diff --git a/src/data/Notes.java b/src/data/Notes.java
index f240604..b3b44f3 100644
--- a/src/data/Notes.java
+++ b/src/data/Notes.java
@@ -17,9 +17,11 @@
 package net.micode.notes.data;
 
 import android.net.Uri;
+// Notes 类中定义了很多常量，这些常量大多是int型和string型
 public class Notes {
     public static final String AUTHORITY = "micode_notes";
     public static final String TAG = "Notes";
+    //以下三个常量对NoteColumns.TYPE的值进行设置时会用到
     public static final int TYPE_NOTE     = 0;
     public static final int TYPE_FOLDER   = 1;
     public static final int TYPE_SYSTEM   = 2;
@@ -54,13 +56,15 @@ public class Notes {
     /**
      * Uri to query all notes and folders
      */
+    //定义查询便签和文件夹的指针。
     public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
 
     /**
      * Uri to query data
      */
+    //定义查找数据的指针。
     public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
-
+    // 定义NoteColumns的常量,用于后面创建数据库的表头
     public interface NoteColumns {
         /**
          * The unique ID for a row
@@ -72,7 +76,7 @@ public class Notes {
          * The parent's id for note or folder
          * <P> Type: INTEGER (long) </P>
          */
-        public static final String PARENT_ID = "parent_id";
+        public static final String PARENT_ID = "parent_id";//为什么会有parent_id
 
         /**
          * Created data for note or folder
@@ -140,7 +144,7 @@ public class Notes {
          * The last sync id
          * <P> Type: INTEGER (long) </P>
          */
-        public static final String SYNC_ID = "sync_id";
+        public static final String SYNC_ID = "sync_id";//同步
 
         /**
          * Sign to indicate local modified or not
@@ -165,8 +169,9 @@ public class Notes {
          * <P> Type : INTEGER (long) </P>
          */
         public static final String VERSION = "version";
-    }
+    }//这些常量主要是定义便签的属性的。
 
+    // 定义DataColumns的常量,用于后面创建数据库的表头
     public interface DataColumns {
         /**
          * The unique ID for a row
@@ -239,7 +244,7 @@ public class Notes {
          * <P> Type: TEXT </P>
          */
         public static final String DATA5 = "data5";
-    }
+    }//主要是定义存储便签内容数据的
 
     public static final class TextNote implements DataColumns {
         /**
@@ -255,7 +260,7 @@ public class Notes {
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";
 
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");
-    }
+    }//文本内容的数据结构
 
     public static final class CallNote implements DataColumns {
         /**
@@ -275,5 +280,5 @@ public class Notes {
         public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";
 
         public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");
-    }
+    }//电话内容的数据结构
 }