/*
* Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.micode.notes.data;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import net.micode.notes.data.Notes.DataColumns;
import net.micode.notes.data.Notes.DataConstants;
import net.micode.notes.data.Notes.NoteColumns;
//引入Notes中接口
public class NotesDatabaseHelper extends SQLiteOpenHelper { //该类为便签SQL表的定义以及操作，便于进行文件夹与便签的各种操作，例如添加或删除的行为
private static final String DB_NAME = "note.db"; //数据库名称
private static final int DB_VERSION = 4; //数据库版本
public interface TABLE { //定义一个数据库表接口
public static final String NOTE = "note"; //便签名
public static final String DATA = "data"; //便签数据
}
private static final String TAG = "NotesDatabaseHelper"; //日志类型
private static NotesDatabaseHelper mInstance; //创建NotesDatabaseHelper类对象
private static final String CREATE_NOTE_TABLE_SQL = //SQL语句，创建便签表，包含ID、最后修改日期、背景颜色、便签数等在Notes类中的内容
"CREATE TABLE " + TABLE.NOTE + "(" +
NoteColumns.ID + " INTEGER PRIMARY KEY," +
NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," +
NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," +
NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," +
NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
")";
private static final String CREATE_DATA_TABLE_SQL = //创建数据表的SQL语句
"CREATE TABLE " + TABLE.DATA + "(" +
DataColumns.ID + " INTEGER PRIMARY KEY," +
DataColumns.MIME_TYPE + " TEXT NOT NULL," +
DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," +
NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," +
DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," +
DataColumns.DATA1 + " INTEGER," +
DataColumns.DATA2 + " INTEGER," +
DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," +
DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," +
DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" +
")";
private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
"CREATE INDEX IF NOT EXISTS note_id_index ON " +
TABLE.DATA + "(" + DataColumns.NOTE_ID + ");"; //创建查询操作表索引，用于查找
/**
* Increase folder's note count when move note to the folder
*/
private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
"CREATE TRIGGER increase_folder_count_on_update "+
" AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
" BEGIN " +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
" WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
" END"; //创建触发器，方便进行操作，当移动便签时统计新的父文件夹内便签数量
/**
* Decrease folder's note count when move note from folder
*/
private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
"CREATE TRIGGER decrease_folder_count_on_update " +
" AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
" BEGIN " +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
" WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
" AND " + NoteColumns.NOTES_COUNT + ">0" + ";" +
" END"; //与上一个方法作用相反，统计旧的父文件夹便签数量
/**
* Increase folder's note count when insert new note to the folder
*/
private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
"CREATE TRIGGER increase_folder_count_on_insert " +
" AFTER INSERT ON " + TABLE.NOTE +
" BEGIN " +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
" WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
" END"; //创建便签时增加统计数量
/**
* Decrease folder's note count when delete note from the folder
*/
private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
"CREATE TRIGGER decrease_folder_count_on_delete " +
" AFTER DELETE ON " + TABLE.NOTE +
" BEGIN " +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" +
" WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID +
" AND " + NoteColumns.NOTES_COUNT + ">0;" +
" END"; //删除时减少数量
/**
* Update note's content when insert data with type {@link DataConstants#NOTE}
*/
private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
"CREATE TRIGGER update_note_content_on_insert " +
" AFTER INSERT ON " + TABLE.DATA +
" WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
" BEGIN" +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
" WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
" END"; //更新便签数据时更改table表内容
/**
* Update note's content when data with {@link DataConstants#NOTE} type has changed
*/
private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER =
"CREATE TRIGGER update_note_content_on_update " +
" AFTER UPDATE ON " + TABLE.DATA +
" WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
" BEGIN" +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT +
" WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" +
" END"; //改变便签数据时更改table表内容
/**
* Update note's content when data with {@link DataConstants#NOTE} type has deleted
*/
private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER =
"CREATE TRIGGER update_note_content_on_delete " +
" AFTER delete ON " + TABLE.DATA +
" WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
" BEGIN" +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.SNIPPET + "=''" +
" WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" +
" END"; //删除便签数据时改变table表内容
/**
* Delete datas belong to note which has been deleted
*/
private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER =
"CREATE TRIGGER delete_data_on_delete " +
" AFTER DELETE ON " + TABLE.NOTE +
" BEGIN" +
" DELETE FROM " + TABLE.DATA +
" WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" +
