Table: windmills_belgium
Columns: location
name_of_mill
type
built
notes

Question: What are the Notes of the Mill Built in the 19th Century?
SQL: SELECT "notes" FROM windmills_belgium WHERE "built" = '19th century'

Question: What is the Type of Mill at Molen de Stud?
SQL: SELECT "type" FROM windmills_belgium WHERE "name_of_mill" = 'molen de stud'

Question: What is the Name of the Mill Built in 1802?
SQL: SELECT "name_of_mill" FROM windmills_belgium WHERE "built" = '1802'

Question: What is the Location of the Mill Built in the Early 19th Century?
SQL: SELECT "location" FROM windmills_belgium WHERE "built" = 'early 19th century'