问题描述
当我运行以下sql脚本从Google地图获取纬度和经度时，我得到的结果很奇怪：
--Declare inpute/output variables
DECLARE @Address as varchar(100),@City as varchar(25),@State as varchar(2),@PostalCode as varchar(10),@Country varchar(40),@County varchar(40),@GPSLatitude numeric(18,9),@GPSLongitude numeric(18,@MapURL varchar(1024)
SET @Address = '333 W 35th St'
SET @City = 'Chicago'
SET @State = 'IL'
--Build the web API URL
DECLARE @URL varchar(MAX)
SET @URL = 'http://maps.google.com/maps/api/geocode/xml?sensor=false&address=' +
CASE WHEN @Address IS NOT NULL THEN @Address ELSE '' END +
CASE WHEN @City IS NOT NULL THEN ',' + @City ELSE '' END +
CASE WHEN @State IS NOT NULL THEN ',' + @State ELSE '' END +
CASE WHEN @PostalCode IS NOT NULL THEN ',' + @PostalCode ELSE '' END +
CASE WHEN @Country IS NOT NULL THEN ',' + @Country ELSE '' END
SET @URL = REPLACE(@URL,' ','+')
--Create the OAuth request
DECLARE @Response varchar(8000)
DECLARE @XML xml
DECLARE @Obj int
DECLARE @Result int
DECLARE @HTTPStatus int
DECLARE @ErrorMsg varchar(MAX)
EXEC @Result = sp_OACreate 'MSXML2.ServerXMLHttp',@Obj OUT
BEGIN TRY
EXEC @Result = sp_OAMethod @Obj,'open',NULL,'GET',@URL,false
EXEC @Result = sp_OAMethod @Obj,'setRequestHeader','Content-Type','application/x-www-form-urlencoded'
EXEC @Result = sp_OAMethod @Obj,send,''
EXEC @Result = sp_OAGetProperty @Obj,'status',@HTTPStatus OUT
EXEC @Result = sp_OAGetProperty @Obj,'responseXML.xml',@Response OUT
END TRY
BEGIN CATCH
SET @ErrorMsg = ERROR_MESSAGE()
END CATCH
EXEC @Result = sp_OADestroy @Obj
IF (@ErrorMsg IS NOT NULL) OR (@HTTPStatus <> 200)
BEGIN
SET @ErrorMsg = 'Error in spGeocode: ' + ISNULL(@ErrorMsg,'HTTP result is: ' + CAST(@HTTPStatus AS varchar(10)))
RAISERROR(@ErrorMsg,16,1,@HTTPStatus)
RETURN
END
--Capture the response
SET @XML = CAST(@Response AS XML)
SET @GPSLatitude = @XML.value('(/GeocodeResponse/result/geometry/location/lat) [1]','numeric(18,9)')
SET @GPSLongitude = @XML.value('(/GeocodeResponse/result/geometry/location/lng) [1]',9)')
SET @City = @XML.value('(/GeocodeResponse/result/address_component[type="locality"]/long_name) [1]','varchar(40)')
SET @State = @XML.value('(/GeocodeResponse/result/address_component[type="administrative_area_level_1"]/short_name) [1]','varchar(40)')
SET @PostalCode = @XML.value('(/GeocodeResponse/result/address_component[type="postal_code"]/long_name) [1]','varchar(20)')
SET @Country = @XML.value('(/GeocodeResponse/result/address_component[type="country"]/short_name) [1]','varchar(40)')
SET @County = @XML.value('(/GeocodeResponse/result/address_component[type="administrative_area_level_2"]/short_name) [1]','varchar(40)')
SET @Address =
ISNULL(@XML.value('(/GeocodeResponse/result/address_component[type="street_number"]/long_name) [1]','varchar(40)'),'???') + ' ' +
ISNULL(@XML.value('(/GeocodeResponse/result/address_component[type="route"]/long_name) [1]','???')
SET @MapURL = 'http://maps.google.com/maps?f=q&h1=en&q=' + CAST(@GPSLatitude AS varchar(20)) + '+' + CAST(@GPSLongitude AS varchar(20))
--Review the results
SELECT @Address,@City,@State,@PostalCode,@Country,@County,@GPSLatitude,@GPSLongitude,@MapURL
返回的结果集是：
??? ??? NULL NULL NULL NULL NULL NULL NULL NULL
为什么会收到此回复？
解决方法
收到NULL响应的原因是，您从Google取回的XML如下：
<?xml version="1.0"?>
<GeocodeResponse>
<status>REQUEST_DENIED</status>
<error_message>You must use an API key to authenticate each request to Google Maps Platform APIs. For additional information,please refer to http://g.co/dev/maps-no-account</error_message>
</GeocodeResponse>
即您没有向他们传递API密钥。
您可以通过运行以下命令来检查响应：
select @Response
尝试：
SET @URL = 'http://maps.google.com/maps/api/geocode/xml?key=YOUR_API_KEY&sensor=false&address=' +
CASE WHEN @Address IS NOT NULL THEN @Address ELSE '' END +
CASE WHEN @City IS NOT NULL THEN ',' + @City ELSE '' END +
CASE WHEN @State IS NOT NULL THEN ',' + @State ELSE '' END +
CASE WHEN @PostalCode IS NOT NULL THEN ',' + @PostalCode ELSE '' END +
CASE WHEN @Country IS NOT NULL THEN ',' + @Country ELSE '' END