(SQL Server) HTTP HEAD Request

Sends an HTTP HEAD request and gets the response.

Note: The response to an HTTP HEAD request is always just the response header. The reponse body is always 0 length (thus the reason it's called a "HEAD" request..)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @sTmp1 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @http int
    -- Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- If the URL uses "https://", then the connection will be TLS.
    -- Otherwise it will be TCP.
    DECLARE @resp int
    EXEC sp_OAMethod @http, 'GetHead', @resp OUT, 'https://example-code.com/'
    EXEC sp_OAGetProperty @http, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        -- A failure is when we don't get any response.  It could be a timeout, an inability to connect, etc.
        -- For example, a "404 Not Found" response is still a response, and thus deemed success in terms of the API..
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @http
        RETURN
      END

    -- Examine the response.

    EXEC sp_OAGetProperty @resp, 'StatusCode', @iTmp0 OUT
    PRINT 'Status Code = ' + @iTmp0

    EXEC sp_OAGetProperty @resp, 'StatusLine', @sTmp0 OUT
    PRINT 'Status Line = ' + @sTmp0

    EXEC sp_OAGetProperty @resp, 'StatusText', @sTmp0 OUT
    PRINT 'Status Text = ' + @sTmp0

    PRINT 'Full Response Header:'
    EXEC sp_OAGetProperty @resp, 'Header', @sTmp0 OUT
    PRINT @sTmp0

    PRINT '----'
    DECLARE @numHeaderFields int
    EXEC sp_OAGetProperty @resp, 'NumHeaderFields', @numHeaderFields OUT

    PRINT 'Num Header Fields: ' + @numHeaderFields
    DECLARE @i int

    SELECT @i = 0
    WHILE @i <= @numHeaderFields - 1
      BEGIN
        EXEC sp_OAMethod @resp, 'GetHeaderName', @sTmp0 OUT, @i

        EXEC sp_OAMethod @resp, 'GetHeaderValue', @sTmp1 OUT, @i
        PRINT @sTmp0 + ': ' + @sTmp1
        SELECT @i = @i + 1
      END

    EXEC @hr = sp_OADestroy @resp


    EXEC @hr = sp_OADestroy @http


END
GO