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diff --git a/src/Contact.java b/src/Contact.java
new file mode 100644
index 0000000..d3629a4
--- /dev/null
+++ b/src/Contact.java
@@ -0,0 +1,98 @@
+/*
+ * 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.Context;
+import android.database.Cursor;
+import android.provider.ContactsContract.CommonDataKinds.Phone;
+import android.provider.ContactsContract.Data;
+import android.telephony.PhoneNumberUtils;
+import android.util.Log;
+
+import java.util.HashMap;
+
+public class Contact {
+    // 存储联系人信息的缓存，以电话号码为键，联系人名称为值
+    private static HashMap<String, String> sContactCache;
+    // 日志标记，用于在日志输出中标识该类
+    private static final String TAG = "Contact";
+
+    // 用于查询联系人信息的 SQL 语句模板
+    // 该语句将根据电话号码匹配联系人，并筛选出联系人显示名称
+    // 涉及 Phone.NUMBER 用于匹配电话号码
+    // Data.MIMETYPE 用于匹配联系人数据的 MIME 类型，确保是电话号码类型的数据
+    // Data.RAW_CONTACT_ID 用于从 phone_lookup 表中筛选相关的原始联系人 ID
+    private static final String CALLER_ID_SELECTION = "PHONE_NUMBERS_EQUAL(" + Phone.NUMBER
+            + ",?) AND " + Data.MIMETYPE + "='" + Phone.CONTENT_ITEM_TYPE + "'"
+            + " AND " + Data.RAW_CONTACT_ID + " IN "
+            + "(SELECT raw_contact_id "
+            + " FROM phone_lookup"
+            + " WHERE min_match = '+')";
+
+    // 根据传入的上下文和电话号码查找联系人名称
+    public static String getContact(Context context, String phoneNumber) {
+        // 检查缓存是否为空，如果为空则创建一个新的 HashMap 作为缓存
+        if (sContactCache == null) {
+            sContactCache = new HashMap<String, String>();
+        }
+
+        // 检查缓存中是否已经存在该电话号码对应的联系人信息
+        if (sContactCache.containsKey(phoneNumber)) {
+            // 如果缓存中存在，则直接返回联系人名称
+            return sContactCache.get(phoneNumber);
+        }
+
+        // 替换 CALLER_ID_SELECTION 中的占位符 '+'，使用 PhoneNumberUtils 工具将电话号码转换为匹配模式
+        String selection = CALLER_ID_SELECTION.replace("+",
+                PhoneNumberUtils.toCallerIDMinMatch(phoneNumber));
+        // 使用上下文的 ContentResolver 进行查询操作
+        // 查询 Data.CONTENT_URI 以获取联系人信息
+        // 仅查询 Phone.DISPLAY_NAME 列
+        // 使用 selection 作为查询条件，phoneNumber 作为查询参数
+        Cursor cursor = context.getContentResolver().query(
+                Data.CONTENT_URI,
+                new String[]{Phone.DISPLAY_NAME},
+                selection,
+                new String[]{phoneNumber},
+                null);
+
+        // 如果游标不为空且可以移动到第一条记录
+        if (cursor!= null && cursor.moveToFirst()) {
+            try {
+                // 从游标中获取联系人名称
+                String name = cursor.getString(0);
+                // 将联系人信息添加到缓存中，方便下次使用
+                sContactCache.put(phoneNumber, name);
+                // 返回联系人名称
+                return name;
+            } catch (IndexOutOfBoundsException e) {
+                // 捕获并打印索引越界异常
+                Log.e(TAG, "Cursor get string error " + e.toString());
+                // 返回 null 表示查找失败
+                return null;
+            } finally {
+                // 确保在任何情况下都关闭游标，释放资源
+                cursor.close();
+            }
+        } else {
+            // 如果没有找到匹配的联系人，记录日志信息
+            Log.d(TAG, "No contact matched with number:" + phoneNumber);
+            // 返回 null 表示查找失败
+            return null;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/MetaData.java b/src/MetaData.java
new file mode 100644
index 0000000..9abdd21
--- /dev/null
+++ b/src/MetaData.java
@@ -0,0 +1,95 @@
+/*
+ * 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.gtask.data;
+
+import android.database.Cursor;
+import android.util.Log;
+
+import net.micode.notes.tool.GTaskStringUtils;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+
+public class MetaData extends Task {
+    // 日志标记，用于在日志输出中识别该类
+    private final static String TAG = MetaData.class.getSimpleName();
+    // 存储相关的 Gid
+    private String mRelatedGid = null;
+
+    // 设置元数据
+    public void setMeta(String gid, JSONObject metaInfo) {
