Sql instead of insert trigger - insert data if does not exist -

i have following trigger on table redirects data , includes data 2 other tables based on left outer join.

if i.ndl_deviceid not exist in bbownermap column null fine.

what want is, if i.ndl_deviceid not exist in bbownermap want insert there , return resulting autonumber bbownermap.ownerid

trigger follows:-

alter trigger [dbo].[redirect]     on  [dbo].[ndl_dump]     instead of insert   begin  insert ndl_data (ndl_image,ndl_text,ndl_lat,ndl_lng,ndl_categoryid,ownerid)  select i.ndl_image,        i.ndl_text,        i.ndl_lat,        i.ndl_lng,        ndl_config.ndl_categoryid,        bbownermap.ownerid    inserted        left outer join        ndl_config        on i.ndl_category = ndl_config.ndl_categoryname        left outer join        bbownermap        on i.ndl_deviceid = bbownermap.deviceid end 

bbownermap table this:-

[dbo].[bbownermap](     [ownerid] [int] identity(1,1) not null,     [deviceid] [varchar](50) not null,     [devicenumber] [varchar](50) not null,  constraint [pk_bbownermap] primary key clustered  

any on how modify appreciated.

thanks.

you should able add insert statement @ top of trigger. remember inserted table can have more 1 row, dealing sets, not rows. code assumes sql server. left joins don't find matches, same not exists clause:

insert bbownermap (deviceid, devicenumber) select i.ndl_deviceid, <devicenum> inserted   left join bbownermap b on i.deviceid=b.deviceid b.ownerid null