Query Results

Query Results is an important part of working effectively with Redux. This lesson explains what query results means, how it works, and how to apply it with practical examples you can reuse.

Query Results Overview

Query Results lets you work with Redux in a way that stays clear, repeatable, and easy to scale. Instead of ad-hoc steps, you follow a pattern that other developers recognise immediately.

The key is to keep query results focused and predictable. Start from the minimal example here, then add only the complexity your situation actually needs.

import { createApi, fetchBaseQuery } from '@reduxjs/toolkit/query/react';

export const api = createApi({
  reducerPath: 'api',
  baseQuery: fetchBaseQuery({ baseUrl: '/api' }),
  endpoints: (builder) => ({
    getUsers: builder.query({ query: () => 'users' }),
    addUser: builder.mutation({
      query: (body) => ({ url: 'users', method: 'POST', body }),
    }),
  }),
});

export const { useGetUsersQuery, useAddUserMutation } = api;

RTK Query handles data fetching, caching, and auto-generated React hooks for you.

Query Results Example

const slice = createSlice({ name, initialState, reducers });
const store = configureStore({ reducer: { key: slice.reducer } });
// dispatch(slice.actions.something())

Start from a minimal Query Results example and grow it only as needed.
Keep things explicit so Query Results behaves the same for everyone on the team.
Name things clearly so teammates understand your Query Results at a glance.
Verify Query Results works as expected before relying on it in important work.

Redux Cheatsheet

Quick Redux Toolkit reference related to query results.

Concept	Example	Purpose
Store	`configureStore({ reducer })`	Hold app state
Slice	`createSlice({ name, reducers })`	State + actions together
Read state	`useSelector((s) => s.x)`	Get data in components
Dispatch	`useDispatch()`	Send actions
Async	`createAsyncThunk(...)`	Handle side effects
Data fetching	`createApi(...)`	RTK Query endpoints
Derived data	`createSelector(...)`	Memoized computations

How Query Results Works in Redux

Query Results follows Redux's predictable data flow: components dispatch actions, reducers compute the next state from the previous state and the action, and subscribed components re-render.

RTK Query handles data fetching, caching, and auto-generated React hooks for you.

State lives in a single, read-only store.
Actions are the only way to describe a change.
Reducers are pure functions that return the next state.
Redux Toolkit removes most boilerplate with slices and thunks.

Practical Guidance for Query Results

In modern apps, query results should use Redux Toolkit rather than hand-written Redux. Keep state minimal, colocate logic in slices, and use RTK Query for server data.

Concern	Recommendation
Boilerplate	Use Redux Toolkit (createSlice)
Server data	Prefer RTK Query over manual thunks
Performance	Memoize selectors with createSelector
Types	Use typed useAppSelector/useAppDispatch hooks

Common Mistakes

Copying query results commands or snippets without understanding what each part does.
Skipping edge cases and error handling when using query results.
Not verifying the result of query results before moving on.
Over-complicating query results before you actually need the extra flexibility.

Key Takeaways

Query Results is a core part of working effectively with Redux.
Start small and keep query results focused on a single goal.
Apply consistent patterns so query results scales across your project.
Practise and document query results to keep your workflow maintainable.

Pro Tip

When you get stuck on query results, reduce it to the smallest example first — most Redux problems become obvious once the noise is gone.