SQL查询将2019/05/21 00:00:00格式转换为19-JUN-19（即DD-MON-YY）

Question

I have a date format "2019/05/21 00:00:00" and I need to convert this into "21-JUN-19" using SQL. How can I convert this?

Answer 1

Assuming that the source value is a string, then

• first convert it to a date (using to_date , with appropriate format mask)
• then convert it to a string (using to_char , again with appropriate format mask)

By the way, why are you converting 2019/ 05 /21 into jun ? It can be done, no problem ( ADD_MONTHS does that), just wondering whether you did it intentionally or by mistake.

SQL> select to_char(to_date('2019/05/21 00:00:00', 'yyyy/mm/dd hh24:mi:ss'), 'dd-mon-yy') result from dual;

RESULT
---------
21-may-19

SQL>

Answer 2

You can use substr() and to_date() :

select to_date(substr('2019/05/21 00:00:00', 1, 10), 'YYYY/MM/DD')
from dual;