按下按钮时，SQLlite会导致崩溃

Question

我有一个应用程序，我尝试在使用SQLlite创建的表中添加用户信息。问题是当我按下添加按钮时应用程序崩溃。下面我包括所有的代码和logcat。

MainActivity.java

package com.example.asus.sqlliteproject;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    DataBaseHelper myDB;
    EditText Name,LastName,Grades;
    Button AddData;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        myDB = new DataBaseHelper(this);
        Name = (EditText)findViewById(R.id.name);
        LastName = (EditText)findViewById(R.id.lastName);
        Grades = (EditText)findViewById(R.id.Grades);
        AddData = (Button)findViewById(R.id.addDataButton);
        addData();
    }
    public void addData () {
        AddData.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                boolean inserted = myDB.insertData(Name.getText().toString(),
                        LastName.getText().toString(),
                        Grades.getText().toString());
                if (inserted){
                    Toast.makeText(MainActivity.this,"Text Inserted!", Toast.LENGTH_SHORT).show();
                } else
                    Toast.makeText(MainActivity.this,"Unsuccessful!", Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

DataBaseHelper.java

package com.example.asus.sqlliteproject;

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/**
 * Created by Asus on 29.4.2016.
 */
public class DataBaseHelper extends SQLiteOpenHelper {

    public static final String DataBaseName = "student.db";
    public static final String DataTableName = "studentTable.db";
    public static final String ColID = "ID";
    public static final String ColName = "Name";
    public static final String ColLastName = "LastName";
    public static final String ColGrades = "Grade";

    public DataBaseHelper(Context context) {
        super(context, DataBaseName, null, 1);
        //SQLiteDatabase db = this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table" + DataTableName + "(ID INTEGER PRIMARY KEY AUTOINCREMENT)," +
                "Name TEXT, LastName TEXT, Grade INTEGER");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("Drop table if exists" + DataTableName);
        onCreate(db);
    }
    public boolean insertData (String name, String LastName, String Grades) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(ColName,name);
        contentValues.put(ColLastName,LastName);
        contentValues.put(ColGrades,Grades);
        long result = db.insert(DataTableName, null, contentValues);
        if (result == -1) {
            return false;
        }else
            return true;
    }
}

logcat错误（分为两个imgs）和activity_main视图

Answer 1

你错过了空格“创建表格”应该“创建表格”

不要忘记白色空间。

试试这个：

public class DataBaseHelper extends SQLiteOpenHelper {

    public static final String DataBaseName = "student.db";
    public static final String DataTableName = "studentTable";
    public static final String ColID = "ID";
    public static final String ColName = "Name";
    public static final String ColLastName = "LastName";
    public static final String ColGrades = "Grade";

    public DataBaseHelper(Context context) {
        super(context, DataBaseName, null, 1);
        //SQLiteDatabase db = this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table " + DataTableName + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " +
                "Name TEXT, LastName TEXT, Grade INTEGER);");

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("Drop table if exists" + DataTableName);
        onCreate(db);
    }
    public boolean insertData (String name, String LastName, String Grades) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(ColName,name);
        contentValues.put(ColLastName,LastName);
        contentValues.put(ColGrades,Grades);
        long result = db.insert(DataTableName, null, contentValues);
        if (result == -1) {
            return false;
        }else
            return true;
    }

}

Answer 2

一旦我得到类似的错误。我只是简单地替换了ID＆＃39; ID＆＃39; by＆＃39; _id＆＃39;它就像一个魅力。