Java android SQLite数据库。。没有此类表格：

我又有另一个问题：( 我遇到的错误是，它没有创建名为contacts的表，但我有创建数据库的代码，但它没有创建。如何解决此问题？再次感谢您的回答

package com.mobilebasedsignlanguage;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;

public class alphaconv extends Activity {
ArrayList<Contact> imageArry = new ArrayList<Contact>();
ContactImageAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.alphabetview);

    DataBaseHandler db = new DataBaseHandler(this);
    //get image from drawable..
    Bitmap image = BitmapFactory.decodeResource(getResources(), R.drawable.a);

    //convert bitmap to byte
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    image.compress(Bitmap.CompressFormat.JPEG, 100, stream);
    byte imageInByte[] = stream.toByteArray();
    //Inserting Contacts
    Log.d("Insert: ", "Inserting ..");
    db.addContact(new Contact("A", imageInByte));

    //Read all contacts from db
    List<Contact> contacts = db.getAllContacts();
    for(Contact cn: contacts) {
        String log = "ID: " + cn.getID() + "Name: " + cn.getName() + ", Image: " + cn.getImage();

        Log.d("Result: ", log);
        imageArry.add(cn);
    }

    adapter = new ContactImageAdapter(this, R.layout.screen_list, imageArry);
    ListView dataList = (ListView)findViewById(R.id.list);
    dataList.setAdapter(adapter);

}

}

ContactImageAdapter.java

package com.mobilebasedsignlanguage;

import java.io.ByteArrayInputStream;
import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class ContactImageAdapter extends ArrayAdapter<Contact>{
Context context;
int layoutResourceId;

ArrayList<Contact> data=new ArrayList<Contact>();
public ContactImageAdapter(Context context, int layoutResourceId, ArrayList<Contact> data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    ImageHolder holder = null;

    if(row == null)
    {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new ImageHolder();
        holder.txtTitle = (TextView)row.findViewById(R.id.txtTitle);
        holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
        row.setTag(holder);
    }
    else
    {
        holder = (ImageHolder)row.getTag();
    }

    Contact picture = data.get(position);
    holder.txtTitle.setText(picture._name);

    byte[] outImage = picture._image;
    ByteArrayInputStream imageStream = new ByteArrayInputStream(outImage);
    Bitmap theImage = BitmapFactory.decodeStream(imageStream);
    holder.imgIcon.setImageBitmap(theImage);
    return row;
}

static class ImageHolder
{
    ImageView imgIcon;
    TextView txtTitle;
}


}

---

在onCreate方法中执行日志或toast以查看是否调用了它，如果是，则删除旧表，因为它只调用一次，如果该表已经存在，则不会再次执行

另外，请尝试使用下面的查询，有时create语句中的空格会导致问题

 String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + " ("
        + KEY_ID + " INTEGER PRIMARY KEY, " + KEY_NAME + " TEXT, "
        + KEY_IMAGE + " BLOB" + ");";

---

问题是您没有覆盖

SQLiteOpenHelper

onCreate

方法，因此没有调用它

尝试在

onCreate

和

onUpgrade

方法上放置

override

注释：

@Override
public void onCreate(SQLiteDatabase db) {
     String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
        + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
        + KEY_IMAGE + " BLOB" + ")";
     db.execSQL(CREATE_CONTACTS_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);

     onCreate(db);
}

---

如果您对表架构进行了任何更改，则数据库文件不会自动更新。强制更新的最简单方法是卸载应用程序，以便删除数据库并

onCreate（）

再次被调用。如何执行此操作，先生？我仍在尝试将其运行到emulator@laaltoFor，例如，

adb卸载您的.package.name

@laalto谢谢您，先生。它现在工作正常：）我尝试包含覆盖，但没有找到该表@Giacomoni您可以尝试将数据库版本更改为2（在我的答案中有更改），然后它将重新创建您的数据库。也许它不是您第一次运行它时创建的。

02-18 11:49:25.938: E/SQLiteLog(6044): (1) no such table: contacts
02-18 11:49:26.078: E/SQLiteDatabase(6044): Error inserting image=[B@40e29b40 name=A
02-18 11:49:26.078: E/SQLiteDatabase(6044): android.database.sqlite.SQLiteException: no such table: contacts (code 1): , while compiling: INSERT INTO contacts(image,name) VALUES (?,?)

 String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + " ("
        + KEY_ID + " INTEGER PRIMARY KEY, " + KEY_NAME + " TEXT, "
        + KEY_IMAGE + " BLOB" + ");";

@Override
public void onCreate(SQLiteDatabase db) {
     String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
        + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
        + KEY_IMAGE + " BLOB" + ")";
     db.execSQL(CREATE_CONTACTS_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
     db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);

     onCreate(db);
}