CREATE TABLE table_204_564 (id DECIMAL, "devanagari" TEXT, "iso 15919" TEXT, "unrsgn" TEXT, "iast" TEXT, "comment" TEXT)

what unrsgn is listed previous to the o ?
SELECT "unrsgn" FROM table_204_564 WHERE id = (SELECT id FROM table_204_564 WHERE "unrsgn" = 'o') - 1
SELECT "unrsgn" FROM "table_204_564" WHERE "id" = (SELECT "id" FROM "table_204_564" WHERE "unrsgn" = 'o') - 1