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我想創建一個函數來計算兩個經緯度點之間的距離;但是,CREATE FUNCTION正在打破功能體的END IF;
部分(通過刪除IF/ELSE/END
塊進行確認)。MySQL CREATE FUNCTION打破END如果
任何想法?我想保持M/KM的差異,以免在應用程序中添加計算。
DELIMITER $$
CREATE FUNCTION HAVERSINE
(
from_latitude DECIMAL(30, 15),
from_longitude DECIMAL(30, 15),
to_latitude DECIMAL(30, 15),
to_longitude DECIMAL(30, 15),
unit VARCHAR(20)
)
RETURNS DECIMAL(30, 15)
DETERMINISTIC
BEGIN
DECLARE radius DECIMAL(30, 5);
DECLARE distance DECIMAL(30, 15);
IF(unit = 'MILES') THEN SET radius = '3959';
ELSE IF(unit = 'KILOMETRES' OR unit = 'KM') THEN SET radius = '6371.3929';
ELSE SET radius = '3959';
END IF;
SET distance = (
radius *
ACOS(
COS(RADIANS(from_latitude)) *
COS(RADIANS(to_latitude)) *
COS(RADIANS(to_longitude) - RADIANS(from_longitude)) +
SIN(RADIANS(from_latitude)) *
SIN(RADIANS(to_latitide))
)
);
RETURN distance;
END