GraphQL Operations in React

Learn how to perform GraphQL operations and manage database permissions while building a complete todos application with Nhost and React

This part builds upon the previous parts by demonstrating how to perform GraphQL operations with proper database permissions. You’ll learn how to design database tables, configure user permissions, and implement complete CRUD operations through GraphQL queries and mutations in a real todos application.

This is Part 4 in the Full-Stack React Development with Nhost series. This part focuses on GraphQL operations, database management, and permission-based data access control in a production application.

Full-Stack React Development with Nhost

1. Create Project

Set up your Nhost project

2. Protected Routes

Route protection basics

3. User Authentication

Complete auth flow

4. GraphQL Operations

Current - CRUD operations with GraphQL

5. File Uploads

File upload and management

Prerequisites

• Complete the User Authentication part first
• The project from the previous part set up and running

What You’ll Build

By the end of this part, you’ll have:

• GraphQL queries and mutations for complete CRUD operations
• Database schema with proper relationships and constraints
• User permissions for secure data access control
• React components that interact with GraphQL endpoint

Step-by-Step Guide

1. Create the To-Dos Table

   First, we’ll perform the database changes to set up the todos table with proper schema and relationships to users.

   In your Nhost project dashboard:

   1. Navigate to Database
   2. Click on the SQL Editor

   Enter the following SQL:

   SQL

   CREATE TABLE public.todos (
     id uuid DEFAULT gen_random_uuid() NOT NULL,
     created_at timestamptz DEFAULT now() NOT NULL,
     updated_at timestamptz DEFAULT now() NOT NULL,
     title text NOT NULL,
     details text,
     completed bool DEFAULT false NOT NULL,
     user_id uuid NOT NULL,
     PRIMARY KEY (id),
     FOREIGN KEY (user_id) REFERENCES auth.users (id) ON UPDATE CASCADE ON DELETE CASCADE
   );
   
   
   CREATE OR REPLACE FUNCTION update_updated_at_column()
   RETURNS TRIGGER AS $$
   BEGIN
     NEW.updated_at = now();
     RETURN NEW;
   END;
   $$ language 'plpgsql';
   
   
   CREATE TRIGGER update_todos_updated_at
     BEFORE UPDATE ON public.todos
     FOR EACH ROW
     EXECUTE FUNCTION update_updated_at_column();
   
   

   Please make sure to enable Track this so that the new table todos is available through the auto-generated APIs

2. Set Up Permissions

   It’s now time to set permission rules for the table you just created. With the table todos selected, click on …, followed by Edit Permissions. You will set permissions for the user role and actions insert, select, update, and delete.

   Insert

   When inserting permissions we are only allowing users to set the title, details, and completed columns as the rest of the columns are set automatically by the backend. The user_id column is configured as a preset to the currently authenticated user’s ID using the X-Hasura-User-Id session variable. This ensures that each todo is associated with the user who created it.

   
3. Create the Todos Page Component

   Now let’s implement the React component that uses the database we just configured.

   src/pages/Todos.tsx

   import type { JSX } from "react";
   import { useCallback, useEffect, useId, useState } from "react";
   import { useAuth } from "../lib/nhost/AuthProvider";
   
   // The interfaces below define the structure of our data
   // They are not strictly necessary but help with type safety
   
   // Represents a single todo item
   interface Todo {
     id: string;
     title: string;
     details: string | null;
     completed: boolean;
     created_at: string;
     updated_at: string;
     user_id: string;
   }
   
   // This matches the GraphQL response structure for fetching todos
   // Can be used as a generic type on the request method
   interface GetTodos {
     todos: Todo[];
   }
   
   // This matches the GraphQL response structure for inserting a todo
   // Can be used as a generic type on the request method
   interface InsertTodo {
     insert_todos_one: Todo | null;
   }
   
