A.CREATE VIEW sales_view AS（SELECT companyname，city，orderid，orderdate，total FROM customers，orders WHERE custid=custid}WITHREAD ONLY
B.CREATE VIEW sales_view（SELECT c.companyname，c.city，o.orderid，o.orderdate，o.tota lFROM customersc，orderso WHERE c.custid=o.custid}WITHREAD ONLY
C.CREATE VIEW sales_view AS（SELECT c.companyname，c.city，o.orderid，o.orderdate，o.total FROM customersc，orderso WHERE c.custid=o.custid}
D.CREATE VIEW sales_view AS（SELECT c.companyname，c.city，o.orderid，o.orderdate，o.total FROM customersc，orderso WHERE c.custid=o.custid）WITHREAD ONLY

A.該視圖允許用戶根據(jù)數(shù)據(jù)字典檢查它
B.禁止更改該視圖定義中子查詢未返回的行
C.禁止沒有經(jīng)過管理員CHECK驗證的DML操作
D.允許從其它表中刪除，包括子查詢中未列出的表