I did some tracing of what commands that the Query Designer submits to SQL Server, and I found this batch:
DECLARE @edition sysname;
SET @edition = cast(SERVERPROPERTY(N'EDITION') as sysname);
SELECT case when @edition = N'SQL Azure' then 2 else 1 end as 'DatabaseEngineType',
SERVERPROPERTY('EngineEdition') AS DatabaseEngineEdition,
SERVERPROPERTY('ProductVersion') AS ProductVersion,
@@MICROSOFTVERSION AS MicrosoftVersion;
select host_platform from sys.dm_os_host_info
if @edition = N'SQL Azure'
select 'TCP' as ConnectionProtocol
else
exec ('select CONVERT(nvarchar(40),CONNECTIONPROPERTY(''net_transport'')) as ConnectionProtocol')
This fails on SQL Azure, because the DMV sys.dm_os_host_info is not available there.
Not that I understand why this batch is being submitted at all, but I guess they did not find it worth the effort fix this issue. And, in a way, I'm inclined to think that this is a good thing, because there are quite a few things that the Query Designer does not support, so it can more of a roadblock than a help.
But if you think that it should work, you can submit a suggestion here:
https://feedback.azure.com/d365community/forum/04fe6ee0-3b25-ec11-b6e6-000d3a4f0da0