| SELECT CEIL(N) FROM DUAL;
112. 返回小於等於N的最小整數值
SELECT FLOOR(N) FROM DUAL;
113. 返回當前月的最後一天
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. 如何找資料庫表的主鍵欄位的名稱
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, ...)
日期的各部分的常用的的寫法
119>.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;
121>.取時間點的日的寫法:
SELECT TO_CHAR(SYSDATE,''''DD'''') FROM DUAL;
122>.取時間點的時的寫法:
SELECT TO_CHAR(SYSDATE,''''HH24'''') FROM DUAL;
123>.取時間點的分的寫法:
SELECT TO_CHAR(SYSDATE,''''MI'''') FROM DUAL;
124>.取時間點的秒的寫法:
SELECT TO_CHAR(SYSDATE,''''SS'''') FROM DUAL;
125>.取時間點的日期的寫法:
SELECT TRUNC(SYSDATE) FROM DUAL;
126>.取時間點的時間的寫法:
SELECT TO_CHAR(SYSDATE,''''HH24:MI:SS'''') FROM DUAL;
127>.日期,時間形態變為字元形態
SELECT TO_CHAR(SYSDATE) FROM DUAL;
128>.將字串轉換成日期或時間形態:
SELECT TO_DATE(''''2003/08/01'''') FROM DUAL;
129>.返回參數的星期幾的寫法 上一页 [1] [2] [3] [4] [5] [6] [7] 下一页 |