A.%NOTFOUND B.%FOUND C.%ROWTYPE D.%ISCLOSE
在Oracle中,有一個教師表teacher的結(jié)構(gòu)如下: IDNUMBER(5),NAMEVARCHAR2(25),EMAILVARCHAR2(50) 下面哪個語句顯示沒有Email地址的教師姓名()
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;
A.select seq.ROWNU Mfrom dual; B.select seq.ROWID from dual; C.select seq.CURRVAL from dual; D.select seq.NEXTVAL from dual;