iOS 数据库第二。三张表不能插入数据，第一张可以，为什么

Question

• (id)init
  {
  self = [super init];
  if (self) {

  NSArray * arr = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  _filePath = [arr objectAtIndex:0];
  
  _filePath = [_filePath stringByAppendingPathComponent:@"Test.db"];
  
  NSLog(@"filePath is %@",_filePath);
  _dataBase = [FMDatabase databaseWithPath:_filePath];
  
  if (![_dataBase open]) {
      NSLog(@"can not open dataBase!");
      return nil;
  }
  NSArray *array=[NSArray arrayWithObjects:
                  @"CREATE TABLE if not exists student (Num integer PRIMARY KEY AUTOINCREMENT,studentNumber text,studentName text,studentAddress text)",
                  @"CREATE TABLE if not exists course (b integer PRIMARY KEY AUTOINCREMENT,courseNumber text,courseName text,courseTeacher text)",
                  @"CREATE TABLE if not exists score (a integer PRIMARY KEY AUTOINCREMENT,studentNumber text,courseName text,score text)", nil];
  
  for (NSString * sql in array) {
      [_dataBase executeUpdate:sql];
  }
  

  }
  return self;
  }

• (BOOL)insertDataToDataBase:(id)model andKey:(NSInteger)key;
  {

  if ([model isKindOfClass:[StedentModel class]]) {

  StedentModel *sModel = (StedentModel *)model;
  
  return [_dataBase executeUpdate:@"INSERT INTO student (Num,studentNumber,studentName,studentAddress) VALUES (?,?,?,?)",[NSNumber numberWithInt:key],sModel.studentNumber,sModel.studentName,sModel.studentAddress];
  

  }
  if ([model isKindOfClass:[CourseModel class]]){

  CourseModel *cModel = (CourseModel *)model;
  return [_dataBase executeUpdate:@"INSERT INTO course (b,courseNumber,courseName,courseTeacher,) VALUES (?,?,?,?)",[NSNumber numberWithInt:key],cModel.courseNumber,cModel.courseName,cModel.courseTeacher];
  

  }
  if ([model isKindOfClass:[ScoreModel class]]){

  ScoreModel *sModel = (ScoreModel *)model;
  return [_dataBase executeUpdate:@"INSERT INTO score (a,studentNumber,courseName,score,) VALUES (?,?,?,?)",[NSNumber numberWithInt:key],sModel.studentNumber,sModel.courseName,sModel.score];
  

  }else{
  return YES;
  }

}
Nicholas 09:59:47

• (IBAction)saveButtonPressed:(UIButton *)sender {

  StedentModel *stuModel = [[StedentModel alloc]init];
  CourseModel *couModel = [[CourseModel alloc]init];
  ScoreModel *scoModel = [[ScoreModel alloc]init];

  stuModel.studentNumber = _sNumberTextField.text;
  stuModel.studentName = _sNameTextField.text;
  stuModel.studentAddress = _sAddressTextField.text;

  couModel.courseNumber = _cNumberTextField.text;
  couModel.courseName = _cName.text;
  couModel.courseTeacher = _cTeacherTextField.text;

  scoModel.studentNumber = _scoreNumberTextField.text;
  scoModel.courseName = _scoreNameTextField.text;
  scoModel.score = _scoreTextField.text;

  DateBaseSimple *dateBase = [DateBaseSimple sharedDataBase];
  [dateBase insertDataToDataBase:couModel andKey:4];
  [dateBase insertDataToDataBase:scoModel andKey:4];
  [dateBase insertDataToDataBase:stuModel andKey:4];

}