I apologize if this question isn't formatted correctly, I normally don't ask SQL questions. I have the following query created for my oracle database
SELECT * FROM X_METER_USE x
LEFT JOIN INSTRUMENTS i on x.ID_NUMBER = i.NAME and x.INST_SNR = 'INSTRUMENT'
LEFT JOIN STANDARD_REAGENT sr ON x.ID_NUMBER = sr.SAMPLE_NUMBER AND x.INST_SNR = 'SNR'
WHERE x.INST_SNR = 'SNR' AND sr.SAMPLE_NUMBER = i.NAME;
I would use
intersect as simplest way to check what you want
select * from X_METER_USE where project in ( SELECT x.project FROM X_METER_USE x INNER JOIN INSTRUMENTS i on x.ID_NUMBER = i.NAME where x.INST_SNR = 'INSTRUMENT' INTERSECT SELECT x.project FROM X_METER_USE x INNER JOIN STANDARD_REAGENT sr ON x.ID_NUMBER = sr.SAMPLE_NUMBER where x.INST_SNR = 'SNR' )