更新时间:2018-11-22 16:07作者:李天扬老师
7) you would like to display the system date in the format“20051110 14:44:17”。which select statement should you use?______。
a. select to_date(sydate,’yearmmdd hh:mm:ss’)from dual;
b. select to_char(sydate,’yearmonthday hh:mi:ss’)from dual;
c. select to_date(sydate,’yyyymmdd hh24:mi:ss’)from dual;
d. select to_char(sydate,’yyyymmdd hh24:mi:ss’)from dual;
e. select to_char(sydate,’yy-mm-dd hh24:mi:ss’)from dual;
8)which select statement will the result ‘ello world’from the string‘hello world’?______.
a. select substr(‘hello world’,1)from dual;
b. select substr(trim(‘hello world’,1,1))from dual;
c. select lower(substr(‘hello world’,1))from dual;
d. select lower(trim(‘h’from‘hello world’))from dual;
9)which are dml statements(choose all that apply)______.