declare @db1 varchar(25), @db2 varchar(25), @sql1 varchar(5000), @sql2 varchar(5000), @sql3 varchar(5000)
set @db1 = 'db1name'
set @db2 = 'db2name'
set @sql1 = '(select O1.name Tabella, C1.colId, C1.name Campo, T1.name Tipo, C1.length Lunghezza,
C1.xPrec Precisione, C1.xScale Scale, C1.isNullable
from ' + @db1 + '.dbo.syscolumns C1
join ' + @db1 + '.dbo.sysobjects O1 on C1.id = O1.id
join ' + @db1 + '.dbo.systypes T1 on C1.xtype = T1.xusertype) DB1 '
set @sql2 = '(select O1.name Tabella, C1.ColId, C1.name Campo, T1.name Tipo, C1.length Lunghezza,
C1.xPrec Precisione, C1.xScale Scale, C1.isNullable
from ' + @db2 + '.dbo.syscolumns C1
join ' + @db2 + '.dbo.sysobjects O1 on C1.id = O1.id
join ' + @db2 + '.dbo.systypes T1 on C1.xtype = T1.xusertype) DB2 '
set @sql3 = 'select DB1.* , '''
+ @db1
+ ' <--------> '
+ @db2 + ''', DB2.* from '
+ @sql1
+ ' full outer join '
+ @sql2
+ ' on Db1.Tabella = Db2.tabella and Db1.Campo = Db2.Campo
where Db1.Tabella is null or DB2.Tabella is null or Db1.Tipo <> DB2.Tipo
or DB1.Lunghezza <> DB2.Lunghezza or DB1.Precisione <> DB2.Precisione
or DB1.Scale <> DB2.Scale or DB1.isNUllable <> DB2.isNullable
order by case when Db1.Tabella is null then DB2.Tabella else DB1.Tabella end,
case when isnull(DB1.Colid,1000) < isnull(Db2.Colid,1000) then DB1.ColId else DB2.ColId end'
exec (@sql3)