input: Write a function to select all rows from a table where the 'status' is 'approved'.
  def select_approved_rows():
     sql = "SELECT * FROM table WHERE status = 'approved'"
     cur.execute(sql)
     return cur.fetchall()
  assert select_approved_rows() == [(1, 'approved', 'data1'), (2, 'approved', 'data2')]
  assert select_approved_rows() == [(3, 'not approved', 'data3')]
  assert select_approved_rows() == []
output: def select_approved_rows():
     sql = "SELECT * FROM table WHERE status = 'approved'"
     cur.execute(sql)
     return cur.fetchall()