Thanks for the hint.So it must be like this

to_date('01-02-2009','mm-dd-yyyy')=to_date('send_date','mm-dd-yyyy')

Best Regards

for Oracle characters between single quote marks are STRINGS
'send_date' -- is a string & not a valid date regardless of transformation.

In fact, firstly I thought it means first two months (January and February) in the year 2009.
Even after correcting, it is only a string. Only you know whether it is January, 2nd or February, 1st (luckily year has 4 digits; there could be other possible dates in play with 2 digit year).

I wonder, whether you and read my first post, as everything is there.

If SEND_DATE has DATE data type, it is a mistake to pass it to TO_DATE function, as it accepts parameter with VARCHAR2 data type.
On the other hand, '01-02-2009' has VARCHAR2 data type; TO_DATE with appropriate format mask converts it to DATE datatype (similarly TO_TIMESTAMP converts it to TIMESTAMP data type). This is your aim, you shall Please, sit down for a while, read the documentation, have a look at some examples (yes, even the documentation contains some) and then start creating some conditions with the rules I posted.

Here what I got from this thread ?

@ send_date has date type in the table

send_date=to_date('01-01-2010','DD-MM-YYYY')

or

trunc(send_date)=to_date('01-01-2010','DD-MM-YYYY')



@ send_date has date timestamp in the table,this could be variations of timestamp,like timestamp(3),timestamp(6)

send_date=timestamp('01-01-2010','DD-MM-YYYY')



@ send_date has varchar type,or string

to_date(send_date,'mm-dd-yyyy')=to_date('01-02-2009','mm-dd-yyyy')

to_timestamp(send_date,'mm-dd-yyyy')=to_timestamp('01-02-2009','mm-dd-yyyy')

that looks correct