" END"; //删除便签时删除便签内容
/**
* Delete notes belong to folder which has been deleted
*/
private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER =
"CREATE TRIGGER folder_delete_notes_on_delete " +
" AFTER DELETE ON " + TABLE.NOTE +
" BEGIN" +
" DELETE FROM " + TABLE.NOTE +
" WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
" END"; //删除文件夹时删除内部的便签
/**
* Move notes belong to folder which has been moved to trash folder
*/
private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER =
"CREATE TRIGGER folder_move_notes_on_trash " +
" AFTER UPDATE ON " + TABLE.NOTE +
" WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
" BEGIN" +
" UPDATE " + TABLE.NOTE +
" SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER +
" WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" +
" END"; //移动便签的父文件夹时便签也一起更改
public NotesDatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
} //创建一个数据库
public void createNoteTable(SQLiteDatabase db) {
db.execSQL(CREATE_NOTE_TABLE_SQL);
reCreateNoteTableTriggers(db); //重新创建触发器
createSystemFolder(db); //创建系统文件夹
Log.d(TAG, "note table has been created"); //创建一个新的便签表，返回日志
}
private void reCreateNoteTableTriggers(SQLiteDatabase db) { //数据库对象DB
db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update");
db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete");
db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete");
db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert");
db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete");
db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash");
db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER);
db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER);
db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER);
db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER);
db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER);
} //用于执行SQL语句，运行重新创建便签表触发器函数
private void createSystemFolder(SQLiteDatabase db) { //创建系统级文件夹
ContentValues values = new ContentValues(); //为字典类创建对象
/**
* call record foler for call notes
*/
values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values); //为通讯便签创建记录文件夹，并添加键值对
/**
* root folder which is default folder
*/
values.clear();
values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values); //创建根文件夹，是默认的、最终的父文件夹
/**
* temporary folder which is used for moving note
*/
values.clear();
values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values); //为移动中的便签创建的临时文件夹
/**
* create trash folder
*/
values.clear();
values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values); //创建垃圾桶
}
public void createDataTable(SQLiteDatabase db) { //创建数据表
db.execSQL(CREATE_DATA_TABLE_SQL); //SQL输入保存的语句
reCreateDataTableTriggers(db);
db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
Log.d(TAG, "data table has been created"); //日志记录
}
private void reCreateDataTableTriggers(SQLiteDatabase db) { //为数据表重新创建触发器
db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert");
db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update");
db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete"); //删除触发器
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER);
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER);
db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER); //重新创建被删除的触发器
}
static synchronized NotesDatabaseHelper getInstance(Context context) {
if (mInstance == null) {
mInstance = new NotesDatabaseHelper(context);
}
return mInstance;
} //静态同步方法，用于返回NotesDatabaseHelper的对象实例mInstance
@Override
public void onCreate(SQLiteDatabase db) {
createNoteTable(db); //创建便签表
createDataTable(db); //创建数据表
} //用于初始化表
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { //用于检查并升级数据库版本
boolean reCreateTriggers = false;
boolean skipV2 = false;
if (oldVersion == 1) {
upgradeToV2(db);
skipV2 = true; // this upgrade including the upgrade from v2 to v3
oldVersion++;
} //检测到版本为1，升级版本
if (oldVersion == 2 && !skipV2) {
upgradeToV3(db);
reCreateTriggers = true; //重建触发器标志
oldVersion++; //检测到版本为2，升级版本
}
if (oldVersion == 3) {
upgradeToV4(db);
oldVersion++;
} //检测到版本为3，升级版本
if (reCreateTriggers) {
reCreateNoteTableTriggers(db);
reCreateDataTableTriggers(db);
} //进行触发器的重建
if (oldVersion != newVersion) {
throw new IllegalStateException("Upgrade notes database to version " + newVersion
+ "fails"); //版本不匹配则抛出异常
}
}
private void upgradeToV2(SQLiteDatabase db) { //升级版本并重建表
db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
createNoteTable(db);
createDataTable(db);
}
private void upgradeToV3(SQLiteDatabase db) {
// drop unused triggers
db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert");
db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete");
db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update");
// add a column for gtask id
db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+ " TEXT NOT NULL DEFAULT ''");
// add a trash system folder
ContentValues values = new ContentValues();
values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER);
values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
db.insert(TABLE.NOTE, null, values);
} //删除不用的触发器，并添加不为空的新列，添加键值对
private void upgradeToV4(SQLiteDatabase db) {
db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+ " INTEGER NOT NULL DEFAULT 0");
} //添加新的不为空的列
}