A.Alter table tablename rename to new_name B.Alter table tablename rename new_name C.Rename tablename to newname D.Rename tablename newname
A.主鍵列的數(shù)據(jù)類型不限,但此列必須是唯一并且非空 B.一張數(shù)據(jù)表只能有一個唯一約束 C.唯一性約束所在的列允許空值 D.數(shù)據(jù)表可以包含有多個主鍵約束
A.名稱 B.名稱[] C.名稱[字符] D.名稱[數(shù)字]