What is the SQL command to list the number of product sales (number of rows) and total sales by month and product category, with subtotals by month and product category and a grand total for all sales

Part d: float check string has a method s.isdigit() that returns true if string s contains only digits and false otherwise, i.e. s is a string that represents an integer. write a function named float_check that takes one parameter that is a string and returns true if the string represents a float and false otherwise. for the purpose of this function we define a float to be a string of digits that has at most one decimal point. note that under this definition an integer argument will return true. remember “edge cases” such as “45.” or “.45”; both should return true. for example: float_check('1234') returns true float_check('123.45') returns true float_check('123.45.67') returns false float_check('34e46') returns false float_check('.45') returns true float_check('45.') returns true float_check('45..') returns false