diff --git a/app/src/main/java/io/legado/app/data/dao/BookChapterDao.kt b/app/src/main/java/io/legado/app/data/dao/BookChapterDao.kt
index a0b2b002f..7f42d74d8 100644
--- a/app/src/main/java/io/legado/app/data/dao/BookChapterDao.kt
+++ b/app/src/main/java/io/legado/app/data/dao/BookChapterDao.kt
@@ -1,5 +1,6 @@
 package io.legado.app.data.dao
 
+import androidx.paging.DataSource
 import androidx.room.Dao
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
@@ -9,6 +10,9 @@ import io.legado.app.data.entities.BookChapter
 @Dao
 interface BookChapterDao {
 
+    @Query("select * from chapters where bookUrl = :bookUrl")
+    fun observeByBook(bookUrl: String): DataSource.Factory<Int, BookChapter>
+
     @Query("select * from chapters where bookUrl = :bookUrl and `index` = :index")
     fun getChapter(bookUrl: String, index: Int): BookChapter?