A.SELECT price FROM book WHERE book_name=“數(shù)據(jù)庫*” B.SELECT price FROM book WHERE book_name LIKE“數(shù)據(jù)庫*” C.SELECT price FROM book WHERE book_name=“數(shù)據(jù)庫%” D.SELECT price FROM book WHERE book_name LIKE“數(shù)據(jù)庫%”
A.DROP SCHEMA B.CREATE TABLE C.DROP VIEW D.DROP INDEX
A.由可以區(qū)分該關系模式中的任何元組的單個屬性組成 B.由任意多個屬性組成 C.由一個或多個能區(qū)分該關系模式中任何元組的單個或多個屬性組成 D.由任意單個屬性組成