   // This matches the GraphQL response structure for updating a todo
   // Can be used as a generic type on the request method
   interface UpdateTodo {
     update_todos_by_pk: Todo | null;
   }
   
   export default function Todos(): JSX.Element {
     const { nhost, session } = useAuth();
     const [todos, setTodos] = useState<Todo[]>([]);
     const [loading, setLoading] = useState(true);
     const [error, setError] = useState<string | null>(null);
     const [newTodoTitle, setNewTodoTitle] = useState("");
     const [newTodoDetails, setNewTodoDetails] = useState("");
     const [editingTodo, setEditingTodo] = useState<Todo | null>(null);
     const [showAddForm, setShowAddForm] = useState(false);
     const [expandedTodos, setExpandedTodos] = useState<Set<string>>(new Set());
   
     const titleId = useId();
     const detailsId = useId();
   
     const fetchTodos = useCallback(async () => {
       try {
         setLoading(true);
         // Make GraphQL request to fetch todos using Nhost client
         // The query automatically filters by user_id due to Hasura permissions
         const response = await nhost.graphql.request<GetTodos>({
           query: `
             query GetTodos {
               todos(order_by: { created_at: desc }) {
                 id
                 title
                 details
                 completed
                 created_at
                 updated_at
                 user_id
               }
             }
           `,
         });
   
         // Check for GraphQL errors in the response body
         if (response.body.errors) {
           throw new Error(
             response.body.errors[0]?.message || "Failed to fetch todos",
           );
         }
   
         // Extract todos from the GraphQL response data
         setTodos(response.body?.data?.todos || []);
         setError(null);
       } catch (err) {
         setError(err instanceof Error ? err.message : "Failed to fetch todos");
       } finally {
         setLoading(false);
       }
     }, [nhost.graphql]);
   
     const addTodo = async (e: React.FormEvent) => {
       e.preventDefault();
       if (!newTodoTitle.trim()) return;
   
       try {
         // Execute GraphQL mutation to insert a new todo
         // user_id is automatically set by Hasura based on JWT token
         const response = await nhost.graphql.request<InsertTodo>({
           query: `
             mutation InsertTodo($title: String!, $details: String) {
               insert_todos_one(object: { title: $title, details: $details }) {
                 id
                 title
                 details
                 completed
                 created_at
                 updated_at
                 user_id
               }
             }
           `,
           variables: {
             title: newTodoTitle.trim(),
             details: newTodoDetails.trim() || null,
           },
         });
   
         if (response.body.errors) {
           throw new Error(
             response.body.errors[0]?.message || "Failed to add todo",
           );
         }
   
         if (!response.body?.data?.insert_todos_one) {
           throw new Error("Failed to add todo");
         }
         setTodos([response.body?.data?.insert_todos_one, ...todos]);
         setNewTodoTitle("");
         setNewTodoDetails("");
         setShowAddForm(false);
         setError(null);
       } catch (err) {
         setError(err instanceof Error ? err.message : "Failed to add todo");
       }
     };
   
     const updateTodo = async (
       id: string,
       updates: Partial<Pick<Todo, "title" | "details" | "completed">>,
     ) => {
       try {
         // Execute GraphQL mutation to update an existing todo by primary key
         // Hasura permissions ensure users can only update their own todos
         const response = await nhost.graphql.request<UpdateTodo>({
           query: `
             mutation UpdateTodo($id: uuid!, $updates: todos_set_input!) {
               update_todos_by_pk(pk_columns: { id: $id }, _set: $updates) {
                 id
                 title
                 details
                 completed
                 created_at
                 updated_at
                 user_id
               }
             }
           `,
           variables: {
             id,
             updates,
           },
         });
   
         if (response.body.errors) {
           throw new Error(
             response.body.errors[0]?.message || "Failed to update todo",
           );
         }
   
         if (!response.body?.data?.update_todos_by_pk) {
           throw new Error("Failed to update todo");
         }
   
         const updatedTodo = response.body?.data?.update_todos_by_pk;
         if (updatedTodo) {
           setTodos(todos.map((todo) => (todo.id === id ? updatedTodo : todo)));
         }
         setEditingTodo(null);
         setError(null);
       } catch (err) {
         setError(err instanceof Error ? err.message : "Failed to update todo");
       }
     };
   
