计算日期范围内每个日期的销售数量，postgresql

I have a table with a row for each sale of a product. These rows include a date. I want to know the number of products sold for each distinct day in a range (user specifies the begin and end dates.) There is a distinct row for each sale, so on days where several products were sold, several rows with this date exist. I want to count the number of these rows, with the same date. How might this be done efficiently in postgresql?I have a table with a row for each sale of a pr