diff --git a/源程序代码-小米便签-Notes-master/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java b/源程序代码-小米便签-Notes-master/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java index ffe5d57..f771a3d 100644 --- a/源程序代码-小米便签-Notes-master/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java +++ b/源程序代码-小米便签-Notes-master/Notes-master/src/net/micode/notes/data/NotesDatabaseHelper.java @@ -26,58 +26,61 @@ import net.micode.notes.data.Notes.DataColumns; import net.micode.notes.data.Notes.DataConstants; import net.micode.notes.data.Notes.NoteColumns; - +/** + * 小米便签数据库帮助类，负责数据库的创建和版本管理 + */ public class NotesDatabaseHelper extends SQLiteOpenHelper { + // 数据库名称 private static final String DB_NAME = "note.db"; - + // 当前数据库版本 private static final int DB_VERSION = 4; - + // 数据库表名定义接口 public interface TABLE { - public static final String NOTE = "note"; + public static final String NOTE = "note"; // 笔记表 - public static final String DATA = "data"; + public static final String DATA = "data"; // 数据表 } - private static final String TAG = "NotesDatabaseHelper"; - - private static NotesDatabaseHelper mInstance; + private static final String TAG = "NotesDatabaseHelper"; // 日志标签 + private static NotesDatabaseHelper mInstance; // 单例实例 + // 创建笔记表的SQL语句 private static final String CREATE_NOTE_TABLE_SQL = - "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" + + "CREATE TABLE " + TABLE.NOTE + "(" + + NoteColumns.ID + " INTEGER PRIMARY KEY," + // 主键ID + NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + // 父ID + NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," + // 提醒日期 + NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," +// 背景颜色ID + NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 创建时间 + NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," + // 是否有附件 + NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 修改时间 + NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," + // 笔记数量(针对文件夹) + NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," + // 内容摘要 + NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," + // 类型(笔记/文件夹) + NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," + // 小部件ID + NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," + // 小部件类型 + NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," + // 同步ID + NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," + // 本地修改标记 + NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + // 原始父ID + NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," + // Google任务ID + NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" + // 版本号 ")"; - + // 创建数据表的SQL语句 private static final String CREATE_DATA_TABLE_SQL = "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.ID + " INTEGER PRIMARY KEY," + // 主键ID + DataColumns.MIME_TYPE + " TEXT NOT NULL," + // MIME类型 + DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," + // 关联的笔记ID + NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 创建时间 + NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + // 修改时间 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 ''" + + DataColumns.DATA1 + " INTEGER," + // 通用数据列1 + DataColumns.DATA2 + " INTEGER," + // 通用数据列2 + DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," + // 通用数据列3 + DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," + // 通用数据列4 + DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" + // 通用数据列5 ")"; - + // 创建数据表笔记ID索引的SQL语句 private static final String CREATE_DATA_NOTE_ID_INDEX_SQL = "CREATE INDEX IF NOT EXISTS note_id_index ON " + TABLE.DATA + "(" + DataColumns.NOTE_ID + ");"; @@ -206,17 +209,24 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" + " END"; + /** + * 构造函数 + */ public NotesDatabaseHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } - + /** + * 创建笔记表 + */ public void createNoteTable(SQLiteDatabase db) { db.execSQL(CREATE_NOTE_TABLE_SQL); reCreateNoteTableTriggers(db); createSystemFolder(db); Log.d(TAG, "note table has been created"); } - + /** + * 重新创建笔记表相关的触发器 + */ private void reCreateNoteTableTriggers(SQLiteDatabase db) { db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update"); db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update"); @@ -234,7 +244,9 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER); db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER); } - + /** + * 创建系统文件夹 + */ private void createSystemFolder(SQLiteDatabase db) { ContentValues values = new ContentValues(); @@ -276,12 +288,15 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL); Log.d(TAG, "data table has been created"); } - + /** + * 重新创建数据表相关的触发器 + */ private void reCreateDataTableTriggers(SQLiteDatabase db) { + // 删除现有触发器 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"); - + // 重新创建触发器 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); @@ -296,6 +311,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { @Override public void onCreate(SQLiteDatabase db) { + // 创建数据库时调用，创建表和触发器 createNoteTable(db); createDataTable(db); } @@ -304,29 +320,29 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { boolean reCreateTriggers = false; boolean skipV2 = false; - + // 从版本1升级到版本2 if (oldVersion == 1) { upgradeToV2(db); skipV2 = true; // this upgrade including the upgrade from v2 to v3 oldVersion++; } - + // 从版本2升级到版本3 if (oldVersion == 2 && !skipV2) { upgradeToV3(db); reCreateTriggers = true; oldVersion++; } - + // 从版本3升级到版本4 if (oldVersion == 3) { upgradeToV4(db); oldVersion++; } - + // 如果需要，重新创建触发器 if (reCreateTriggers) { reCreateNoteTableTriggers(db); reCreateDataTableTriggers(db); } - + // 检查版本升级是否成功 if (oldVersion != newVersion) { throw new IllegalStateException("Upgrade notes database to version " + newVersion + "fails");