Android入门之SQLiteDatabase联习

上一篇文章SQLite就那么一回事http://blog.csdn.net/imlanbin/article/details/17102717

main.xml 

<?xml version="1.0" encoding="utf-8"?><LinearLayout 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:orientation="vertical" >    <EditText        android:id="@+id/et_name"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:gravity="center_horizontal"        android:hint="请输入名字" />    <EditText        android:id="@+id/et_email"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:gravity="center_horizontal"        android:hint="请输入Email" />    <Button        android:id="@+id/insertContact"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickInsertContact"        android:text="增加一个联系人" />    <Button        android:id="@+id/getAllContacts"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickGetAllContacts"        android:text="检索所有联系人" />    <Button        android:id="@+id/getContacts"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickGetContact"        android:text="检索单个联系人" />    <Button        android:id="@+id/updateContact"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickUpdateContact"        android:text="更新联系人" />    <Button        android:id="@+id/deleteContact"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickDeleteContact"        android:text="删除联系人" /> <Button        android:id="@+id/bindDatabase"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:onClick="onClickBindDatabase"        android:text="捆绑数据库" />        <TextView        android:id="@+id/display"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:text="显示消息"        android:textColor="#EE1100"         android:gravity="center"/></LinearLayout>

DBAdapter.java

import java.sql.SQLException;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;public class DBAdapter {static final String KEY_ROWID = "_id";static final String KEY_NAME = "name";static final String KEY_EMAIL = "email";static final String TAG = "DBAdapt";static final String DATABASE_NAME = "MyDB.txt";static final String DATABASE_TABLE = "contacts";static final int DATABASE_VERSIOIN = 1;static final String DATABASE_CREATE = "CREATE TABLE contacts(_id,INTEGER PRIMARY KEY,"+"name TEXT NOT NULL,email TEXT NOT NULL)";final Context context;MyDatabaseHelper DBHelper;SQLiteDatabase db;public DBAdapter(Context context){this.context = context;DBHelper = new MyDatabaseHelper(context);}public static void main(String[] args) {// TODO Auto-generated method stub}private static  class MyDatabaseHelper extends SQLiteOpenHelper{public MyDatabaseHelper(Context context, String name,CursorFactory factory, int version) {super(context, name, factory, version);// TODO Auto-generated constructor stub}public MyDatabaseHelper(Context context){//为了方便，重载构造方法super(context, DATABASE_NAME, null, DATABASE_VERSIOIN);}@Overridepublic void onCreate(SQLiteDatabase db) {db.execSQL(DATABASE_CREATE);}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {Log.w(TAG, "Upgrding database from version"+"oldVersion"+"to"+"newVersion"+",which will destroy all old data");db.execSQL("DROP TABLE IF EXISTS contacts");onCreate(db);}}public DBAdapter open() throws SQLException{db = DBHelper.getWritableDatabase();return this;}public void close(){DBHelper.close();}public long insertContact(String name, String email){ContentValues values = new ContentValues();values.put(KEY_NAME, name);values.put(KEY_EMAIL, email);return db.insert(DATABASE_TABLE, null, values);}public boolean deleteContact(long rowId){return db.delete(DATABASE_TABLE, KEY_ROWID+"="+rowId,null) > 0;}public Cursor getAllContact(){return db.query(DATABASE_TABLE, null,null , null, null, null, null);}public Cursor getContact(long rowId) throws SQLException{Cursor mCursor = db.query(true, DATABASE_TABLE, new String []{KEY_ROWID,KEY_NAME,KEY_EMAIL}, KEY_ROWID+"="+rowId, null, null, null, null, null);if (mCursor != null) {mCursor.moveToFirst();}return mCursor;}public boolean udataContact(long rowId,String name,String email){ContentValues args = new ContentValues();args.put(KEY_NAME,name);args.put(KEY_EMAIL, email);return db.update(DATABASE_TABLE, args, KEY_ROWID+"="+rowId, null) > 0;}}

DatabaseActivity.java

import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.sql.SQLException;import android.app.Activity;import android.database.Cursor;import android.os.Bundle;import android.view.View;import android.widget.EditText;import android.widget.TextView;import android.widget.Toast;public class DatabaseActivity extends Activity {private EditText editName,editEmail;private TextView display;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_database);editName = (EditText)findViewById(R.id.et_name);editEmail = (EditText)findViewById(R.id.et_email);display = (TextView)findViewById(R.id.display);}//增加联系人public void onClickInsertContact(View v) throws SQLException{DBAdapter db = new DBAdapter(getBaseContext());db.open();String aName = editName.getText().toString();String aEmail = editEmail.getText().toString();long id = db.insertContact(aName, aEmail);Toast.makeText(getBaseContext(), "你已成功添加了一个联系人", Toast.LENGTH_SHORT).show();editName.setText("");editEmail.setText("");db.close();}//检索所有联系人public void onClickGetAllContacts(View v) throws SQLException{DBAdapter db = new DBAdapter(getBaseContext());db.open();Cursor c = db.getAllContact();if (c.moveToFirst()) {do {DisplayContact(c);} while (c.moveToNext());}}//检索单个联系人public void onClickGetContact(View v) throws SQLException{DBAdapter db = new DBAdapter(getBaseContext());db.open();Cursor c = db.getContact(2);if (c.moveToFirst()) {DisplayContact(c);}else{Toast.makeText(getBaseContext(), "找不到任何联系人", Toast.LENGTH_SHORT).show();}db.close();}//更新联系人public void onClickUpdateContact(View v) throws SQLException{DBAdapter db = new DBAdapter(getBaseContext());db.open();if (db.udataContact(1, "欧阳锋", "[e-mail]")) {Toast.makeText(getBaseContext(), "更新成功！", Toast.LENGTH_LONG).show();}else {Toast.makeText(getBaseContext(), "更新失败！", Toast.LENGTH_SHORT).show();}db.close();}//删除联系人public void updateDatabseupdateDatabse(View v) throws SQLException{DBAdapter db = new DBAdapter(getBaseContext());db.open();if (db.deleteContact(1)) {Toast.makeText(getBaseContext(), "删除成功!", Toast.LENGTH_SHORT).show();}else {Toast.makeText(getBaseContext(), "删除失败！", Toast.LENGTH_SHORT).show();}db.close();}//捆绑一个数据库public void onClickBindDatabase(View v) throws FileNotFoundException, SQLException{DBAdapter db = new DBAdapter(getBaseContext());try {String destPath = "/data/data/"+getPackageName() +"/databases";File f = new File(destPath);if (!f.exists()) {f.mkdirs();f.createNewFile();CopyDB(getBaseContext().getAssets().open("mydb"),new FileOutputStream(destPath+"/MyDB.txt"));}} catch (IOException e) {e.printStackTrace();}db.open();Cursor c = db.getAllContact();if (c.moveToFirst()) {do {DisplayContact(c);} while (c.moveToNext());}db.close();}public void CopyDB(InputStream inputStream, OutputStream outputStream) throws IOException {byte[] buffer = new byte[1024];int length;while ((length = inputStream.read(buffer)) > 0) {outputStream.write(buffer,0,length);}inputStream.close();outputStream.close();}public void DisplayContact(Cursor c) {display.setText(c.getString(0)+c.getString(1)+"姓名: "+c.getString(2)+",E-mail: "+c.getString(3)+"\n");}}

对于这方法，我觉得自己java的IO流部分还是比较薄弱的，还是得补啊！学习是一条漫长的路，要有效率又不能浮躁！