user: Question: What is the sum of the area values for districts having density over 462 and websites of http://krishna.nic.in/?
Columns: ['Code', 'District', 'Headquarters', 'Population (2011)', 'Area (km²)', 'Density (/km²)', 'Official website']
Types: ['text', 'text', 'text', 'real', 'real', 'real', 'text']
Sample row: ['AD', 'Adilabad', 'Adilabad', 2737738.0, 16105.0, 170.0, 'http://adilabad.nic.in/']
SQL:

assistant: SELECT SUM("Area (km²)") FROM "Table" WHERE "Density (/km²)" > 462.0 AND "Official website" = 'http://krishna.nic.in/';