智慧职教: 创建视图，保存所有借书逾期者名单。代码如下:create overduelistasselect reader.readerID,reader.name from reader where readerID (select from borrow where rtndate null and eprdate
举一反三
- 智慧职教: 更新borrow表每条借书记录的eprdate(到期日期)。 borrow eprdate=timestampadd(day,(select maxdays from readertype where typeID in (select typeID from reader where reader.readerID=.)),brwdate);
- 以下语句除了查询满足条件的记录，还显示（）表的所有记录。SELECT Reader.*,Borrow.ReaderIDFROM Reader LEFT OUTER JOIN Borrow ON Reader.ReaderID=Borrow.ReaderID A: Reader B: Borrow C: book
- 若想查询student表中name为空值的记录，则正确的SQL语句是（ ）。 A: SELECT * FROM student WHERE name = NULL; B: SELECT * FROM student WHERE name like NULL; C: SELECT * FROM student WHERE name = 'NULL'; D: SELECT * FROM student WHERE name is NULL;
- 下面哪一个语句,显示没有Email地址的教师姓名() A: Select name from teacher where email=NULL; B: Select name from teacher where email C: Select name from teacher where email is NULL; D: Select name from teacher where emailis not NULL;
- 在Oracle中，有一个教师表teacher的结构如下： 下面哪个语句显示没有Email地址的教师的姓名（）。 A: select name from teacher where email=null B: select name from teacher where email<>null C: select name from teacher where email is null D: select name from teacher where email is not null