How many chapters does the character Demetrius show in the story?
character Demetrius refers to CharName = 'Demetrius'
SELECT COUNT(DISTINCT T2.chapter_id) FROM characters AS T1 INNER JOIN paragraphs AS T2 ON T1.id = T2.character_id WHERE T1.CharName = 'Demetrius'
database name:db_id shakespeare
chapters table chapters Cols: id dtype integer, Act dtype integer, Scene dtype integer, Description dtype text, work id dtype integer, 
characters table characters Cols: id dtype integer, char name dtype text, abbreviation dtype text, Description dtype text, 
paragraphs table paragraphs Cols: id dtype integer, paragraph number dtype integer, Plain Text dtype text, character id dtype integer, chapter id dtype integer, 
works table works Cols: id dtype integer, Title dtype text, Long Title dtype text, character id dtype integer, genre type dtype text, 
