--* lab_pos:
--*   attr:
--*     fillcolor: '2'
--*   desc: Identifies the first date of any PCR/Ag lab positive result. Original code
--*     by Emily Pfaff.
--*   ext: sql
--*   inputs:
--*   - covid_tests
--*   - measurement_lda_pin
--*   - positive_words
--* 

SELECT m.person_id, min(m.measurement_date) as pos_test_idx
FROM Measurement_lda_pin m JOIN covid_tests p on m.measurement_concept_id = p.concept_id
    JOIN positive_words pr on m.value_as_concept_id = pr.concept_id
GROUP BY m.person_id