class StudentDB: def openDB(self): self.con=sqlite3.connect("students.db") self.cursor=self.con.cursor() def closeDB(self): self.con.commit() self.con.close() def initTable(self): res={} try: self.cursor.execute("create table students (No varchar(16) primary key,Name varchar(16), Sex varchar(8), Age int)") res["msg"]="OK" except Exception as err: res["msg"]=str(err) return res def insertRow(self,No,Name,Sex,Age): res={} try: ___________________________________________ res["msg"]="OK" except Exception as err: res["msg"]=str(err) return res 程序插入一条学生记录,缺失的语句是