如何使用 UPDATE...SELECT 做大量更新？

MS SQL 語法： update a set a2=b.b2, a3=b.b3, ... 2 from b 3 where a.a1=b.b1 (MS SQL Server)語句：update b set ClientName = a.name from a,b where a.id = b.id (Oralce)語句：update b set (ClientName) = (SELECT name FROM a WHERE b.id = a.id)