Question

我有这个代码这是我在sqlite上的第一个代码，我从这个教程http://www.youtube.com/watch?v=p8TaTgr4uKM中取得了它我完全按照他在视频中所做的那样但它不起作用 DBclass

package com.catarmy.leader.ahmed.dbtest;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class Databasehelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "student.db";
public static final String TABLE_NAME = "student_table";
public static final String COL_1 = "ID";
public static final String COL_2 = "NAME";
public static final String COL_3 = "SURNAME";
public static final String COL_4 = "MARKS";

public Databasehelper(Context context) {
    super(context, DATABASE_NAME, null, 1);
}
@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(" CREATE TABLE " + TABLE_NAME + "(ID INTEGER PRIMARY KEY 
AUTOINCREMENT , NAME TEXT , SURNAME TEXT , MARK INTEGER )");
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS" + TABLE_NAME);
    onCreate(db);
}
public boolean insertData(String name, String surname, String mark) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();
    contentValues.put(COL_2, name);
    contentValues.put(COL_3, surname);
    contentValues.put(COL_4, mark);
    long result = db.insert(TABLE_NAME, null, contentValues);
    if (result == -1)
        return false;
    else
        return true;
}
}

主要活动类

package com.catarmy.leader.ahmed.dbtest;

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

public class MainActivity extends AppCompatActivity {
Databasehelper studentDB;
EditText name;
EditText surname;
EditText marks;
Button add;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    name=(EditText)findViewById(R.id.Name);
    surname=(EditText)findViewById(R.id.Surename);
    marks=(EditText)findViewById(R.id.Marks) ;
    add=(Button)findViewById(R.id.Add);

    studentDB= new Databasehelper(this);
    add();
   }
 public void add(){
 add.setOnClickListener(
         new View.OnClickListener(){
             @Override
             public void onClick(View v) {
   //the boolean here to see if the data insert success 
    boolean isInserted=
       studentDB.insertData(name.getText().toString(),surname.getText().toSt
 ring(),marks.getText().toString());
                  Toast.makeText(MainActivity.this,"data insert 
 ="+isInserted,Toast.LENGTH_LONG).show();
             }
         }
 );
}
}

我的问题是，当我点击添加按钮时，吐司msg说“数据插入 = false“并且表尚未创建。

Answer 1

我找到了解决方案我刚刚更改了数据库名称 import { Component } from '@angular/core'; import { WizardService} from './wizard.service.ts'; @Component({ ... }) export class Step1Component constructor(private wizardService: WizarService) { } onClick(){ this.wizarService.setStep1(); } } 至 public static final String DATABASE_NAME = "student.db" 谢谢

无法将数据添加到sqlite android

1 个答案: