新批注了另外两个

data文件夹已批注完

src/main/java/net/micode/notes/data/NotesDatabaseHelper.java

@@ -27,7 +27,7 @@ import net.micode.notes.data.Notes.DataConstants;
 import net.micode.notes.data.Notes.NoteColumns;
 
 
-public class NotesDatabaseHelper extends SQLiteOpenHelper {
+public class NotesDatabaseHelper extends SQLiteOpenHelper { //定义数据库相关的名称以及标签
     private static final String DB_NAME = "note.db";
 
     private static final int DB_VERSION = 4;
@@ -42,7 +42,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
 
     private static NotesDatabaseHelper mInstance;
 
-    private static final String CREATE_NOTE_TABLE_SQL =
+    private static final String CREATE_NOTE_TABLE_SQL =//规范定义数据库存储信息的格式以及组成部分
         "CREATE TABLE " + TABLE.NOTE + "(" +
             NoteColumns.ID + " INTEGER PRIMARY KEY," +
             NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
@@ -85,7 +85,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when move note to the folder
      */
-    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =//设置触发器，在笔记集更新的时候增加数量1
         "CREATE TRIGGER increase_folder_count_on_update "+
         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
         " BEGIN " +
@@ -97,7 +97,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when move note from folder
      */
-    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =//类似的设置触发器，在笔记集更新的时候减少数量1
         "CREATE TRIGGER decrease_folder_count_on_update " +
         " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
         " BEGIN " +
@@ -110,7 +110,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Increase folder's note count when insert new note to the folder
      */
-    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =
+    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER =//设置触发器，在笔记集创建的时候增加数量1
         "CREATE TRIGGER increase_folder_count_on_insert " +
         " AFTER INSERT ON " + TABLE.NOTE +
         " BEGIN " +
@@ -122,7 +122,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Decrease folder's note count when delete note from the folder
      */
-    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =
+    private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER =//设置触发器，在笔记集删除文件的时候-1
         "CREATE TRIGGER decrease_folder_count_on_delete " +
         " AFTER DELETE ON " + TABLE.NOTE +
         " BEGIN " +
@@ -135,7 +135,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     /**
      * Update note's content when insert data with type {@link DataConstants#NOTE}
      */
-    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =
+    private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER =//设置触发器用于在笔记中数据更改时进行相应ID，字段等的更新
         "CREATE TRIGGER update_note_content_on_insert " +
         " AFTER INSERT ON " + TABLE.DATA +
         " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" +
@@ -210,14 +210,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
         super(context, DB_NAME, null, DB_VERSION);
     }
 
-    public void createNoteTable(SQLiteDatabase db) {
+    public void createNoteTable(SQLiteDatabase db) {//创建并管理日志信息表
         db.execSQL(CREATE_NOTE_TABLE_SQL);
         reCreateNoteTableTriggers(db);
         createSystemFolder(db);
         Log.d(TAG, "note table has been created");
     }
 
-    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
+    private void reCreateNoteTableTriggers(SQLiteDatabase db) {//重置触发器
         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");
@@ -301,7 +301,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper {
     }
 
     @Override
-    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {//用于检查并进行数据库版本的更新，保障版本控制
         boolean reCreateTriggers = false;
         boolean skipV2 = false;
 

src/main/java/net/micode/notes/data/NotesProvider.java

@@ -35,7 +35,7 @@ import net.micode.notes.data.Notes.NoteColumns;
 import net.micode.notes.data.NotesDatabaseHelper.TABLE;
 
 
-public class NotesProvider extends ContentProvider {
+public class NotesProvider extends ContentProvider {//定义URL以及匹配规则
     private static final UriMatcher mMatcher;
 
     private NotesDatabaseHelper mHelper;
@@ -86,12 +86,12 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
+    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,//执行数据库查询操作
             String sortOrder) {
         Cursor c = null;
         SQLiteDatabase db = mHelper.getReadableDatabase();
         String id = null;
-        switch (mMatcher.match(uri)) {
+        switch (mMatcher.match(uri)) {//匹配数据库查询关键字
             case URI_NOTE:
                 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
                         sortOrder);
@@ -148,7 +148,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public Uri insert(Uri uri, ContentValues values) {
+    public Uri insert(Uri uri, ContentValues values) {//insert向数据库中插入一条数据信息值
         SQLiteDatabase db = mHelper.getWritableDatabase();
         long dataId = 0, noteId = 0, insertedId = 0;
         switch (mMatcher.match(uri)) {
@@ -182,7 +182,8 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public int delete(Uri uri, String selection, String[] selectionArgs) {
+    public int delete(Uri uri, String selection, String[] selectionArgs) {//实现删除操作
+    /*这两个参数通常在一起使用，以定义一个特定的删除操作。selection 定义了哪些数据应该被删除，而 selectionArgs 为 selection 中的占位符提供了具体的值。*/
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();
@@ -228,7 +229,7 @@ public class NotesProvider extends ContentProvider {
     }
 
     @Override
-    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
+    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {//更新
         int count = 0;
         String id = null;
         SQLiteDatabase db = mHelper.getWritableDatabase();