将日期转换为字符串SQL

Question

I am building report in data warehouse which relay on comparing daily checks and payments for one of the restaurants. I need to be able to filter data on date field however it needs to be compared with string that looks like US date format but is string so

Select a.* from 
xx a, xy b
where 
a.payment_date = b.check_date

Format of a.payment_date is DD-MON-YY(date) and format of b.check_date is MM/DD/YYYY however it is a string. Any pointers to most efficient ways of solving this problem greatly appreciated.

Answer 1

Convert check_date from string to date using TO_DATE() :

SELECT a.*
FROM xx a, xy b
WHERE a.payment_date = TO_DATE(b.check_date, 'mm/dd/yyyy')

Or you can do the other way around, using TO_CHAR() .

Answer 2

将两个String日期都转换为真实日期（ http://www.techonthenet.com/oracle/functions/to_date.php ），以便您可以按日期比较它们。

Answer 3

i think this may work fr you

Select a.* from xx a, xy b where convert(datetime,a.payment_date) = convert(datetime,b.check_date)