ORACLE 時間類型的處理

— 創建日期時間測試表----------------
create table testdatetime(
ID integer not null primary KEY,
createdate CHAR(10) NULL,
startdate DATE NULL,
enddate DATE NULL,
buydate CHAR(10) NULL,
usedate varchar2(20) NULL
) ;
------------------------ 日期時間範圍查詢 ------------------------------------
–字段爲：字符串類型（char），長度爲:10
（1）SELECT * FROM testdatetime t WHERE 1=1 AND t.createdate = ‘2011-07-01’;
SELECT * FROM testdatetime t WHERE 1=1 AND t.createdate >= ‘2011-06-01’ AND t.createdate <= ‘2011-07-05’;

（2）SELECT * FROM testdatetime t WHERE 1=1 AND to_date(t.createdate,‘yyyy-MM-dd’) between to_date(‘2011-06-01’,‘yyyy-MM-dd’) and to_date(‘20110705’,‘yyyymmdd’) ;

（3）–字段爲：日期時間類型（date）
SELECT * FROM testdatetime t WHERE 1=1 AND t.startdate >= to_date(‘2011-07-01’,‘yyyy-MM-dd’)
AND t.startdate <= to_date(‘2011-07-02’,‘yyyy-MM-dd’);

（4）SELECT * FROM testdatetime t WHERE 1=1 AND to_char(t.startdate,‘yyyy-MM-dd’) between ‘2011-07-01’ AND ‘2011-07-02’;