rails create new model ans save instance id nil code example

Example: how to define a save method in ruby for sql databases

def save
    sql = <<-SQL
      INSERT INTO songs (name, album) 
      VALUES (?, ?)
    SQL
 
    DB[:conn].execute(sql, self.name, self.album)
 
    @id = DB[:conn].execute("SELECT last_insert_rowid() FROM songs")[0][0]
 
  end