diff --git a/src/db/doc.ts b/src/db/doc.ts
index 85af977..1dc6699 100644
--- a/src/db/doc.ts
+++ b/src/db/doc.ts
@@ -15,6 +15,9 @@ class KnexDocumentAccessor implements DocumentAccessor{
         this.knex = knex;
         this.tagController = createKnexTagController(knex);
     }
+    async search(search_word: string): Promise<Document[]>{
+        throw new Error("Not implemented");
+    }
     async addList(content_list: DocumentBody[]):Promise<number[]>{
         return await this.knex.transaction(async (trx)=>{
             //add tags
diff --git a/src/model/doc.ts b/src/model/doc.ts
index d57976c..4b34fe3 100644
--- a/src/model/doc.ts
+++ b/src/model/doc.ts
@@ -94,6 +94,10 @@ export interface DocumentAccessor{
      * find deleted content
      */
     findDeleted:(content_type:string)=>Promise<Document[]>;
+    /**
+     * search by in document
+     */
+    search:(search_word:string)=>Promise<Document[]>
     /**
      * update document except tag.
      */