diff --git a/src/main/java/com/example/cosmos_serversb/entities/Group.java b/src/main/java/com/example/cosmos_serversb/entities/Group.java
index e774568..8aae1f5 100644
--- a/src/main/java/com/example/cosmos_serversb/entities/Group.java
+++ b/src/main/java/com/example/cosmos_serversb/entities/Group.java
@@ -3,16 +3,15 @@
 
 import com.example.cosmos_serversb.models.SessionManager;
 import com.example.cosmos_serversb.models.Users;
-import com.sun.corba.se.impl.orbutil.graph.Graph;
 import org.hibernate.Session;
 
-import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.Set;
 
 public class Group {
     private String gId;
     private String uri, name;
+    private long requestHash = 0;
     private Set<User> members = new HashSet<>();
     private Set<Request> requests;
 
@@ -58,6 +57,18 @@
         return name;
     }
 
+    public long getRequestHash() {
+        return requestHash;
+    }
+
+    private void setRequestHash(long hash) {
+        this.requestHash = hash;
+    }
+
+    public void updateRequestHash(Request request){
+        setRequestHash(getRequestHash()+1);
+    }
+
     public Set<Request> getRequests(){
         return requests;
     }
diff --git a/src/main/java/com/example/cosmos_serversb/jsons/GidUriJson.java b/src/main/java/com/example/cosmos_serversb/jsons/GidUriJson.java
index d40cd6f..0e8e1c0 100644
--- a/src/main/java/com/example/cosmos_serversb/jsons/GidUriJson.java
+++ b/src/main/java/com/example/cosmos_serversb/jsons/GidUriJson.java
@@ -6,6 +6,7 @@
     private String name;
     private String gId;
     private String uri;
+    private Long requestHash;
 
     public GidUriJson(){
 
@@ -15,6 +16,7 @@
         setName(group.getName());
         setgId(group.getgId());
         setUri(group.getUri());
+        setRequestHash(group.getRequestHash());
     }
 
     private void setName(String name) { this.name = name; }
@@ -37,4 +39,11 @@
         return uri;
     }
 
+    private void setRequestHash(Long requestHash) {
+        this.requestHash = requestHash;
+    }
+
+    public long getRequestHash() {
+        return requestHash;
+    }
 }
diff --git a/src/main/java/com/example/cosmos_serversb/models/Groups.java b/src/main/java/com/example/cosmos_serversb/models/Groups.java
index cc6756c..1cda188 100644
--- a/src/main/java/com/example/cosmos_serversb/models/Groups.java
+++ b/src/main/java/com/example/cosmos_serversb/models/Groups.java
@@ -177,6 +177,7 @@
         Group editGroup = session.get(Group.class, gId);
         if(editGroup != null) {
             editGroup.addRequests(request);
+            editGroup.updateRequestHash(request);
             session.update(editGroup);
             return request;
         }
@@ -195,7 +196,7 @@
         return null;
     }
 
-    public static Request updateRequest(String gId, String rId, String uId, String product, String deadline, int location, boolean done){
+    public static RidUriJson updateRequest(String gId, String rId, String uId, String product, String deadline, int location, boolean done){
         if(product ==  null){
             return null; //not-null制約
         }
@@ -204,6 +205,8 @@
         if(editRequest != null){
             editRequest.update(uId, product, deadline, location, done);
             session.update(editRequest);
+            session.get(Group.class, gId).updateRequestHash(editRequest);
+            return new RidUriJson(editRequest);
         }
         //例外処理
         return null;
@@ -218,6 +221,7 @@
         Session session = SessionManager.getInstance().getSession();
         Request request = session.get(Request.class, rId);
         if(request != null) {
+            session.get(Group.class, gId).updateRequestHash(request);
             session.delete(request);
             return DeleteResult.SUCCESS;
         }
diff --git a/src/main/resources/Group.hbm.xml b/src/main/resources/Group.hbm.xml
index 061392e..026ce9f 100644
--- a/src/main/resources/Group.hbm.xml
+++ b/src/main/resources/Group.hbm.xml
@@ -17,6 +17,7 @@
         </id>
         <property name="uri" column="URI" not-null="true"/>
         <property name="name" column="NAME" not-null="true"/>
+        <property name="requestHash" column="REQUEST_HASH" type="java.lang.Long" not-null="true"/>
         <set name = "requests" cascade="all">
             <key column = "GID" not-null="true"/>
             <one-to-many class="Request"/>
diff --git a/src/main/resources/application-development.properties b/src/main/resources/application-development.properties
index 4c76c3b..91a9ee2 100644
--- a/src/main/resources/application-development.properties
+++ b/src/main/resources/application-development.properties
@@ -12,4 +12,4 @@
 #baseURI
 cosmos.baseURI=http://nitta-lab-www.is.konan-u.ac.jp/
 cosmos.appName=cosmsos
-cosmos.URL=${cosmos.baseURI}${cosmos.appName}
\ No newline at end of file
+cosmos.URL=${cosmos.baseURI}${cosmos.appName}