У меня ошибка в операторе SQLite ON DELETE CASCADE в моем приложении для викторины - PullRequest
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У меня ошибка в операторе SQLite ON DELETE CASCADE в моем приложении для викторины

0 голосов
/ 01 апреля 2020

Ниже приведен код, в котором произошла ошибка, приложение содержит тысячи строк кода, поэтому я помещаю только оператор с синтаксической ошибкой см. Скобку, вставленную в оператор удаления каскада Заявление SQLite НА УДАЛЕННОМ КАСКАДЕ и как я могу удалить эту ошибку Любая помощь приветствуется. 

   @Override
    public void onCreate(SQLiteDatabase db) {
        this.db = db;

        final String SQL_CREATE_CATEGORIES_TABLE = "CREATE TABLE " +
                ChaptersTable.TABLE_NAME + "( " +
                ChaptersTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                ChaptersTable.COLUMN_NAME + " TEXT " +
                ")";
        final String SQL_CREATE_SUBJECTS_TABLE = "CREATE TABLE " +
                SubjectsTable.TABLE_NAME + "( " +
                SubjectsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                SubjectsTable.COLUMN_NAME + " TEXT " +
                ")";


        final String SQL_CREATE_QUESTIONS_TABLE = "CREATE TABLE " +
                QuestionsTable.TABLE_NAME + " ( " +
                QuestionsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
                QuestionsTable.COLUMN_QUESTION + " TEXT, " +
                QuestionsTable.COLUMN_OPTION1 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION2 + " TEXT, " +
                QuestionsTable.COLUMN_OPTION3 + " TEXT, " +
                QuestionsTable.COLUMN_ANSWER_NR + " INTEGER, " +
                QuestionsTable.COLUMN_DIFFICULTY + " TEXT, " +
                QuestionsTable.COLUMN_SUBJECT_ID+ " INTEGER, " +
                "FOREIGN KEY(" + QuestionsTable.COLUMN_SUBJECT_ID+ ") REFERENCES " +
                SubjectsTable.TABLE_NAME + "(" + SubjectsTable._ID + ")" + "ON DELETE CASCADE" /*(Here im having error)*/
+
                QuestionsTable.COLUMN_CHAPTER_ID + " INTEGER, " +
                "FOREIGN KEY(" + QuestionsTable.COLUMN_CHAPTER_ID + ") REFERENCES " +
                ChaptersTable.TABLE_NAME + "(" + ChaptersTable._ID + ")" + "ON DELETE CASCADE" +
                ")";

        db.execSQL(SQL_CREATE_CATEGORIES_TABLE);
        db.execSQL(SQL_CREATE_QUESTIONS_TABLE);
        db.execSQL(SQL_CREATE_SUBJECTS_TABLE);
        fillCategoriesTable();
        fillQuestionsTable();
        fillSubjectsTable();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + ChaptersTable.TABLE_NAME);
        db.execSQL("DROP TABLE IF EXISTS " + SubjectsTable.TABLE_NAME);
        db.execSQL("DROP TABLE IF EXISTS " + QuestionsTable.TABLE_NAME);
        onCreate(db);
    }

    @Override
    public void onConfigure(SQLiteDatabase db) {
        super.onConfigure(db);
        db.setForeignKeyConstraintsEnabled(true);
    }

1 Ответ

0 голосов
/ 01 апреля 2020

Правильный синтаксис - определить внешние ключи, где вы определяете сам столбец, а не позже: 

final String SQL_CREATE_QUESTIONS_TABLE = "CREATE TABLE " +
        QuestionsTable.TABLE_NAME + " ( " +
        QuestionsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
        QuestionsTable.COLUMN_QUESTION + " TEXT, " +
        QuestionsTable.COLUMN_OPTION1 + " TEXT, " +
        QuestionsTable.COLUMN_OPTION2 + " TEXT, " +
        QuestionsTable.COLUMN_OPTION3 + " TEXT, " +
        QuestionsTable.COLUMN_ANSWER_NR + " INTEGER, " +
        QuestionsTable.COLUMN_DIFFICULTY + " TEXT, " +
        QuestionsTable.COLUMN_SUBJECT_ID+ " INTEGER " + "REFERENCES " +
        SubjectsTable.TABLE_NAME + "(" + SubjectsTable._ID + ") " + "ON DELETE CASCADE," +
        QuestionsTable.COLUMN_CHAPTER_ID + " INTEGER " + "REFERENCES " +
        ChaptersTable.TABLE_NAME + "(" + ChaptersTable._ID + ") " + "ON DELETE CASCADE" +
        ")";

или все внешние ключи в конце оператора: 

final String SQL_CREATE_QUESTIONS_TABLE = "CREATE TABLE " +
        QuestionsTable.TABLE_NAME + " ( " +
        QuestionsTable._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
        QuestionsTable.COLUMN_QUESTION + " TEXT, " +
        QuestionsTable.COLUMN_OPTION1 + " TEXT, " +
        QuestionsTable.COLUMN_OPTION2 + " TEXT, " +
        QuestionsTable.COLUMN_OPTION3 + " TEXT, " +
        QuestionsTable.COLUMN_ANSWER_NR + " INTEGER, " +
        QuestionsTable.COLUMN_DIFFICULTY + " TEXT, " +
        QuestionsTable.COLUMN_SUBJECT_ID+ " INTEGER, " +
        QuestionsTable.COLUMN_CHAPTER_ID + " INTEGER, " +
        "FOREIGN KEY(" + QuestionsTable.COLUMN_SUBJECT_ID+ ") REFERENCES " +
        SubjectsTable.TABLE_NAME + "(" + SubjectsTable._ID + ") " + "ON DELETE CASCADE," +
        "FOREIGN KEY(" + QuestionsTable.COLUMN_CHAPTER_ID + ") REFERENCES " +
        ChaptersTable.TABLE_NAME + "(" + ChaptersTable._ID + ") " + "ON DELETE CASCADE" +//here must come '+' to remove syntax errors 
        ")";
...