安卓初級教程（1）：@Database(1)

 package com.example.android.db01;

 import android.app.Activity;
 import android.content.ContentValues;
 import android.content.Context;
 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.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Spinner;
 import android.widget.AdapterView.OnItemSelectedListener;

 public class SQLiteTest extends Activity {
     OnClickListener listener_add = null;
     OnClickListener listener_update = null;
     OnClickListener listener_delete = null;
     OnClickListener listener_clear = null;
     Button button_add;
     Button button_update;
     Button button_delete;
     Button button_clear;
     DBConnection helper;
     public int id_this;
     public interface UserSchema {
             String TABLE_NAME = "Users";          //Table Name
             String ID = "_id";                    //ID
             String USER_NAME = "user_name";       //User Name
             String ADDRESS = "address";           //Address
             String TELEPHONE = "telephone";       //Phone Number
             String MAIL_ADDRESS = "mail_address"; //Mail Address
         }
     /** Called when the activity is first created. */
     //SQLiteTest
     @Override
     public void onCreate(final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
         final EditText mEditText01 = (EditText)findViewById(R.id.EditText01);
         final EditText mEditText02 = (EditText)findViewById(R.id.EditText02);
         final EditText mEditText03 = (EditText)findViewById(R.id.EditText03);
         final EditText mEditText04 = (EditText)findViewById(R.id.EditText04);

         helper = new DBConnection(this);
         final SQLiteDatabase db = helper.getWritableDatabase();
         final String[] FROM =
         {
             UserSchema.ID,
             UserSchema.USER_NAME,
             UserSchema.TELEPHONE,
             UserSchema.ADDRESS,
             UserSchema.MAIL_ADDRESS
         };
         //基本演算法，計算出db數數庫中總共有多少項數據列。
         Cursor c = db.query(UserSchema.TABLE_NAME, new String[] {UserSchema.USER_NAME}, null, null, null, null, null);
         c.moveToFirst();
         CharSequence[] list = new CharSequence[c.getCount()];
         for (int i = 0; i < list.length; i++) {
                 list[i] = c.getString(0);
                 c.moveToNext();
         }
         c.close();
         //
         Spinner spinner = (Spinner)findViewById(R.id.Spinner01);
         spinner.setAdapter(new ArrayAdapter<CharSequence>(this, android.R.layout.simple_spinner_item, list));

         spinner.setOnItemSelectedListener(new OnItemSelectedListener(){
             public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                 String user_name = ((Spinner)parent).getSelectedItem().toString();
                 Cursor c = db.query("Users", FROM , "user_name='" + user_name + "'", null, null, null, null);
                 c.moveToFirst();
                 id_this = Integer.parseInt(c.getString(0));
                 String user_name_this = c.getString(1);
                 String telephone_this = c.getString(2);
                 String address_this = c.getString(3);
                 String mail_address_this = c.getString(4);
                 c.close();
                 mEditText01.setText(user_name_this);
                 mEditText02.setText(telephone_this);
                 mEditText03.setText(address_this);
                 mEditText04.setText(mail_address_this);
             }
             public void onNothingSelected(AdapterView<?> parent) {
             }
         });
         //增加資料，定義項是ContentValues，獲取資料時使用put，然後用SQLiteDatanase的方法去開啟數據庫，最後將資料輸入database，用的方法是db.insert
         listener_add = new OnClickListener() {
             public void onClick(View v) {
                 ContentValues values = new ContentValues();
                 values.put(UserSchema.USER_NAME, mEditText01.getText().toString());
                 values.put(UserSchema.TELEPHONE, mEditText02.getText().toString());
                 values.put(UserSchema.ADDRESS, mEditText03.getText().toString());
                 values.put(UserSchema.MAIL_ADDRESS, mEditText04.getText().toString());
                 SQLiteDatabase db = helper.getWritableDatabase();
                 db.insert(UserSchema.TABLE_NAME, null, values);
                 db.close();
                 onCreate(savedInstanceState);
             }
         };
         //更新資料，定義項是ContentValues，獲取資料時使用put，然後用SQLiteDatanase的方法去開啟數據庫，最後將資料輸入database，用的方法是db.update
         listener_update = new OnClickListener() {
             public void onClick(View v) {
                 ContentValues values = new ContentValues();
                 values.put(UserSchema.USER_NAME, mEditText01.getText().toString());
                 values.put(UserSchema.TELEPHONE, mEditText02.getText().toString());
                 values.put(UserSchema.ADDRESS, mEditText03.getText().toString());
                 values.put(UserSchema.MAIL_ADDRESS, mEditText04.getText().toString());
                 String where = UserSchema.ID + " = " + id_this;
                 SQLiteDatabase db = helper.getWritableDatabase();
                 db.update(UserSchema.TABLE_NAME, values, where ,null);
                 db.close();
                 onCreate(savedInstanceState);
             }
         };
         //[Delete]
         listener_delete = new OnClickListener() {
             public void onClick(View v) {
                 String where = UserSchema.ID + " = " + id_this;
                 SQLiteDatabase db = helper.getWritableDatabase();
                 db.delete(UserSchema.TABLE_NAME, where ,null);
                 db.close();
                 onCreate(savedInstanceState);
             }
         };
         //[Clear]
         listener_clear = new OnClickListener() {
             public void onClick(View v) {
                 mEditText01.setText("");
                 mEditText02.setText("");
                 mEditText03.setText("");
                 mEditText04.setText("");
             }
         };
         //BUTTON0i,i=1,2,3,4 OnClickListener
         button_add = (Button)findViewById(R.id.Button01);
         button_add.setOnClickListener(listener_add);
         button_update = (Button)findViewById(R.id.Button02);
         button_update.setOnClickListener(listener_update);
         button_delete = (Button)findViewById(R.id.Button03);
         button_delete.setOnClickListener(listener_delete);
         button_clear = (Button)findViewById(R.id.Button04);
         button_clear.setOnClickListener(listener_clear);
     }
     //SQLiteOpenHelper，創建資料庫
     public static class DBConnection extends SQLiteOpenHelper {
         private static final String DATABASE_NAME = "PhoneBookDB";
         private static final int DATABASE_VERSION = 1;
         private DBConnection(Context ctx) {
             super(ctx, DATABASE_NAME, null, DATABASE_VERSION);
         }
         public void onCreate(SQLiteDatabase db) {
             String sql = "CREATE TABLE " + UserSchema.TABLE_NAME + " ("
             + UserSchema.ID  + " INTEGER primary key autoincrement, "
             + UserSchema.USER_NAME + " text not null, "
             + UserSchema.TELEPHONE + " text not null, "
             + UserSchema.ADDRESS + " text not null, "
             + UserSchema.MAIL_ADDRESS + " text not null "+ ");";
             //Log.i("haiyang:createDB=", sql);
             db.execSQL(sql);
         }
         public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
             // TODO Auto-generated method stub
         }
     }
 }