to_char與to_date的區別

select * from csend where credttm > to_date('2018-06-11','yyyy-mm-dd');

select * from csend where to_char(credttm,'yyyy-mm-dd')>'2018-06-25'

 

結論：to char 是把日期或數字轉換爲字符串
to date 是把字符串轉換爲數據庫中得日期類型