Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_19 (area__km²_ INTEGER, density___km²_ VARCHAR, official_website VARCHAR)
### Question:
What is the sum of the area values for districts having density over 462 and websites of http://krishna.nic.in/?
### Answer:
SELECT SUM(area__km²_) FROM table_name_19 WHERE density___km²_ > 462 AND official_website = "http://krishna.nic.in/"