:

SELECT COUNT(DISTINCT ProbeID) 
FROM tab