     const deleteTodo = async (id: string) => {
       if (!confirm("Are you sure you want to delete this todo?")) return;
   
       try {
         // Execute GraphQL mutation to delete a todo by primary key
         // Hasura permissions ensure users can only delete their own todos
         const response = await nhost.graphql.request({
           query: `
             mutation DeleteTodo($id: uuid!) {
               delete_todos_by_pk(id: $id) {
                 id
               }
             }
           `,
           variables: {
             id,
           },
         });
   
         if (response.body.errors) {
           throw new Error(
             response.body.errors[0]?.message || "Failed to delete todo",
           );
         }
   
         setTodos(todos.filter((todo) => todo.id !== id));
         setError(null);
       } catch (err) {
         setError(err instanceof Error ? err.message : "Failed to delete todo");
       }
     };
   
     const toggleComplete = async (todo: Todo) => {
       await updateTodo(todo.id, { completed: !todo.completed });
     };
   
     const saveEdit = async () => {
       if (!editingTodo) return;
       await updateTodo(editingTodo.id, {
         title: editingTodo.title,
         details: editingTodo.details,
       });
     };
   
     const toggleTodoExpansion = (todoId: string) => {
       const newExpanded = new Set(expandedTodos);
       if (newExpanded.has(todoId)) {
         newExpanded.delete(todoId);
       } else {
         newExpanded.add(todoId);
       }
       setExpandedTodos(newExpanded);
     };
   
     // Fetch todos when user session is available
     // The session contains the JWT token needed for GraphQL authentication
     useEffect(() => {
       if (session) {
         fetchTodos();
       }
     }, [session, fetchTodos]);
   
     if (!session) {
       return (
         <div className="auth-message">
           <p>Please sign in to view your todos.</p>
         </div>
       );
     }
   
     return (
       <div className="container">
         <header className="page-header">
           <h1 className="page-title">
             My Todos
             {!showAddForm && (
               <button
                 type="button"
                 onClick={() => setShowAddForm(true)}
                 className="add-todo-btn"
                 title="Add a new todo"
               >
                 +
               </button>
             )}
           </h1>
         </header>
   
         {error && (
           <div className="error-message">
             <strong>Error:</strong> {error}
           </div>
         )}
   
         {showAddForm && (
           <div className="todo-form-card">
             <form onSubmit={addTodo} className="todo-form">
               <h2 className="form-title">Add New Todo</h2>
               <div className="form-fields">
                 <div className="field-group">
                   <label htmlFor={titleId}>Title *</label>
                   <input
                     id={titleId}
                     type="text"
                     value={newTodoTitle}
                     onChange={(e) => setNewTodoTitle(e.target.value)}
                     placeholder="What needs to be done?"
                     required
                   />
                 </div>
                 <div className="field-group">
                   <label htmlFor={detailsId}>Details</label>
                   <textarea
                     id={detailsId}
                     value={newTodoDetails}
                     onChange={(e) => setNewTodoDetails(e.target.value)}
                     placeholder="Add some details (optional)..."
                     rows={3}
                   />
                 </div>
                 <div className="form-actions">
                   <button type="submit" className="btn btn-primary">
                     Add Todo
                   </button>
                   <button
                     type="button"
                     onClick={() => {
                       setShowAddForm(false);
                       setNewTodoTitle("");
                       setNewTodoDetails("");
                     }}
                     className="btn btn-secondary"
                   >
                     Cancel
                   </button>
                 </div>
               </div>
             </form>
           </div>
         )}
   
