正确写法2):UPDATE A SET A.mobilephone = b.mobile FROM tb_contact A,tmp_contact b WHERE A.contact_name = b.name
正确写法1):UPDATE tb_contact SET tb_contact.mobilephone = b.mobile FROM tmp_contact b WHERE tb_contact.contact_name = b.name
个人认为正确写法2比较简洁．
可以看出,表名只能declare一次,其他形式写法都会有误,比如:
错误写法1): UPDATE tb_contact A SET A.mobilephone = b.mobile FROM tmp_contact b WHERE A.contact_name = b.name