PostgreSQL/PostGIS計數訪問次數

Question

考慮到每天最多訪問次數爲1，即使車輛每天多次訪問該地點，我也需要統計車輛訪問兩個日期之間的地點的次數。

這裏是我寫的：

SELECT DISTINCT id_vehicle, datehour::date as dt, COUNT(id_vehicle) AS times 
FROM history 
WHERE datehour between '2017-01-01' AND CURRENT_TIMESTAMP AND 
     ST_Contains('POLYGON((x1 y1, x2 y2, x3 y3, x4 y4, x1 y1))',ST_MakePoint(longitude,latitude)) 
GROUP BY datehour::date, id_vehicle; 

結果我需要：

Answer 1

如果我理解正確的話，你想：

SELECT id_vehicle, COUNT(DISTINCT datehour::date) AS times 
FROM history 
WHERE datehour between '2017-01-01' AND CURRENT_TIMESTAMP AND 
     ST_Contains('POLYGON((x1 y1, x2 y2, x3 y3, x4 y4, x1 y1))', ST_MakePoint(longitude, latitude)) 
GROUP BY id_vehicle;