111. 返回大于等于n的最小整數值? select ceil(n) from dual; 112. 返回小于等于n的最小整數值? select floor(n) from dual; 113. 返回當前月的最后一天? select last_day(sysdate) from dual; 114. 如何不同用戶間數據導入? imp system/manager file=aa.dmp fromuser=user_old touser=user_new rows=y indexes=y ;
115. 如何找數據庫表的主鍵字段的名稱? sql>select * from user_constraints where constraint_type='p' and table_name='table_name'; 116. 兩個結果集互加的函數? sql>select * from bsempms_old intersect select * from bsempms_new; sql>select * from bsempms_old union select * from bsempms_new; sql>select * from bsempms_old union all select * from bsempms_new; 117. 兩個結果集互減的函數? sql>select * from bsempms_old minus select * from bsempms_new; 118. 如何配置sequence? 建sequence seq_custid create sequence seq_custid start 1 incrememt by 1; 建表時: create table cust { cust_id smallint not null, ...} insert 時: insert into table cust values( seq_cust.nextval, ...) 119>.日期的各部分的常用的的寫法 取時間點的年份的寫法:select to_char(sysdate,'yyyy') from dual; 120>.取時間點的月份的寫法:select to_char(sysdate,'mm') from dual;