         {!showAddForm &&
           (loading ? (
             <div className="loading-container">
               <div className="loading-content">
                 <div className="spinner"></div>
                 <span className="loading-text">Loading todos...</span>
               </div>
             </div>
           ) : (
             <div className="todos-list">
               {todos.length === 0 ? (
                 <div className="empty-state">
                   <svg
                     className="empty-icon"
                     fill="none"
                     stroke="currentColor"
                     viewBox="0 0 24 24"
                     aria-hidden="true"
                   >
                     <path
                       strokeLinecap="round"
                       strokeLinejoin="round"
                       strokeWidth={1.5}
                       d="M9 5H7a2 2 0 00-2 2v10a2 2 0 002 2h8a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2"
                     />
                   </svg>
                   <h3 className="empty-title">No todos yet</h3>
                   <p className="empty-description">
                     Create your first todo to get started!
                   </p>
                 </div>
               ) : (
                 todos.map((todo) => (
                   <div
                     key={todo.id}
                     className={`todo-card ${todo.completed ? "completed" : ""}`}
                   >
                     {editingTodo?.id === todo.id ? (
                       <div className="todo-edit">
                         <div className="edit-fields">
                           <div className="field-group">
                             <label htmlFor={`${titleId}-edit`}>Title</label>
                             <input
                               id={`${titleId}-edit`}
                               type="text"
                               value={editingTodo.title}
                               onChange={(e) =>
                                 setEditingTodo({
                                   ...editingTodo,
                                   title: e.target.value,
                                 })
                               }
                             />
                           </div>
                           <div className="field-group">
                             <label htmlFor={`${detailsId}-edit`}>Details</label>
                             <textarea
                               id={`${detailsId}-edit`}
                               value={editingTodo.details || ""}
                               onChange={(e) =>
                                 setEditingTodo({
                                   ...editingTodo,
                                   details: e.target.value,
                                 })
                               }
                               rows={3}
                             />
                           </div>
                           <div className="edit-actions">
                             <button
                               type="button"
                               onClick={saveEdit}
                               className="btn btn-primary"
                             >
                               ✓ Save Changes
                             </button>
                             <button
                               type="button"
                               onClick={() => setEditingTodo(null)}
                               className="btn btn-cancel"
                             >
                               ✕ Cancel
                             </button>
                           </div>
                         </div>
                       </div>
                     ) : (
                       <div className="todo-content">
                         <div className="todo-header">
                           <button
                             type="button"
                             className={`todo-title-btn ${todo.completed ? "completed" : ""}`}
                             onClick={() => toggleTodoExpansion(todo.id)}
                           >
                             {todo.title}
                           </button>
                           <div className="todo-actions">
                             <button
                               type="button"
                               onClick={() => toggleComplete(todo)}
                               className="action-btn action-btn-complete"
                               title={
                                 todo.completed
                                   ? "Mark as incomplete"
                                   : "Mark as complete"
                               }
                             >
                               {todo.completed ? "↶" : "✓"}
                             </button>
                             <button
                               type="button"
                               onClick={() => setEditingTodo(todo)}
                               className="action-btn action-btn-edit"
                               title="Edit todo"
                             >
                               ✏️
                             </button>
                             <button
                               type="button"
                               onClick={() => deleteTodo(todo.id)}
                               className="action-btn action-btn-delete"
                               title="Delete todo"
                             >
                               🗑️
                             </button>
                           </div>
                         </div>
   
                         {expandedTodos.has(todo.id) && (
                           <div className="todo-details">
                             {todo.details && (
                               <div
                                 className={`todo-description ${todo.completed ? "completed" : ""}`}
                               >
                                 <p>{todo.details}</p>
                               </div>
                             )}
   
                             <div className="todo-meta">
                               <div className="meta-dates">
                                 <span className="meta-item">
                                   Created:{" "}
                                   {new Date(todo.created_at).toLocaleString()}
                                 </span>
                                 <span className="meta-item">
                                   Updated:{" "}
                                   {new Date(todo.updated_at).toLocaleString()}
                                 </span>
                               </div>
                               {todo.completed && (
                                 <div className="completion-badge">
                                   <svg
                                     className="completion-icon"
                                     fill="none"
                                     stroke="currentColor"
                                     viewBox="0 0 24 24"
                                     aria-hidden="true"
                                   >
                                     <path
                                       strokeLinecap="round"
                                       strokeLinejoin="round"
                                       strokeWidth={2}
                                       d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z"
                                     />
                                   </svg>
                                   <span>Completed</span>
                                 </div>
                               )}
                             </div>
                           </div>
                         )}
                       </div>
                     )}
                   </div>
                 ))
               )}
             </div>
           ))}
       </div>
     );
   }
   

