我应该使用什么来代替 useSelector 或 mapStateToProps？

Question

What should I use instead of useSelector or mapStateToProps ? Those run multiple times and change all values to the last one.

I have an e-commerce app, ProductDetails component contains product reviews and I map those to the ProductReview component to get user info that gets from user Id.

ProductDetails.js

import React, { useEffect } from "react";
import ProductReview from "../components/ProductReview";
import { useSelector, useDispatch } from 'react-redux';
import { getProductDetailsById } from "../Store/actions/productActions";

export default function ProductDetails(props) {
    const dispatch = useDispatch()
    const product = useSelector((state) => state.product)

  useEffect(() => {
    const { id } = props.match.params;
    const payload = {
      params: {
        id,
      },
    };
    dispatch(getProductDetailsById(payload));
    
  },[dispatch, props.match.params]);

  return (
    <div>
      {product.productDetails.reviews && 
        product.productDetails.reviews.map((item , index) =>    
        (
           <li key={item.userId}>
              <ProductReview key={item.userId} userId={item.userId} 
                             review={item.review}/>
           </li> )
               )}
        )}
</div>
  );
}

ProductReview.js

import React,{ useState, useEffect } from 'react';
import { getUSerById } from '../Store/actions/userAction';
import {useDispatch , useSelector} from 'react-redux';

export default function ProductReview(props) {
  const dispatch = useDispatch()
  const user = useSelector(state => state.user)
  
const {userId} = props;
  
  useEffect(() => {
    const payload = {
      params : {
        userId
      }
    }
    dispatch(getUSerById(payload))  
  },[userId]);

    
 return (
    <div>
        {user && user.user.firstName} : {props.review}
    </div>
  )
}

this part of the code runs multiple times and changes all user info values (user first name) to the last one. **All product reviews firstName s change to the last one ** all same name

  const user = useSelector(state => state.user)

Is there any way to get rid of this?? It runs currently when using Axios in the ProductReview component with useState() , but I want to use redux.

userReducer.js

import { userConstants } from "../actions/Types";

const initState = {
  user: {},
  loading: false,
  error: null
};

export default (state = initState, action) => {
  console.log(action.payload)
  switch(action.type){
    case userConstants.GET_USER_BY_ID_SUCCESS:
      return state = {
        ...state,
        user : action.payload.user,
        loading: false,
        error: null
      }
    case userConstants.GET_USER_BY_ID_FAILURE:
      return state = {
        state,
        error: action.payload.error
      }  
    default:
      return state
  }
}

Answer 1

From what I understand in the comments you need to store all users in your redux store in some way. For example you could do something like the following:

1. Change initState with:

    const initState = { users: {}, loading: false, error: null };

2. Change GET_USER_BY_ID_SUCCESS reducer with (please pay attention that I'm using user.id , but maybe your id is stored in some other property):

    case userConstants.GET_USER_BY_ID_SUCCESS: return state = { ...state, users: { ...state.users, [action.payload.user.id]: action.payload.user }, loading: false, error: null }

3. Change useSelector with:

    const users = useSelector(state => state.users)

4. Add:

    const user = users[props.userId]

In this way you should have the correct user. If I miss something please tell me.