조합 이름 변경 에러 수정

src/repositories/myRepository.js

 import pool from '../db.js';
 
 const myRepository = {
+  async checkUserExists(userId) {
+    const query = `
+      SELECT 1
+      FROM users
+      WHERE id = $1
+    `;
+    const values = [userId];
+
+    const { rows } = await pool.query(query, values);
+    return rows.length > 0;
+  },
+
+  async getCombinationById(combinationId) {
+    const query = `
+      SELECT id, name, owner_id AS "userId"
+      FROM combinations
+      WHERE id = $1
+    `;
+    const values = [combinationId];
+
+    const { rows } = await pool.query(query, values);
+    return rows.length > 0 ? rows[0] : null;
+  },
+
   async getCombinationsByUserId(userId) {
     const query = `
       SELECT id, name 
@@ -49,7 +73,7 @@ const myRepository = {
   async updateCombinationName(combinationId, newName) {
     const query = `
       UPDATE combinations
-      SET name = $1, updated_at = NOW()
+      SET name = $1
       WHERE id = $2
     `;
     const values = [newName, combinationId];