+        try {
+            // 将 Gid 放入元信息的 JSON 对象中
+            metaInfo.put(GTaskStringUtils.META_HEAD_GTASK_ID, gid);
+        } catch (JSONException e) {
+            // 记录放入 Gid 失败的错误日志
+            Log.e(TAG, "failed to put related gid");
+        }
+        // 将元信息转换为字符串并设置为笔记
+        setNotes(metaInfo.toString());
+        // 设置名称为元笔记名称
+        setName(GTaskStringUtils.META_NOTE_NAME);
+    }
+
+    // 获取相关的 Gid
+    public String getRelatedGid() {
+        return mRelatedGid;
+    }
+
+    @Override
+    // 判断是否值得保存
+    public boolean isWorthSaving() {
+        return getNotes()!= null;
+    }
+
+    @Override
+    // 根据远程 JSON 数据设置内容
+    public void setContentByRemoteJSON(JSONObject js) {
+        super.setContentByRemoteJSON(js);
+        if (getNotes()!= null) {
+            try {
+                // 将笔记内容解析为 JSON 对象，并从中获取相关的 Gid
+                JSONObject metaInfo = new JSONObject(getNotes().trim());
+                mRelatedGid = metaInfo.getString(GTaskStringUtils.META_HEAD_GTASK_ID);
+            } catch (JSONException e) {
+                // 记录获取 Gid 失败的警告日志，并将相关 Gid 设为 null
+                Log.w(TAG, "failed to get related gid");
+                mRelatedGid = null;
+            }
+        }
+    }
+
+    @Override
+    // 不允许调用此方法，会抛出异常
+    public void setContentByLocalJSON(JSONObject js) {
+        // 此函数不应该被调用
+        throw new IllegalAccessError("MetaData:setContentByLocalJSON should not be called");
+    }
+
+    @Override
+    // 不允许调用此方法，会抛出异常
+    public JSONObject getLocalJSONFromContent() {
+        throw new IllegalAccessError("MetaData:getLocalJSONFromContent should not be called");
+    }
+
+    @Override
+    // 不允许调用此方法，会抛出异常
+    public int getSyncAction(Cursor c) {
+        throw new IllegalAccessError("MetaData:getSyncAction should not be called");
+    }
+}
\ No newline at end of file
diff --git a/src/Notes.java b/src/Notes.java
new file mode 100644
index 0000000..3ef00b6
--- /dev/null
+++ b/src/Notes.java
@@ -0,0 +1,156 @@
+/*
+ * 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.net.Uri;
+
+public class Notes {
+    // 内容提供者的授权字符串，用于标识此 Notes 类提供的内容
+    public static final String AUTHORITY = "micode_notes";
+    // 日志标记，可用于在日志输出中识别该类
+    public static final String TAG = "Notes";
+    // 不同类型的笔记或文件夹的标识符
+    public static final int TYPE_NOTE = 0;
+    public static final int TYPE_FOLDER = 1;
+    public static final int TYPE_SYSTEM = 2;
+
+    // 系统文件夹的标识符
+    // 根文件夹的默认标识符
+    public static final int ID_ROOT_FOLDER = 0;
+    // 临时文件夹的标识符，用于存储无归属文件夹的笔记
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    // 存储通话记录的文件夹标识符
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    // 回收站文件夹的标识符
+    public static final int ID_TRASH_FOLER = -3;
+
+    // 用于存储笔记提醒日期的意图额外信息键
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";
+    // 用于存储笔记背景颜色 ID 的意图额外信息键
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    // 用于存储笔记部件 ID 的意图额外信息键
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";
+    // 用于存储笔记部件类型的意图额外信息键
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    // 用于存储文件夹 ID 的意图额外信息键
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
+    // 用于存储通话日期的意图额外信息键
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";
+
+    // 不同类型的部件标识符
+    public static final int TYPE_WIDGET_INVALIDE = -1;
+    public static final int TYPE_WIDGET_2X = 0;
+    public static final int TYPE_WIDGET_4X = 1;
+
+    public static class DataConstants {
+        // 文本笔记和通话笔记的内容项类型
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;
+    }
+
+    // 用于查询所有笔记和文件夹的 URI
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+    // 用于查询数据的 URI
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
+    public interface NoteColumns {
+        // 行的唯一 ID，数据类型为长整型
+        public static final String ID = "_id";
+        // 笔记或文件夹的父 ID，数据类型为长整型
