A.WHRER B.HAVING C.ORDERBY D.無(wú)法限定分組函數(shù)的返回值
A.%NOTFOUND B.%FOUND C.%ROWTYPE D.%ISCLOSE
在Oracle中,有一個(gè)教師表teacher的結(jié)構(gòu)如下: IDNUMBER(5),NAMEVARCHAR2(25),EMAILVARCHAR2(50) 下面哪個(gè)語(yǔ)句顯示沒(méi)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;