4. Update App Routes

   Add the todos page to your application routing.

   src/App.tsx

   import {
     createBrowserRouter,
     createRoutesFromElements,
     Navigate,
     Outlet,
     Route,
     RouterProvider,
   } from "react-router-dom";
   import Navigation from "./components/Navigation";
   import ProtectedRoute from "./components/ProtectedRoute";
   import { AuthProvider } from "./lib/nhost/AuthProvider";
   import Home from "./pages/Home";
   import Profile from "./pages/Profile";
   import SignIn from "./pages/SignIn";
   import SignUp from "./pages/SignUp";
   import Todos from "./pages/Todos";
   import Verify from "./pages/Verify";
   
   // Root layout component to wrap all routes
   const RootLayout = () => {
     return (
       <>
         <Navigation />
         <div className="app-content">
           <Outlet />
         </div>
       </>
     );
   };
   
   // Create router with routes
   const router = createBrowserRouter(
     createRoutesFromElements(
       <Route element={<RootLayout />}>
         <Route index element={<Home />} />
         <Route path="signin" element={<SignIn />} />
         <Route path="signup" element={<SignUp />} />
         <Route path="verify" element={<Verify />} />
         <Route element={<ProtectedRoute />}>
           <Route path="profile" element={<Profile />} />
           <Route path="todos" element={<Todos />} />
         </Route>
         <Route path="*" element={<Navigate to="/" />} />
       </Route>,
     ),
   );
   
   function App() {
     return (
       <AuthProvider>
         <RouterProvider router={router} />
       </AuthProvider>
     );
   }
   
   export default App;
   

5. Update Navigation Links

   Add a link to the todos page in the navigation bar.

   src/components/Navigation.tsx

   import { Link, useNavigate } from "react-router-dom";
   import { useAuth } from "../lib/nhost/AuthProvider";
   
   export default function Navigation() {
     const { isAuthenticated, session, nhost } = useAuth();
     const navigate = useNavigate();
   
     const handleSignOut = async () => {
       try {
         if (session) {
           await nhost.auth.signOut({
             refreshToken: session.refreshToken,
           });
         }
         navigate("/");
       } catch (err: unknown) {
         const message = err instanceof Error ? err.message : String(err);
         console.error("Error signing out:", message);
       }
     };
   
     return (
       <nav className="navigation">
         <div className="nav-container">
           <Link to="/" className="nav-logo">
             Nhost React Demo
           </Link>
   
           <div className="nav-links">
             <Link to="/" className="nav-link">
               Home
             </Link>
   
             {isAuthenticated ? (
               <>
                 <Link to="/todos" className="nav-link">
                   Todos
                 </Link>
                 <Link to="/profile" className="nav-link">
                   Profile
                 </Link>
                 <button
                   type="button"
                   onClick={handleSignOut}
                   className="nav-link nav-button"
                 >
                   Sign Out
                 </button>
               </>
             ) : (
               <>
                 <Link to="/signin" className="nav-link">
                   Sign In
                 </Link>
                 <Link to="/signup" className="nav-link">
                   Sign Up
                 </Link>
               </>
             )}
           </div>
         </div>
       </nav>
     );
   }
   

6. Test Your Complete Application

   Run your application and test all the functionality:

   npm run dev
   

   Things to try out:

   1. Try signing in and out and see how the Todos page is only available when authenticated
   2. Create, view, edit, complete, and delete todos. See how the UI updates accordingly
   3. Open the application in another browser or incognito window, sign in with a different account and verify that you cannot see or modify todos from the first account

Key Features Implemented

Database Schema

Properly designed todos table with constraints, indexes, and automatic timestamp updates for optimal performance.

GraphQL API

Auto-generated GraphQL API with queries and mutations for full CRUD operations on todos.

Row-Level Security

Comprehensive permissions ensuring users can only access their own todos through all GraphQL operations.

CRUD Operations

Complete Create, Read, Update, Delete functionality with proper error handling and user feedback.

Rich Interface

Expandable todo items, inline editing, completion status, and detailed timestamps.