select a.*,b.name as appname,
(case a.dbsrctype when 1 then 
(select serverIp||':'||port||','||username||'/'||password||'@'||dbname from t_database d where d.id=a.id)  
else 
(select url from t_webservice w where w.id=a.id)  
end) as vmark
from t_dbsrc a 
left join t_appsys b 
on