DBMS:
postgresql

Error:
org.postgresql.util.PSQLException: ERROR: function pg_catalog.date_part(unknown, unknown) is not unique
  Hint: Could not choose a best candidate function. You might need to add explicit type casts.
  Position: 817

SQL:
/************************************************************************
@file getPopnPrev.sql
************************************************************************/

with init_popn as (
select p.person_id, p.gender_concept_id, p.year_of_birth, min(EXTRACT(YEAR FROM o.observation_period_start_date)) startYear,
          case
          when max(EXTRACT(YEAR FROM o.observation_period_end_date)) > EXTRACT(YEAR FROM CURRENT_DATE) then 1900 --year in future, person will not be used
          else max(EXTRACT(YEAR FROM o.observation_period_end_date))
          end as endYear
        from cdm.person p
        join cdm.observation_period o
          on p.person_id = o.person_id
        group by p.person_id, p.gender_concept_id, p.year_of_birth
),
popn as (
  select distinct person_id
  from init_popn
  where endYear = (
					select max(endYear)
					from init_popn)
	and startYear - year_of_birth between  0 and 120
	and gender_concept_id in (8507,8532)
	and ((startYear between EXTRACT(YEAR FROM '19000101') and EXTRACT(YEAR FROM '39000101')) or (endYear between EXTRACT(YEAR FROM '19000101') and EXTRACT(YEAR FROM '39000101'))))
select cohCount*1.0/totCount popPrev
from (
      select  (select count(person_id)
                from popn) totCount,
              (select count(person_id)
                from popn p
                join results.cohort co
                  on p.person_id = co.subject_id
                    and cohort_definition_id = 45) cohCount) a


R version:
R version 3.6.2 (2019-12-12)

Platform:
x86_64-w64-mingw32

Attached base packages:
- stats
- graphics
- grDevices
- utils
- datasets
- methods
- base

Other attached packages:
- PatientLevelPrediction (3.0.8)
- Cyclops (2.0.2)
- FeatureExtraction (2.2.5)
- DatabaseConnector (2.4.2)
- SqlRender (1.6.3)
- PheValuator (1.0.2)
- data.table (1.12.8)
- stringr (1.4.0)
- dplyr (0.8.4)