Question

我是数据库的新手。目前我已经创建了一个应用程序，我想将它链接到SQLite数据库。在youtube上关注教程之后，我尝试添加一个简单的行来测试我的数据库。我收到错误E/SQLiteLog: (1) no such table: SCORES E/SQLiteDatabase: Error inserting DScore=0 LScore=0 Name=Aris 这是我现在的代码：

     public class DB_Controller  {
    private DB_Scores helper;

    public DB_Controller(Context context) {
        helper = new DB_Scores(context);
    }

    public long insertRow(String name){
        SQLiteDatabase db=helper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(DB_Scores.NAME, name);
        values.put(DB_Scores.DSCORE, 0);
        values.put(DB_Scores.LSCORE, 0);
        long id = db.insert(DB_Scores.TABLE_NAME,null, values);
        return id;
    }


    static class DB_Scores extends SQLiteOpenHelper {
        private static final String DATABASE_NAME = "scores.db";
        private static final String TABLE_NAME = "SCORES";
        private static final int DATABASE_VERSION = 1;
        private static final String UID = "_id";
        private static final String NAME = "Name";
        private static final String LSCORE = "LScore";
        private static final String DSCORE = "DScore";
        private static final String CREATE_TABLE="CREATE TABLE "+TABLE_NAME+" ("+UID+" INTEGER PRIMARY KEY " +
                "AUTOINCREMENT, "+NAME+" TEXT UNIQUE, "
                +LSCORE+" INTEGER, "+DSCORE+" INTEGER);";
        private Context context;//?

        public DB_Scores(Context context ) {

            super(context, DATABASE_NAME, null, DATABASE_VERSION);
            this.context = context;
            Toast.makeText(context, "Constructor was called", Toast.LENGTH_LONG).show();
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            try {
                db.execSQL(CREATE_TABLE);
                Toast.makeText(context, "onCreate was called", Toast.LENGTH_LONG).show();
            } catch (SQLException e) {
                Toast.makeText(context, ""+e, Toast.LENGTH_LONG).show();
            }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            try{
                db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
                Toast.makeText(context, "onUpgrade called", Toast.LENGTH_LONG).show();
                onCreate(db);
            }catch(SQLException e){
                Toast.makeText(context, ""+e, Toast.LENGTH_LONG).show();
            }
        }
    }
}

我创建DB_Controller对象的活动 public class Scores_Activity extends AppCompatActivity {

private DB_Controller dbController;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.scores_activity);      

    dbController = new DB_Controller(this);
    addRow();

}

public void addRow() {
    long id=dbController.insertRow("Aris");
    if (id < 0) {
        Toast.makeText(this, "Unsuccessful", Toast.LENGTH_SHORT).show();
    } else {
        Toast.makeText(this, "Success", Toast.LENGTH_SHORT).show();
    }
}

它标记为错误来源的行是long id=dbController.insertRow("Aris");，
long id = db.insert(DB_Scores.TABLE_NAME,null, values);和addRow(); 我的猜测是我在创建数据库时出现了逻辑错误。感谢您的时间

Answer 1

更改create table命令，如下所示（不需要在查询末尾加分号）

 private static final String CREATE_TABLE="CREATE TABLE "+TABLE_NAME+" ("+UID+" INTEGER PRIMARY KEY " +
            "AUTOINCREMENT, "+NAME+" TEXT UNIQUE, "
            +LSCORE+" INTEGER, "+DSCORE+" INTEGER )";

试图在android NoSuchTable的sqlite数据库中插入一行

1 个答案: