CREATE TABLE table_train_172 ("id" NUMBER, "systolic_blood_pressure_sbp" NUMBER, "c_peptide_level" FLOAT, "hemoglobin_a1c_hba1c" FLOAT, "peak_stimulated_c_peptide" FLOAT, "diastolic_blood_pressure_dbp" NUMBER, "mixed_meal_tolerance_test_mmtt" BOOLEAN, "vitamin_d" NUMBER, "NOUSE" FLOAT)

undetectable c peptide ( c _ peptide < 0.1 ng / ml ) .
SELECT * FROM table_train_172 WHERE c_peptide_level < 0.1
SELECT * FROM "table_train_172" WHERE "c_peptide_level" < 0.1