+        public static final String PARENT_ID = "parent_id";
+        // 笔记或文件夹的创建日期，数据类型为长整型
+        public static final String CREATED_DATE = "created_date";
+        // 笔记或文件夹的最新修改日期，数据类型为长整型
+        public static final String MODIFIED_DATE = "modified_date";
+        // 笔记的提醒日期，数据类型为长整型
+        public static final String ALERTED_DATE = "alert_date";
+        // 文件夹的名称或笔记的文本内容，数据类型为文本
+        public static final String SNIPPET = "snippet";
+        // 笔记的部件 ID，数据类型为长整型
+        public static final String WIDGET_ID = "widget_id";
+        // 笔记的部件类型，数据类型为长整型
+        public static final String WIDGET_TYPE = "widget_type";
+        // 笔记的背景颜色 ID，数据类型为长整型
+        public static final String BG_COLOR_ID = "bg_color_id";
+        // 表示笔记是否有附件，数据类型为整型
+        public static final String HAS_ATTACHMENT = "has_attachment";
+        // 文件夹中的笔记数量，数据类型为长整型
+        public static final String NOTES_COUNT = "notes_count";
+        // 表示文件类型（文件夹或笔记），数据类型为整型
+        public static final String TYPE = "type";
+        // 最后同步的 ID，数据类型为长整型
+        public static final String SYNC_ID = "sync_id";
+        // 表示是否本地修改，数据类型为整型
+        public static final String LOCAL_MODIFIED = "local_modified";
+        // 移动到临时文件夹之前的原始父 ID，数据类型为整型
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";
+        // 可能与 gtask 相关的 ID，数据类型为文本
+        public static final String GTASK_ID = "gtask_id";
+        // 版本代码，数据类型为长整型
+        public static final String VERSION = "version";
+    }
+
+    public interface DataColumns {
+        // 行的唯一 ID，数据类型为长整型
+        public static final String ID = "_id";
+        // 行所代表的项的 MIME 类型，数据类型为文本
+        public static final String MIME_TYPE = "mime_type";
+        // 此数据所属笔记的引用 ID，数据类型为长整型
+        public static final String NOTE_ID = "note_id";
+        // 笔记或文件夹的创建日期，数据类型为长整型
+        public static final String CREATED_DATE = "created_date";
+        // 笔记或文件夹的最新修改日期，数据类型为长整型
+        public static final String MODIFIED_DATE = "modified_date";
+        // 数据的内容，数据类型为文本
+        public static final String CONTENT = "content";
+        // 通用数据列，其含义因 MIME 类型而异，用于整数数据类型，数据类型为整型
+        public static final String DATA1 = "data1";
+        // 通用数据列，其含义因 MIME 类型而异，用于整数数据类型，数据类型为整型
+        public static final String DATA2 = "data2";
+        // 通用数据列，其含义因 MIME 类型而异，用于文本数据类型，数据类型为文本
+        public static final String DATA3 = "data3";
+        // 通用数据列，其含义因 MIME 类型而异，用于文本数据类型，数据类型为文本
+        public static final String DATA4 = "data4";
+        // 通用数据列，其含义因 MIME 类型而异，用于文本数据类型，数据类型为文本
+        public static final String DATA5 = "data5";
+    }
+
+    public static final class TextNote implements DataColumns {
+        // 表示文本是否处于检查列表模式的模式，数据类型为整型（1 表示检查列表模式，0 表示正常模式）
+        public static final String MODE = DATA1;
+        public static final int MODE_CHECK_LIST = 1;
+        // 表示文本笔记的内容类型，一般用于表示目录的 MIME 类型
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";
+        // 表示文本笔记的内容项类型，一般用于表示单个项的 MIME 类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
+        // 用于访问文本笔记的 URI
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
+    }
+
+    public static final class CallNote implements DataColumns {
+        // 通话记录的通话日期，数据类型为长整型
+        public static final String CALL_DATE = DATA1;
+        // 通话记录的电话号码，数据类型为文本
+        public static final String PHONE_NUMBER = DATA3;
+        // 表示通话笔记的内容类型，一般用于表示目录的 MIME 类型
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";
+        // 表示通话笔记的内容项类型，一般用于表示单个项的 MIME 类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
+        // 用于访问通话笔记的 URI
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
+    }
+}
\ No newline at end of file
diff --git a/src/NotesDatabaseHelper.java b/src/NotesDatabaseHelper.java
new file mode 100644
index 0000000..aa6621a
--- /dev/null
+++ b/src/NotesDatabaseHelper.java
@@ -0,0 +1,364 @@
+/*
+ * 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;
