need:
According to the poverty signs, the number of people under different standards is taken out, in the unit of district and county.
1 represents the population that has been lifted out of poverty; 2 represents the population that has returned to poverty; 3 represents the population that has not been lifted out of poverty
select t3.region_id as 'regionId', t3.region_name as 'regionName', count(case when t1.tricolor = 1 then 1 else null end ) as 'greenTotal', count(case when t1.tricolor = 2 then 1 else null end ) as 'yellowTotal', count(case when t1.tricolor = 3 then 1 else null end )as 'redTotal' from pa_household_member t1 left join pa_household t2 on t2.household_id = t1.household_id left join system_region t3 on t3.region_id = t2.area group by t2.area
A known:
count(1) counts a record count (null) as 0; use this feature for classification statistics. No need to write complex subqueries.
Key Points:
count is in case when ..... eg: count (case when ....end )
Results show:
