java - 我的表没有在 Sqlite 中创建(Toast for dataNotInserted)....下面的代码 fragment

Question

我的表没有在 Sqlite 中创建(Toast for dataNotInserted)。下面的代码 fragment ...

异常

android.database.sqlite.SQLiteException: no such table: PETROL.DB (code 1): , while compiling: INSERT INTO PETROL.DB(AMOUNT) VALUES (?)

Activity2.java

public class Activity2 extends AppCompatActivity {
    EditText ET1;
    Button B1;
    Button Bview;
    DatabaseHelper myDb;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_2);


        myDb = new DatabaseHelper(this);
        ET1 = findViewById(R.id.editText_amount);
        B1 = findViewById(R.id.button_add);
        Bview = findViewById(R.id.button_view);
        AddData();

    }


    public void AddData() {
        B1.setOnClickListener(new View.OnClickListener() {
            @Override 
            public void onClick(View view) {
                boolean isInserted = myDb.insertData(Integer.parseInt(ET1.getText().toString()));
                if (isInserted == true) {
                    Toast.makeText(Activity2.this, "DataInserted", Toast.LENGTH_LONG).show();
                } else
                    Toast.makeText(Activity2.this, "DataNotInserted", Toast.LENGTH_LONG).show();
            }
        }
        );
    }
}

DatabaseHelper.java

public class DatabaseHelper extends SQLiteOpenHelper {
    public static final String DATABASE_NAME="PETROL.DB";
    public static final String TABLE_NAME="PETROL_TABLE";
    public static final String COL_1="ID";
    public static final String COL_2="AMOUNT";

    public DatabaseHelper(Context context)
    {
        super(context,DATABASE_NAME,null,1);
    }


    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {

        sqLiteDatabase.execSQL( "CREATE TABLE  " + TABLE_NAME + "(" + COL_1 + " INTEGER PRIMARY KEY AUTOINCREMENT," + COL_2 + " INTEGER );");

        Log.d("data","ghgc");
    }

    public boolean insertData(int data)
    {
        SQLiteDatabase sqLiteDatabase=this.getWritableDatabase();
        ContentValues contextValues=new ContentValues();
        contextValues.put("AMOUNT",data);
        Log.d("insertData",Integer.toString(data));
       long result= sqLiteDatabase.insert(DATABASE_NAME,null,contextValues);
       if(result==-1)
           return false;//to check if data is inserted
       else
           return true;
       //sqLiteDatabase.close();

    }
}

未提及 onUpgrade，因为我仍在开发版本 1

Answer 1

您的问题与消息一致，是由于您将数据库名称 PETROL.DB 传递给 insert 方法而不是传递表名称而引起的。根据方法的签名:-

long insert(String table, String nullColumnHack, ContentValues values)

Convenience method for inserting a row into the database. SQLiteDatabase - insert

因此改变:-

    long result= sqLiteDatabase.insert(DATABASE_NAME,null,contextValues);

至:-

    long result= sqLiteDatabase.insert(TABLE_NAME,null,contextValues);