android-資料庫操作一

package com.yarin.android.Examples_06_05;


import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.os.Bundle;
import android.view.KeyEvent;
import android.widget.LinearLayout;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;


public class Activity01 extends Activity {
private static int miCount = 0;


/* 資料庫物件 */
private SQLiteDatabase mSQLiteDatabase = null;


/* 資料庫名 */
private final static String DATABASE_NAME = "Examples_06_05.db";
/* 表名 */
private final static String TABLE_NAME = "table1";


/* 表中的欄位 */
private final static String TABLE_ID = "_id";
private final static String TABLE_NUM = "num";
private final static String TABLE_DATA = "data";


/* 建立表的sql語句 */
private final static String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + " (" + TABLE_ID + " INTEGER PRIMARY KEY,"
+ TABLE_NUM + " INTERGER," + TABLE_DATA + " TEXT)";


/* 線性布局 */
LinearLayout m_LinearLayout = null;
/* 列表視圖-顯示資料庫中的資料 */
ListView m_ListView = null;


/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);


/* 建立LinearLayout布局對象 */
m_LinearLayout = new LinearLayout(this);
/* 設定布局LinearLayout的屬性 */
m_LinearLayout.setOrientation(LinearLayout.VERTICAL);
m_LinearLayout.setBackgroundColor(android.graphics.Color.BLACK);


/* 建立ListView對象 */
m_ListView = new ListView(this);
LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
m_ListView.setBackgroundColor(Color.BLACK);


/* 添加m_ListView到m_LinearLayout布局 */
m_LinearLayout.addView(m_ListView, param);


/* 設定顯示m_LinearLayout布局 */
setContentView(m_LinearLayout);


// 開啟已經存在的資料庫
mSQLiteDatabase = this.openOrCreateDatabase(DATABASE_NAME, MODE_PRIVATE, null);


// 擷取資料庫Phones的Cursor
try {
/* 在資料庫mSQLiteDatabase中建立一個表 */
mSQLiteDatabase.execSQL(CREATE_TABLE);
} catch (Exception e) {
UpdataAdapter();
}
}


public boolean onKeyUp(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_DPAD_LEFT:
AddData();
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
DeleteData();
break;
case KeyEvent.KEYCODE_1:
UpData();
break;
case KeyEvent.KEYCODE_2:
DeleteTable();
break;
case KeyEvent.KEYCODE_3:
DeleteDataBase();
break;
}
return true;
}


/* 刪除資料庫 */
public void DeleteDataBase() {
this.deleteDatabase(DATABASE_NAME);
this.finish();
}


/* 刪除一個表 */
public void DeleteTable() {
mSQLiteDatabase.execSQL("DROP TABLE " + TABLE_NAME);
this.finish();
}


/* 更新一條資料 */
public void UpData() {
ContentValues cv = new ContentValues();
cv.put(TABLE_NUM, miCount);
cv.put(TABLE_DATA, "修改後的資料" + miCount);


/* 更新資料 */
mSQLiteDatabase.update(TABLE_NAME, cv, TABLE_NUM + "=" + Integer.toString(miCount - 1), null);


UpdataAdapter();
}


/* 向表中添加一條資料 */
public void AddData() {
ContentValues cv = new ContentValues();
cv.put(TABLE_NUM, miCount);
cv.put(TABLE_DATA, "測試資料庫資料" + miCount);
/* 插入資料 */
mSQLiteDatabase.insert(TABLE_NAME, null, cv);
miCount++;
UpdataAdapter();
}


/* 從表中刪除指定的一條資料 */
public void DeleteData() {


/* 刪除資料 */
mSQLiteDatabase.execSQL("DELETE FROM " + TABLE_NAME + " WHERE _id=" + Integer.toString(miCount));


miCount--;
if (miCount < 0) {
miCount = 0;
}
UpdataAdapter();
}


/* 更行試圖顯示 */
public void UpdataAdapter() {
// 擷取資料庫Phones的Cursor
Cursor cur = mSQLiteDatabase.query(TABLE_NAME, new String[] { TABLE_ID, TABLE_NUM, TABLE_DATA }, null, null,
null, null, null);


miCount = cur.getCount();
if (cur != null && cur.getCount() >= 0) {
// ListAdapter是ListView和後台資料的橋樑
ListAdapter adapter = new SimpleCursorAdapter(this,
// 定義List中每一行的顯示模板
// 表示每一行包含兩個資料項目
android.R.layout.simple_list_item_2,
// 資料庫的Cursor對象
cur,
// 從資料庫的TABLE_NUM和TABLE_DATA兩列中取資料
new String[] { TABLE_NUM, TABLE_DATA },
// 與NAME和NUMBER對應的Views
new int[] { android.R.id.text1, android.R.id.text2 });


/* 將adapter添加到m_ListView中 */
m_ListView.setAdapter(adapter);
}
}


/* 按鍵事件處理 */
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
/* 退出時，不要忘記關閉 */
mSQLiteDatabase.close();
this.finish();
return true;
}
return super.onKeyDown(keyCode, event);
}
}