android SQLite的CRUD

activity12.java

package com.wansha;

import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

import com.wansha.db.DatabaseHelper;

public class Activity12 extends Activity {
	private Button createDatabase;
	private Button updateDatabase;
	private Button insert;
	private Button update;
	private Button read;
	private Button delete;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    	this.createDatabase = (Button)this.findViewById(R.id.createDatabase);
    	this.createDatabase.setOnClickListener(new CreateDatabaseListener());
    	
    	this.updateDatabase = (Button)this.findViewById(R.id.updateDatabase);
    	this.updateDatabase.setOnClickListener(new UpdateDatabaseListener());
    	
    	this.insert = (Button)this.findViewById(R.id.insert);
    	this.insert.setOnClickListener(new InsertListener());
    	
    	this.update = (Button)this.findViewById(R.id.update);
    	this.update.setOnClickListener(new UpdateListener());
    	
    	this.read = (Button)this.findViewById(R.id.read);
    	this.read.setOnClickListener(new ReadListener());
    	
    	this.delete = (Button)this.findViewById(R.id.delete);
    	this.delete.setOnClickListener(new DeleteListener());
    	
    }
    class CreateDatabaseListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
    		sqlite.getReadableDatabase();
    	}
    }
    class UpdateDatabaseListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		System.out.println("UpdateDatabaseListener  is invoked !!!");
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp",2);
    		sqlite.getReadableDatabase();
    	}
    }
    class InsertListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
    		SQLiteDatabase database = sqlite.getWritableDatabase();
    		ContentValues values = new ContentValues();
    		values.put("username", "xiaopeng");
    		database.insert("sharp", null, values);
    	}
    }
    class UpdateListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
    		SQLiteDatabase database = sqlite.getWritableDatabase();
    		ContentValues values = new ContentValues();
    		values.put("username", "pengpeng");
    		database.update("sharp", values, "id=?", new String[]{"2"});
    	}
    }
    class ReadListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
    		SQLiteDatabase database = sqlite.getWritableDatabase();
    		Cursor cursor = database.query("sharp", new String[]{"id","username"}, null, null, null, null, null);
    		while(cursor.moveToNext()){
    			String username = cursor.getString(cursor.getColumnIndex("username"));
    			System.out.println("username---->" + username);
    		}
    	}
    }
    class DeleteListener implements OnClickListener{
    	@Override
    	public void onClick(View v) {
    		SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");
    		SQLiteDatabase database = sqlite.getWritableDatabase();
    		database.delete("sharp", "id=?", new String[]{"1"});
    	}
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

	<Button android:id="@+id/createDatabase"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="创建数据库"
	    />
	<Button android:id="@+id/updateDatabase"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="更新数据库"
	    />
	<Button android:id="@+id/insert"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="插入数据"
	    />
	<Button android:id="@+id/update"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="更新数据"
	    />
	<Button android:id="@+id/read"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="读取数据"
	    />
	<Button android:id="@+id/delete"
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="删除数据"
	    />
</LinearLayout>

db.execSQL("create table sharp(id integer primary key autoincrement, username varchar(255))");

创建自增长ID

DatebaseHelper.java

package com.wansha.db;

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

public class DatabaseHelper extends SQLiteOpenHelper{
	private static final int VERSION = 1;
	public DatabaseHelper(Context context, String name, CursorFactory factory,
			int version) {
		super(context, name, factory, version);
	}
	public DatabaseHelper(Context context, String name,int version) {
		this(context, name, null, version);
	}
	public DatabaseHelper(Context context, String name) {
		this(context, name, VERSION);
	}
	@Override
	public void onCreate(SQLiteDatabase db) {
		System.out.println("create table is invoked !!!");
		db.execSQL("create table sharp(id integer primary key autoincrement, username varchar(255))");
	}
	@Override
	public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
		System.out.println("update table is invoked !!!");
	}
	
}