“字符型”转换成“日期型”的实例脚本

15:13:46 SQL> 15:13:46 SQL> CREATE TABLE ycz_test_12 (row_id varchar2(100),3 start_dt varchar2(100),4 end_dt varchar2(100));Table createdExecuted in 0.02 seconds15:13:47 SQL> CREATE TABLE ycz_test_22 (row_id varchar2(100),3 start_dt date,4 end_dt date);Table createdExecuted in 0.03 seconds15:13:47 SQL> insert into ycz_test_12 values('1','','');1 row insertedExecuted in 0.01 seconds15:13:47 SQL> commit;Commit completeExecuted in 0.01 seconds15:13:47 SQL> insert into ycz_test_22 values3 ('1',to_date('2007-1-1', 'yyyy-mm-dd'), to_date('2008-2-1', 'yyyy-mm-dd'));1 row insertedExecuted in 0.01 seconds15:13:47 SQL> commit;Commit completeExecuted in 0.01 seconds15:13:47 SQL> update ycz_test_1 a2 set (a.start_dt,a.end_dt)=3 (select b.start_dt,b.end_dt4 from ycz_test_2 b5 where a.row_id = b.row_id);1 row updatedExecuted in 0 seconds15:13:47 SQL> commit;Commit completeExecuted in 0.01 seconds15:13:54 SQL> select * from ycz_test_1;ROW_ID START_DT END_DT------------------------1 01-JUL-07 01-AUG-08Executed in 0.03 seconds15:14:02 SQL> 15:18:07 SQL> 15:18:08 SQL> update ycz_test_1 a2 set (a.start_dt,a.end_dt)=3 (select to_char(b.start_dt,'yyyy-mm-dd'),to_char(b.end_dt,'yyyy-mm-dd')4 from ycz_test_2 b5 where a.row_id = b.row_id);1 row updatedExecuted in 0.01 seconds15:18:08 SQL> select * from ycz_test_1;ROW_ID START_DT END_DT-------------------------------------- ------------------------------------- -------------------------------------1 2007-01-01 2008-02-01Executed in 0.03 seconds