+
+
+public class NotesDatabaseHelper extends SQLiteOpenHelper {
+    // 数据库名称
+    private static final String DB_NAME = "note.db";
+    // 数据库版本号
+    private static final int DB_VERSION = 4;
+
+    public interface TABLE {
+        // 存储笔记的表名
+        public static final String NOTE = "note";
+        // 存储数据的表名
+        public static final String DATA = "data";
+    }
+
+    // 日志标记，用于在日志输出中识别该类
+    private static final String TAG = "NotesDatabaseHelper";
+    // 单例模式的实例
+    private static NotesDatabaseHelper mInstance;
+
+    // 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" +
+                    ")";
+
+    // 创建数据存储表的 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.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 ''" +
+                    ")";
+
+    // 创建数据表的笔记 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 + ");";
+
+    // 当笔记移动到文件夹时，增加文件夹中笔记计数的触发器
+    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";
+
+    // 当笔记从文件夹中移出时，减少文件夹中笔记计数的触发器
+    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";
+
+    // 当插入新笔记到文件夹时，增加文件夹中笔记计数的触发器
+    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";
+
+    // 当从文件夹中删除笔记时，减少文件夹中笔记计数的触发器
+    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";
+
+    // 当插入数据类型为 {@link DataConstants#NOTE} 时，更新笔记内容的触发器
+    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";
+
+    // 当数据类型为 {@link DataConstants#NOTE} 的数据更新时，更新笔记内容的触发器
+    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";
+
+    // 当数据类型为 {@link DataConstants#NOTE} 的数据删除时，更新笔记内容的触发器
+    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";
+
+    // 当笔记被删除时，删除属于该笔记的数据的触发器
+    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";
+
+    // 当文件夹被删除时，删除属于该文件夹的笔记的触发器
+    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";
+
+    // 当文件夹被移动到回收站时，移动属于该文件夹的笔记到回收站的触发器
+    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";
+
+    // 构造函数，接收上下文作为参数
+    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");
+        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);
+    }
+
+    // 创建系统文件夹
+    private void createSystemFolder(SQLiteDatabase db) {
+        ContentValues values = new ContentValues();
+
+        // 创建通话记录文件夹
+        /**
+         * 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);
+
+        // 创建根文件夹
+        /**
+         * 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);
+
+        // 创建临时文件夹
+        /**
+         * 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);
+
+        // 创建回收站文件夹
+        /**
+         * 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);
+    }
+
+    // 创建数据存储表
+    public void createDataTable(SQLiteDatabase db) {
+        db.execSQL(CREATE_DATA_TABLE_SQL);
+        reCreateDataTableTriggers(db);
+        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
+        Log.d(TAG, "data table has been created");
+    }
+
+    // 重新创建数据存储表的触发器
+    private void reCreateDataTableTriggers(SQLiteDatabase db) {
+        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");
+
+        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);
+    }
+
+    // 单例模式的实例获取方法
+    static synchronized NotesDatabaseHelper getInstance(Context context) {
+        if (mInstance == null) {
+            mInstance = new NotesDatabaseHelper(context);
+        }
+        return mInstance;
+    }
+
+    // 数据库创建时调用
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    // 数据库升级时调用
+    @Override
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        boolean reCreateTriggers = false;
+        boolean skipV2 = false;
+
+        if (oldVersion == 1) {
+            upgradeToV2(db);
+            skipV2 = true; // 此升级包含从 v2 到 v3 的升级
+            oldVersion++;
+        }
+
+        if (oldVersion == 2 &&!skipV2) {
+            upgradeToV3(db);
+            reCreateTriggers = true;
