2015 first blog, Oracle time period query, comparison of TO_DATE and TO_CHAR, to_dateto_char

2015 first blog, Oracle time period query, comparison of TO_DATE and TO_CHAR, to_dateto_char
Preface:
During time period query, when TO_DATE is used, including the start date, not the end date;
When TO_CHAR is used, the start date or end date can be included. Effect

1. TO_DATE is used and no end date is found.

2. Use TO_CHAR to query the end date.

3. SQL comparison

-- Includes the start date, excluding the end date SELECT * from1__logwhere (OPERATE_TIME> TO_DATE ('2017-02-03 ', 'yyyy-mm-dd ') AND OPERATE_TIME <TO_DATE ('1970-02-06 ', 'yyyy-mm-dd') ORDER BYOPERATE_TIME DESC; -- including the start date AND end date SELECT * from1__logwhereto_char (OPERATE_TIME, 'yyyy-mm-dd')> = '2017-02-03 'AND TO_CHAR (OPERATE_TIME, 'yyyy-mm-dd') <= '2017-02-06' ORDER BYOPERATE_TIME DESC;