diff --git a/migrations/initial.ts b/migrations/initial.ts
index eb630d9..6a8b075 100644
--- a/migrations/initial.ts
+++ b/migrations/initial.ts
@@ -29,7 +29,7 @@ export async function up(knex:Knex) {
         b.primary(["content_id","tag_name"]);
     });
     await knex.schema.createTable("permissions",b=>{
-        b.integer('username').unsigned().notNullable();
+        b.string('username').notNullable();
         b.string("name").notNullable();
         b.primary(["username","name"]);
         b.foreign('username').references('users.username');
diff --git a/src/db/contents.ts b/src/db/contents.ts
index 95ae9f4..67c92d5 100644
--- a/src/db/contents.ts
+++ b/src/db/contents.ts
@@ -40,18 +40,21 @@ class KnexContentsAccessor implements ContentAccessor{
         }
         return false;
     };
-    async findById(id:number,tagload?:boolean){
-        const s:Content[] = await this.knex.select("*").from("contents").where({id:id});
+    async findById(id:number,tagload?:boolean): Promise<Content|undefined>{
+        const s = await this.knex.select("*").from("contents").where({id:id});
         if(s.length === 0) return undefined;
         const first = s[0];
-        first.additional = JSON.parse((first.additional as unknown) as string)
-        first['tags'] = [];
+        let ret_tags:string[] = []
         if(tagload === true){
             const tags : DBTagContentRelation[] = await this.knex.select("*")
                 .from("content_tag_relation").where({content_id:first.id});
-            first.tags = tags.map(x=>x.tag_name);
+            ret_tags = tags.map(x=>x.tag_name);
         }
-        return first;
+        return {
+            tags:ret_tags,
+            additional: JSON.parse(first.additional || "{}"),
+            ...first
+        };
     };
     async findList(option?:QueryListOption){
         option = option || {};
@@ -115,11 +118,12 @@ class KnexContentsAccessor implements ContentAccessor{
         return result;
     };
     async findListByBasePath(path:string):Promise<Content[]>{
-        let results:Content[] = await this.knex.select("*").from("contents").where({basepath:path});
-        results.forEach(e => {
-            e.additional = JSON.parse((e.additional as unknown) as string);
-        });
-        return results;
+        let results = await this.knex.select("*").from("contents").where({basepath:path});
+        return results.map(x=>({
+            additional:JSON.parse(x.additional || "{}"),
+            tags:[],
+            ...x
+        }));
     }
     async update(c:Partial<Content> & { id:number }){
         const {id,tags,...rest} = c;
diff --git a/src/db/tag.ts b/src/db/tag.ts
index e992c9c..8e24c70 100644
--- a/src/db/tag.ts
+++ b/src/db/tag.ts
@@ -5,8 +5,9 @@ type DBTags = {
     name: string,
     description?: string
 }
+
 class KnexTagAccessor implements TagAccessor{
-    knex:Knex
+    knex:Knex<DBTags>
     constructor(knex:Knex){
         this.knex = knex;
     }
diff --git a/src/db/user.ts b/src/db/user.ts
index 1a2e529..a5df975 100644
--- a/src/db/user.ts
+++ b/src/db/user.ts
@@ -1,7 +1,7 @@
 import Knex from 'knex';
 import {IUser,UserCreateInput, UserAccessor, Password} from '../model/user';
 
-type PermissionTable={
+type PermissionTable = {
     username:string,
     name:string
 };
diff --git a/src/model/contents.ts b/src/model/contents.ts
index ceca139..dd380ed 100644
--- a/src/model/contents.ts
+++ b/src/model/contents.ts
@@ -11,7 +11,7 @@ export interface ContentContent{
     content_type    : string,
     basepath        : string,
     filename        : string,
-    hash?           : string,
+    content_hash?   : string,
     additional      : JSONMap,
     tags            : string[],//eager loading 
 }
@@ -21,7 +21,7 @@ export const MetaContentContent = {
     content_type  : "string",
     basepath      : "string",
     filename      : "string",
-    hash          : "string",
+    content_hash  : "string",
     additional    : "object",
     tags          : "string[]",
 }
diff --git a/src/types/db.d.ts b/src/types/db.d.ts
new file mode 100644
index 0000000..bd1b36f
--- /dev/null
+++ b/src/types/db.d.ts
@@ -0,0 +1,34 @@
+import Knex from "knex";
+
+declare module "knex" {
+  interface Tables {
+    tags: {
+      name: string;
+      description?: string;
+    };
+    users: {
+      username: string;
+      password_hash: string;
+      password_salt: string;
+    };
+    contents: {
+      id: number;
+      title: string;
+      content_type: string;
+      basepath: string;
+      filename: string;
+      content_hash?: string;
+      additional?: string; //eager loading
+    };
+    content_tag_relation: {
+      content_id: number;
+      tag_name: string;
+    };
+    permissions: {
+      username: string;
+      name: string;
+    };
+  }
+  namespace Knex {
+  }
+}