+            oldVersion++;
+        }
+
+        if (oldVersion == 3) {
+            upgradeToV4(db);
+            oldVersion++;
+        }
+
+        if (reCreateTriggers) {
+            reCreateNoteTableTriggers(db);
+            reCreateDataTableTriggers(db);
+        }
+
+        if (oldVersion!= newVersion) {
+            throw new IllegalStateException("Upgrade notes database to version " + newVersion
+                    + "fails");
+        }
+    }
+
+    // 从版本 1 升级到版本 2 的操作
+    private void upgradeToV2(SQLiteDatabase db) {
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE);
+        db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA);
+        createNoteTable(db);
+        createDataTable(db);
+    }
+
+    // 从版本 2 升级到版本 3 的操作
+    private void upgradeToV3(SQLiteDatabase db) {
+        // 删除未使用的触发器
+        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");
+        // 为笔记表添加 gtask id 列
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID
+                + " TEXT NOT NULL DEFAULT ''");
+        // 添加一个回收站系统文件夹
+        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);
+    }
+
+    // 从版本 3 升级到版本 4 的操作
+    private void upgradeToV4(SQLiteDatabase db) {
+        db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION
+                + " INTEGER NOT NULL DEFAULT 0");
+    }
+}
\ No newline at end of file
diff --git a/src/NotesProvider.java b/src/NotesProvider.java
new file mode 100644
index 0000000..7a5a487
--- /dev/null
+++ b/src/NotesProvider.java
@@ -0,0 +1,328 @@
+/*
+ * 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.app.SearchManager;
+import android.content.ContentProvider;
+import android.content.ContentUris;
+import android.content.ContentValues;
+import android.content.Intent;
+import android.content.UriMatcher;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.net.Uri;
+import android.text.TextUtils;
+import android.util.Log;
+
+import net.micode.notes.R;
+import net.micode.notes.data.Notes.DataColumns;
+import net.micode.notes.data.Notes.NoteColumns;
+import net.micode.notes.data.NotesDatabaseHelper.TABLE;
+
+
+public class NotesProvider extends ContentProvider {
+    // 用于匹配不同 URI 的 UriMatcher 实例
+    private static final UriMatcher mMatcher;
+    // 数据库帮助类的实例
+    private NotesDatabaseHelper mHelper;
+    // 日志标记，用于在日志输出中识别该类
+    private static final String TAG = "NotesProvider";
+    // 不同 URI 的匹配码
+    private static final int URI_NOTE = 1;
+    private static final int URI_NOTE_ITEM = 2;
+    private static final int URI_DATA = 3;
+    private static final int URI_DATA_ITEM = 4;
+    private static final int URI_SEARCH = 5;
+    private static final int URI_SEARCH_SUGGEST = 6;
+
+    static {
+        // 初始化 UriMatcher 并添加各种 URI 模式及对应的匹配码
+        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
+        mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);
+        mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);
+        mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);
+        mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);
+        mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);
+    }
+
+    // 搜索结果的投影查询语句，包含对换行符的处理和添加搜索相关的额外信息
+    private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","
+            + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","
+            + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","
+            + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","
+            + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","
+            + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","
+            + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;
+
+    // 搜索笔记摘要的查询语句，包含对笔记的筛选条件
+    private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION
+            + " FROM " + TABLE.NOTE
+            + " WHERE " + NoteColumns.SNIPPET + " LIKE?"
