CREATE TABLE table_15797 ("Character" TEXT, "Portrayed by" TEXT, "Main cast seasons" TEXT, "Recurring cast seasons" TEXT, "# of episodes" FLOAT)

Which main cast seasons were portrayed by Joe Jonas?
SELECT "Main cast seasons" FROM table_15797 WHERE "Portrayed by" = 'joe jonas'
SELECT "Main cast seasons" FROM "table_15797" WHERE "Portrayed by" = 'joe jonas'