填充SQLite数据库

从我的开发经验，我总是preFER在/ RES加prepared SQLite数据库文件/原folder.You创建/管理使用Firefox的SQLite的经理插件SQLite数据库，这是一个伟大的工具。这种方法实在是太棒了，因为

From my development experience , I always prefer to add a prepared sqlite database file in the /res/raw folder.You create/manage sqlite database using Sqlite Manager addon of Firefox , it's a great tool. This method is really great because

• 首先，我并不需要写C $ CS一堆$创建/管理数据库。
• 最重要的是，一些应用程序需要从pre-填充数据库中读取。我并不需要关心什么应用程序需要和数据库是否为空或者已经填满。它为所有的目的。我只需要编写的软件运行所需要的sql语句简单一些的方法。

下面是我自己的定制DatabaseHelper类。要使用这个类，你需要遵循一些指示。

Here is my own customised DatabaseHelper class. To use this class you'll need to follow some instructions.

1. 如果SQLite数据库大小为1MB以上，然后将文件分割成块，我preFER 512KB块，并把它们放入/ RES / raw目录。

2. 编辑包名，并在下面的类你的数据库文件名。

1. If sqlite database size is more than 1MB then split the file into chunks , I prefer 512KB chunks and place them into /res/raw directory.

2. Edit the package name and your db file names in the following class.

package your.packagee.name;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.content.res.Resources;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import android.widget.Toast;

public class DataBaseHelper extends SQLiteOpenHelper {

private static final String pkg = "your package name";
private static String DB_PATH = "/data/data/" + pkg + "/databases/";

private static String DB_NAME = "yourDBFile.sqlite";
int[] dbfiles = { R.raw.chunk1 , R.raw.chunk2 ..... };

 private SQLiteDatabase myDataBase;
private final Context myContext;

public DataBaseHelper(Context context) {
    super(context, DB_NAME, null, 1);
    this.myContext = context;
}

public void createDataBase() {

    boolean dbExist = checkDataBase();

    if (dbExist) {
        // do nothing - database already exist
    } else {
        this.getReadableDatabase();
        try {
            CopyDataBase();
        } catch (IOException e) {
            Toast.makeText(myContext, e.getMessage(), Toast.LENGTH_SHORT)
                    .show();
            Log.d("Create DB", e.getMessage());
        }
    }

}

private boolean checkDataBase() {
    SQLiteDatabase checkDB = null;
    try {
        String myPath = DB_PATH + DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.NO_LOCALIZED_COLLATORS);
    } catch (SQLiteException e) {
        Toast.makeText(myContext, e.getMessage(), Toast.LENGTH_SHORT)
                .show();
        Log.d("Check DB", e.getMessage());
    }

    if (checkDB != null) {
        checkDB.close();
    }
    return checkDB != null ? true : false;
}

private void CopyDataBase() throws IOException {
    InputStream databaseInput = null;
    Resources resources = myContext.getResources();
    String outFileName = DB_PATH + DB_NAME;

    OutputStream databaseOutput = new FileOutputStream(outFileName);

    byte[] buffer = new byte[512];
    int length;

    for (int i = 0; i < dbfiles.length; i++) {
        databaseInput = resources.openRawResource(dbfiles[i]);
        while ((length = databaseInput.read(buffer)) > 0) {
            databaseOutput.write(buffer, 0, length);
            databaseOutput.flush();
        }
        databaseInput.close();
    }

    databaseOutput.flush();
    databaseOutput.close();
}

public void openDataBase() throws SQLException {
    String myPath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null,
            SQLiteDatabase.NO_LOCALIZED_COLLATORS);
}

@Override
public synchronized void close() {
    if (myDataBase != null)
        myDataBase.close();
    super.close();
}

@Override
public void onCreate(SQLiteDatabase db) {

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

}

public boolean deleteItem (String ID){

    String query = "delete from item where id='" + ID + "'"  ;
    Log.d("Query : ", query);
    try{
        myDataBase.execSQL(query);
        return true ;
    } catch (Exception e){
        Log.d("Exception", e.toString());
        return false ;
    }
}

public Cursor getSearchFromID(String id) {
    return myDataBase.rawQuery("select * from item where id = \"" + id + "\"", null);
}

public boolean addSave(String type, String data , String time) {

    String query = "insert into item (type, data , timestamp) values ('" + type
    + "', '" + data + "', '" + time + "')"; 
try {
   myDataBase.execSQL(query);
   return true ;
} catch (Exception e) {
   return false ;
}
}
}

下面是写为样本，如何使用它的一些方法。

Here's some methods written as a sample , how to use it.

用法很简单。当你的应用程序启动，这意味着在你的启动活动中使用这种code初始化数据库

Usage is simple. When your application starts , that means in your Launcher activity use this code to initialize your database

DataBaseHelper helper = new DataBaseHelper(this);
helper.createDataBase();
helper.openDataBase();
helper.close();

就用写在DatabaseHelper类中的方法。样本会是这样

Then just use the methods written in DatabaseHelper class. A sample will be like this

 String id = "1";
    DataBaseHelper helper = new DataBaseHelper(this);
    helper.openDataBase();
    Cursor c = helper.getSearchFromID(id);
    if(c.getCount() > 0){
        c.moveToFirst();

      while(!c.isAfterLast()){
        // extract your data from cursor
        c.MoveToNext();
      }
    }

希望这本书能解决你的所有关于Android的SQLite数据库的问题。至少它解决了我。谢谢你。

Hope it will solve your all problems about sqlite database in Android. At least it solved for me. Thank you.