+            + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER
+            + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;
+
+    @Override
+    public boolean onCreate() {
+        // 获取数据库帮助类的实例
+        mHelper = NotesDatabaseHelper.getInstance(getContext());
+        return true;
+    }
+
+    @Override
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+                        String sortOrder) {
+        Cursor c = null;
+        SQLiteDatabase db = mHelper.getReadableDatabase();
+        String id = null;
+        // 根据不同的 URI 进行不同的查询操作
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                // 查询笔记表
+                c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_NOTE_ITEM:
+                // 查询单个笔记项
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_DATA:
+                // 查询数据存储表
+                c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
+                        sortOrder);
+                break;
+            case URI_DATA_ITEM:
+                // 查询单个数据项
+                id = uri.getPathSegments().get(1);
+                c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs, null, null, sortOrder);
+                break;
+            case URI_SEARCH:
+            case URI_SEARCH_SUGGEST:
+                // 处理搜索和搜索建议的查询，有一些限制和异常处理
+                if (sortOrder!= null || projection!= null) {
+                    throw new IllegalArgumentException(
+                            "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
+                }
+
+                String searchString = null;
+                if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
+                    if (uri.getPathSegments().size() > 1) {
+                        searchString = uri.getPathSegments().get(1);
+                    }
+                } else {
+                    searchString = uri.getQueryParameter("pattern");
+                }
+
+                if (TextUtils.isEmpty(searchString)) {
+                    return null;
+                }
+
+                try {
+                    searchString = String.format("%%%s%%", searchString);
+                    c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
+                            new String[] { searchString });
+                } catch (IllegalStateException ex) {
+                    Log.e(TAG, "got exception: " + ex.toString());
+                }
+                break;
+            default:
+                // 不匹配的 URI 抛出异常
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (c!= null) {
+            // 设置通知 URI，以便在数据变化时通知监听者
+            c.setNotificationUri(getContext().getContentResolver(), uri);
+        }
+        return c;
+    }
+
+    @Override
+    public Uri insert(Uri uri, ContentValues values) {
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        long dataId = 0, noteId = 0, insertedId = 0;
+        // 根据不同的 URI 进行插入操作
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                // 插入笔记
+                insertedId = noteId = db.insert(TABLE.NOTE, null, values);
+                break;
+            case URI_DATA:
+                // 插入数据，并检查是否包含笔记 ID
+                if (values.containsKey(DataColumns.NOTE_ID)) {
+                    noteId = values.getAsLong(DataColumns.NOTE_ID);
+                } else {
+                    Log.d(TAG, "Wrong data format without note id:" + values.toString());
+                }
+                insertedId = dataId = db.insert(TABLE.DATA, null, values);
+                break;
+            default:
+                // 不匹配的 URI 抛出异常
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        // 通知相关 URI 数据已改变
+        if (noteId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null);
+        }
+
+        if (dataId > 0) {
+            getContext().getContentResolver().notifyChange(
+                    ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null);
+        }
+
+        return ContentUris.withAppendedId(uri, insertedId);
+    }
+
+    @Override
+    public int delete(Uri uri, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean deleteData = false;
+        // 根据不同的 URI 进行删除操作
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                // 删除笔记
