instruction: how many patients were diagnosed with valve replacement < 7days within 2 months until 2 years ago after having been previously diagnosed with s/p bone marrow transplant?
response: SELECT COUNT(DISTINCT t1.uniquepid) FROM (SELECT patient.uniquepid, diagnosis.diagnosistime FROM diagnosis JOIN patient ON diagnosis.patientunitstayid = patient.patientunitstayid WHERE diagnosis.diagnosisname = 'valve replacement < 7days' AND DATETIME(diagnosis.diagnosistime) <= DATETIME(CURRENT_TIME(), '-2 year')) AS t1 JOIN (SELECT patient.uniquepid, diagnosis.diagnosistime FROM diagnosis JOIN patient ON diagnosis.patientunitstayid = patient.patientunitstayid WHERE diagnosis.diagnosisname = 's/p bone marrow transplant' AND DATETIME(diagnosis.diagnosistime) <= DATETIME(CURRENT_TIME(), '-2 year')) AS t2 WHERE t1.diagnosistime < t2.diagnosistime AND DATETIME(t2.diagnosistime) BETWEEN DATETIME(t1.diagnosistime) AND DATETIME(t1.diagnosistime, '+2 month')