创建数据库

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<Button
android:id="@+id/create_datebase"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="64dp"
android:text="Create Datebase" />

<Button
android:id="@+id/Add_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/create_datebase"
android:layout_centerHorizontal="true"
android:layout_marginTop="51dp"
android:text="Add" />

<Button
android:id="@+id/Delete_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/Add_date"
android:layout_below="@+id/Add_date"
android:layout_marginTop="16dp"
android:text="Delete" />

<Button
android:id="@+id/Update_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignRight="@+id/Delete_date"
android:layout_below="@+id/Delete_date"
android:layout_marginTop="29dp"
android:text="Update" />

<Button
android:id="@+id/Retrieve_date"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignRight="@+id/Update_date"
android:layout_marginBottom="18dp"
android:text="Retrieve" />

</RelativeLayout>

package com.example.mydatabase;

import com.example.mydatabaseHelper.MyDatabaseHelper;

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

public class MainActivity extends Activity {

private MyDatabaseHelper dbHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dbHelper=new MyDatabaseHelper(this,"BookStore.db",null,2);
Button createDatebase=(Button) findViewById(R.id.create_datebase);
createDatebase.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
dbHelper.getWritableDatabase();
}
});
Button addDatebase=(Button) findViewById(R.id.Add_date);
createDatebase.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
ContentValues values=new ContentValues();
//开始组装第一条数据
values.put("name","The Da Vinci Code");
values.put("author","Dan Brown");
values.put("pages",454);
values.put("price",16.96);
db.insert("Book",null,values);
//插入第一条数据
values.clear();
//开始组装第二条数据
values.put("name","The Da Vinci Symbol");
values.put("author","Dan Brown");
values.put("pages",510);
values.put("price",16.96);
db.insert("Book",null,values);
//插入第二条数据
}
});
Button updateDatebase=(Button) findViewById(R.id.Update_date);
createDatebase.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
// TODO Auto-generated method stub
SQLiteDatabase db=dbHelper.getWritableDatabase();
ContentValues values=new ContentValues();
values.put("price",10.96);
db.update("Book", values,"name=?",new String[]{"The Da Vinic Code"});
}
});
}

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

}

package com.example.mydatabaseHelper;

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

public class MyDatabaseHelper extends SQLiteOpenHelper{

public static final String CREATE_
4000
BOOK ="create table Book(" +
"id integer primary key autoincrement," +
"author text," +
"price real," +
"pages integer," +
"name text)";
public static final String CREATE_CATEGORY="create table Category(" +
"id integer primary key autoincrement," +
"category_name text," +
"category_code integer)";

private Context mContext;

public MyDatabaseHelper(Context context, String name,
CursorFactory factory, int version) {
super(context, name, factory, version);
// TODO Auto-generated constructor stub
mContext=context;
}

@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
db.execSQL(CREATE_BOOK);
db.execSQL(CREATE_CATEGORY);
Toast.makeText(mContext, "Create successded",Toast.LENGTH_SHORT).show();
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("drop table if exists Book");
db.execSQL("drop table if exists Category");
onCreate(db);
}

}