SQL字符串地理學解析

Question

爲什麼這項工作

select geography::STGeomFromText('POINT(-77.010996 38.890358)',4326) 

但這並不

declare @Latitude decimal(9,6) = 38.890358 
declare @Longitude decimal(9,6) = -77.010996 

select geography::STGeomFromText('''POINT(' + 
cast(@Longitude as nvarchar(15)) + ' ' + 
cast(@Latitude as nvarchar(15)) +')''',4326) 

我缺少什麼，他們似乎有效的是同樣的事情。

Answer 1

擺脫在開始時額外的報價，並最終

declare @Latitude decimal(9,6) = 38.890358 
declare @Longitude decimal(9,6) = -77.010996 

select geography::STGeomFromText('POINT(' + 
cast(@Longitude as nvarchar(15)) + ' ' + 
cast(@Latitude as nvarchar(15)) +')',4326)