postgresql计算两点距离

下面两种方法：

select
ST_Distance(
ST_SetSRID(ST_MakePoint(115.97166453999147,28.716493914230423),4326)::geography,
ST_SetSRID(ST_MakePoint(106.00231199774656,29.719258550486572),4326)::geography
),
ST_Length(
ST_MakeLine(
ST_MakePoint(115.97166453999147,28.716493914230423),
ST_MakePoint(106.00231199774656,29.719258550486572)
)::geography
)