一 在查詢中使用字元函式

1. SQL>select*from users;
2. ID NAME CARDID DEPTNO REGDATE AGE
3. -------------------------------------------------------------------------
4. 1 abc 123456199205050105-5月-1718
5. SQL>select substr
   (cardid ,7,8)from users;
6. SUBSTR(CARDID,7,
7. ----------------
8. 19920505

1. SQL>select replace(deptno ,'01','資訊科技')from users;
2. REPLACE(DEPTNO,'01','資訊科技')
3. --------------------------------------------------------------------------------
4. 資訊科技

1. SQL
   >select mod(age,10)from users;
2. MOD(AGE,10)
3. -----------
4. 8

1. SQL>select extract(year from regdate)from users;
2. EXTRACT(YEARFROMREGDATE)
3. ------------------------
4. 2017
5. SQL>select*from users where extract(month from regdate)=5;
6. ID NAME CARDID DEPTNO REGDATE AGE
7. -------------------------------------------------------------------------
8. 1 abc 123456199205050105-5月-1718