I convert Date in the mysql query does not work with str_to_date?

I am converting Date in Mysql query. It's saved in varchar in database in this format 10-January-2015. I am converting it to year-month-date 2015-01-10. I have used str_to_date(myfield, '%d-%M-%Y'), and date_format(myfield, '%d-%M-%Y'), but it shows no rows.

The query I'm writing shows no rows yet it works when I give exact date in string.

SELECT * FROM table where str_to_date(date, '%d-%M-%Y') = '20-June-2015';

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use mysql Date_Format

Date_Format(date, '%d-%M-%Y')

use query like taht:-

SELECT * FROM table where Date_Format(date, '%d-%M-%Y') = '20-June-2015';

Or use str_to_date like that :-

SELECT * FROM table where date= str_to_date('20-June-2015', '%d-%M-%Y')