Question

我构建了以下数据库：

   private static final String CREATE_TABLE_TEST=
        " create table " + TABLE_TEST +
        " (test_id integer primary key autoincrement," +
        COL_GRADE +" text not null," +
        DATE+" text not null);";



private static final String CREATE_TABLE_QUESTION=
        " create table " + TABLE_ANSWER +
        " (question_id integer primary key autoincrement," +
        COL_ANSWER_1+ " text not null,"+ 
        COL_ANSWER_2+" text not null," +
        COL_ANSWER_3+" text not null," +
        COL_ANSWER_4+" text not null," +
        COL_ANSWER_5+ " text not null,"+ 
        COL_ANSWER_6+" text not null," +
        COL_RIGHT_ANSWER+" integer," +
        COL_WRONG_ANSWER+" integer, " +
        COL_TEST_ID+" INTEGER, " + 
        "FOREIGN KEY(" + COL_TEST_ID + ") REFERENCES " + TABLE_TEST+"(test_id));";

到目前为止，错误仍然存在：

> 11-29 18:01:20.955: E/Database(853): Error inserting right_answer=6 wrong_answer=0 answer_5=fadsfas answer_6=gadsfdasasdfa
answer_3 = fasdfasf test_id = 1 answer_4 = fasdfsa answer_1 = fasdfasd ANSWER_2 = fasdfas
11-29 18:01:20.955: E/Database(853): android.database.sqlite.SQLiteException: table answer has no column
命名 test_id :,编译时：INSERT INTO回答（right_answer， wrong_answer，answer_5，answer_6，answer_3， test_id ，answer_4， answer_1，answer_2）VALUES（？，？，？，？，？，？，？，？，？）;

@Override
public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub
        Log.d("database", CREATE_TABLE_TEST); //I never see this statement in catlog
        Log.d("database", CREATE_TABLE_QUESTION); //nor this
        db.execSQL(CREATE_TABLE_QUESTION);
        db.execSQL(CREATE_TABLE_TEST);
    }

@Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // TODO Auto-generated method stub
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_TEST);
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_ANSWER);
        onCreate(db);
    }

我把它放在oncreate ..：

 dbClass=new database(this);        
    try
    {
        Log.w("inside ",  " database opened");///This gets printed
        dbLite=dbClass.getWritableDatabase();
        Log.w("after ",  " database opened");///This get printed
    }
    catch(Exception c)
    {
        Log.v("Open database exception caught", c.getMessage());
        dbLite=dbClass.getReadableDatabase();
    }

onCreate中没有任何东西被打印出来..

好像onCreate永远不会被称为

Answer 1

您的外键未正确

http://www.sqlite.org/foreignkeys.html

了解更多信息

private static final String CREATE_TABLE_QUESTION=
" create table " + TABLE_ANSWER +
" (question_id integer primary key autoincrement," +
COL_ANSWER_1+ " text not null,"+ 
COL_ANSWER_2+" text not null," +
COL_ANSWER_3+" text not null," +
COL_ANSWER_4+" text not null," +
COL_ANSWER_5+ " text not null,"+ 
COL_ANSWER_6+" text not null," +
COL_RIGHT_ANSWER+" integer," +
COL_WRONG_ANSWER+" integer, " +
COL_TEST_ID+" INTEGER, " + 
"FOREIGN KEY(" + COL_TEST_ID + ") REFERENCES " + TABLE_TEST+"(test_id))";

应该做的伎俩

更进一步，您的onCreate方法仅在创建数据库时执行，而不是在升级时执行你应该覆盖onUpgrade以执行更新（或在新设备/模拟器上测试）

http://developer.android.com/reference/android/database/sqlite/SQLiteOpenHelper.html#onUpgrade(android.database.sqlite.SQLiteDatabase,%20int,%20int）

如果扩展sqliteOpenHelper，则需要使用newVersionId调用super-constuctor来触发onUpgrade

public YourDatabase(Context context) {
    super(context, DatabaseName, null, DATABASE_VERSION);
}

提示：从手机/模拟器中完全卸载应用程序并重新安装（然后将删除数据库，如果不是问题出现在其他地方，则会立即创建数据库）

Answer 2

盲目猜测：;之后你需要INTEGER REFERENCES test )吗？

Answer 3

对我跳出的第一件事是在列名之后和create table指令中的列类型之前缺少空格...

COL_GRADE +“text not null，”+ DATE +“text not null）;”;

您确定该表是否已正确创建？

Answer 4

您可以尝试清除应用程序数据吗？有时数据库会在您拥有所有列之前创建，如果您的onUpgrade方法未正确实现，则在您清除数据之前，该列永远不会被添加。

Sqlite异常：找不到列

4 个答案: