CREATE TABLE labevents (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, itemid NUMBER, charttime TIME, valuenum NUMBER, valueuom CLOB)
CREATE TABLE d_icd_procedures (row_id NUMBER, icd9_code CLOB, short_title CLOB, long_title CLOB)
CREATE TABLE diagnoses_icd (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icd9_code CLOB, charttime TIME)
CREATE TABLE d_icd_diagnoses (row_id NUMBER, icd9_code CLOB, short_title CLOB, long_title CLOB)
CREATE TABLE inputevents_cv (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icustay_id NUMBER, charttime TIME, itemid NUMBER, amount NUMBER)
CREATE TABLE cost (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, event_type CLOB, event_id NUMBER, chargetime TIME, cost NUMBER)
CREATE TABLE prescriptions (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, startdate TIME, enddate TIME, drug CLOB, dose_val_rx CLOB, dose_unit_rx CLOB, route CLOB)
CREATE TABLE icustays (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icustay_id NUMBER, first_careunit CLOB, last_careunit CLOB, first_wardid NUMBER, last_wardid NUMBER, intime TIME, outtime TIME)
CREATE TABLE outputevents (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icustay_id NUMBER, charttime TIME, itemid NUMBER, value NUMBER)
CREATE TABLE admissions (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, admittime TIME, dischtime TIME, admission_type CLOB, admission_location CLOB, discharge_location CLOB, insurance CLOB, language CLOB, marital_status CLOB, ethnicity CLOB, age NUMBER)
CREATE TABLE procedures_icd (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icd9_code CLOB, charttime TIME)
CREATE TABLE patients (row_id NUMBER, subject_id NUMBER, gender CLOB, dob TIME, dod TIME)
CREATE TABLE d_items (row_id NUMBER, itemid NUMBER, label CLOB, linksto CLOB)
CREATE TABLE transfers (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icustay_id NUMBER, eventtype CLOB, careunit CLOB, wardid NUMBER, intime TIME, outtime TIME)
CREATE TABLE chartevents (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, icustay_id NUMBER, itemid NUMBER, charttime TIME, valuenum NUMBER, valueuom CLOB)
CREATE TABLE d_labitems (row_id NUMBER, itemid NUMBER, label CLOB)
CREATE TABLE microbiologyevents (row_id NUMBER, subject_id NUMBER, hadm_id NUMBER, charttime TIME, spec_type_desc CLOB, org_name CLOB)

calculate the number of patients who received a periph nerve destruction procedure two or more times.
SELECT COUNT(DISTINCT t1.subject_id) FROM (SELECT admissions.subject_id, COUNT(*) AS c1 FROM procedures_icd JOIN admissions ON procedures_icd.hadm_id = admissions.hadm_id WHERE procedures_icd.icd9_code = (SELECT d_icd_procedures.icd9_code FROM d_icd_procedures WHERE d_icd_procedures.short_title = 'periph nerve destruction') GROUP BY admissions.subject_id) AS t1 WHERE t1.c1 >= 2
WITH "t1" AS (SELECT "admissions"."subject_id", COUNT(*) AS "c1" FROM "procedures_icd" JOIN "d_icd_procedures" ON "d_icd_procedures"."icd9_code" = "procedures_icd"."icd9_code" AND "d_icd_procedures"."short_title" = 'periph nerve destruction' JOIN "admissions" ON "admissions"."hadm_id" = "procedures_icd"."hadm_id" GROUP BY "admissions"."subject_id") SELECT COUNT(DISTINCT "t1"."subject_id") FROM "t1" "t1" WHERE "t1"."c1" >= 2