diff --git a/src/handler/point.rs b/src/handler/point.rs
index 5de31ad..5ba5385 100644
--- a/src/handler/point.rs
+++ b/src/handler/point.rs
@@ -5,6 +5,7 @@ use axum::{
     Json,
 };
 use serde::{Deserialize, Serialize};
+use serde_with::rust::double_option;
 use sqlx::{QueryBuilder, Row};
 use std::collections::{HashMap, HashSet};
 use uuid::Uuid;
@@ -145,11 +146,16 @@ pub async fn get_point_history(
 #[derive(Deserialize, Validate)]
 pub struct UpdatePointReq {
     pub name: Option<String>,
-    pub description: Option<String>,
-    pub unit: Option<String>,
-    pub tag_id: Option<Uuid>,
-    pub equipment_id: Option<Uuid>,
-    pub signal_role: Option<String>,
+    #[serde(default, with = "double_option")]
+    pub description: Option<Option<String>>,
+    #[serde(default, with = "double_option")]
+    pub unit: Option<Option<String>>,
+    #[serde(default, with = "double_option")]
+    pub tag_id: Option<Option<Uuid>>,
+    #[serde(default, with = "double_option")]
+    pub equipment_id: Option<Option<Uuid>>,
+    #[serde(default, with = "double_option")]
+    pub signal_role: Option<Option<String>>,
 }
 
 /// Request payload for batch setting point tags.
@@ -187,7 +193,7 @@ pub async fn update_point(
     }
 
     // If tag_id is provided, ensure tag exists.
-    if let Some(tag_id) = payload.tag_id {
+    if let Some(Some(tag_id)) = payload.tag_id {
         let tag_exists = sqlx::query(r#"SELECT 1 FROM tag WHERE id = $1"#)
             .bind(tag_id)
             .fetch_optional(pool)
@@ -199,7 +205,7 @@ pub async fn update_point(
         }
     }
 
-    if let Some(equipment_id) = payload.equipment_id {
+    if let Some(Some(equipment_id)) = payload.equipment_id {
         let equipment_exists = sqlx::query(r#"SELECT 1 FROM equipment WHERE id = $1"#)
             .bind(equipment_id)
             .fetch_optional(pool)
@@ -220,29 +226,56 @@ pub async fn update_point(
         return Err(ApiErr::NotFound("Point not found".to_string(), None));
     }
 
-    let mut qb = QueryBuilder::new("UPDATE point SET ");
-    let mut sep = qb.separated(", ");
+    let mut qb: QueryBuilder<sqlx::Postgres> = QueryBuilder::new("UPDATE point SET ");
+    let mut wrote_field = false;
 
     if let Some(name) = &payload.name {
-        sep.push("name = ").push_bind(name);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("name = ").push_bind(name);
+        wrote_field = true;
     }
     if let Some(description) = &payload.description {
-        sep.push("description = ").push_bind(description);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("description = ").push_bind(description.as_deref());
+        wrote_field = true;
     }
     if let Some(unit) = &payload.unit {
-        sep.push("unit = ").push_bind(unit);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("unit = ").push_bind(unit.as_deref());
+        wrote_field = true;
     }
     if let Some(tag_id) = &payload.tag_id {
-        sep.push("tag_id = ").push_bind(tag_id);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("tag_id = ").push_bind(tag_id.as_ref());
+        wrote_field = true;
     }
     if let Some(equipment_id) = &payload.equipment_id {
-        sep.push("equipment_id = ").push_bind(equipment_id);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("equipment_id = ").push_bind(equipment_id.as_ref());
+        wrote_field = true;
     }
     if let Some(signal_role) = &payload.signal_role {
-        sep.push("signal_role = ").push_bind(signal_role);
+        if wrote_field {
+            qb.push(", ");
+        }
+        qb.push("signal_role = ").push_bind(signal_role.as_deref());
+        wrote_field = true;
     }
 
-    sep.push("updated_at = NOW()");
+    if wrote_field {
+        qb.push(", ");
+    }
+    qb.push("updated_at = NOW()");
 
     qb.push(" WHERE id = ").push_bind(point_id);
     qb.build().execute(pool).await?;