+                selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 ";
+                count = db.delete(TABLE.NOTE, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+                // 删除单个笔记项，不允许删除系统文件夹
+                id = uri.getPathSegments().get(1);
+                long noteId = Long.valueOf(id);
+                if (noteId <= 0) {
+                    break;
+                }
+                count = db.delete(TABLE.NOTE,
+                        NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+                // 删除数据存储表中的数据
+                count = db.delete(TABLE.DATA, selection, selectionArgs);
+                deleteData = true;
+                break;
+            case URI_DATA_ITEM:
+                // 删除单个数据项
+                id = uri.getPathSegments().get(1);
+                count = db.delete(TABLE.DATA,
+                        DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
+                deleteData = true;
+                break;
+            default:
+                // 不匹配的 URI 抛出异常
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+        if (count > 0) {
+            // 通知相关 URI 数据已改变
+            if (deleteData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    @Override
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+        int count = 0;
+        String id = null;
+        SQLiteDatabase db = mHelper.getWritableDatabase();
+        boolean updateData = false;
+        // 根据不同的 URI 进行更新操作
+        switch (mMatcher.match(uri)) {
+            case URI_NOTE:
+                // 更新笔记，增加笔记版本
+                increaseNoteVersion(-1, selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, selection, selectionArgs);
+                break;
+            case URI_NOTE_ITEM:
+                // 更新单个笔记项，增加笔记版本
+                id = uri.getPathSegments().get(1);
+                increaseNoteVersion(Long.valueOf(id), selection, selectionArgs);
+                count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                break;
+            case URI_DATA:
+                // 更新数据存储表中的数据
+                count = db.update(TABLE.DATA, values, selection, selectionArgs);
+                updateData = true;
+                break;
+            case URI_DATA_ITEM:
+                // 更新单个数据项
+                id = uri.getPathSegments().get(1);
+                count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
+                        + parseSelection(selection), selectionArgs);
+                updateData = true;
+                break;
+            default:
+                // 不匹配的 URI 抛出异常
+                throw new IllegalArgumentException("Unknown URI " + uri);
+        }
+
+        if (count > 0) {
+            // 通知相关 URI 数据已改变
+            if (updateData) {
+                getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
+            }
+            getContext().getContentResolver().notifyChange(uri, null);
+        }
+        return count;
+    }
+
+    // 解析选择条件，添加 AND 关键字
+    private String parseSelection(String selection) {
+        return (!TextUtils.isEmpty(selection)? " AND (" + selection + ')' : "");
+    }
+
+    // 增加笔记的版本号
+    private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
+        StringBuilder sql = new StringBuilder(120);
+        sql.append("UPDATE ");
+        sql.append(TABLE.NOTE);
+        sql.append(" SET ");
+        sql.append(NoteColumns.VERSION);
+        sql.append("=" + NoteColumns.VERSION + "+1 ");
+
+        if (id > 0 ||!TextUtils.isEmpty(selection)) {
+            sql.append(" WHERE ");
+        }
+        if (id > 0) {
+            sql.append(NoteColumns.ID + "=" + String.valueOf(id));
+        }
+        if (!TextUtils.isEmpty(selection)) {
+            String selectString = id > 0? parseSelection(selection) : selection;
+            for (String args : selectionArgs) {
+                selectString = selectString.replaceFirst("\\?", args);
+            }
+            sql.append(selectString);
+        }
+
+        mHelper.getWritableDatabase().execSQL(sql.toString());
+    }
+
+    @Override
+    public String getType(Uri uri) {
+        // 暂时未实现，返回 null
+        // TODO Auto-generated method stub
+        return null;
+    }
+}
\ No newline at end of file