public with sharing class getRecordDataController {
    //@AuraEnabled is annotation enables LWC to access below apex method
    //(cacheable=true) is for caching the data on client side storage without
      //waiting for server trips. Which imporves the performance
    @AuraEnabled(cacheable=true)
     public static List<Case> getCases() {
     return [SELECT Id,CaseNumber, Subject, Status, dotsquaremukesh__reason_for_closure__c FROM Case WHERE Status = 'New' AND dotsquaremukesh__reason_for_closure__c = ''];
     }

     @AuraEnabled
     public static List<Case>  updateStatus(List<String> caseIds){
         List<Case> updateCase  = new List<Case>();
        List<Case> caseList = [SELECT Id,CaseNumber, Subject, Status FROM Case Where Id IN: caseIds];
        for(Case c : caseList){
            c.Status = 'Closed';
            updateCase.add(c);
        } 

        if(updateCase.size() > 0)
          update updateCase;

        return updateCase;
     }

   }

<template>

    Case Close List
    <lightning-card title="Inline Edit With Lightning Datatable in LWC">
        <lightning-button onclick={updateCaseStatus} label="Close Selected Case"></lightning-button>
        <template if:true={cases.data}>
            <lightning-datatable key-field="Id"
                                 data={cases.data}
                                 columns={columns}
                                 onsave={handleSave}
                                 draft-values={saveDraftValues}                                                            
                                 onrowselection={getSelectedName}>
            </lightning-datatable>
        </template>
    </lightning-card>
</template>

import { LightningElement, wire, track } from 'lwc';
import getCases from '@salesforce/apex/getRecordDataController.getCases';
import updateCaseStatus from '@salesforce/apex/getRecordDataController.updateStatus';
import { updateRecord } from 'lightning/uiRecordApi';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import { refreshApex } from '@salesforce/apex';
// datatable columns
const columns = [
    {
        label: 'CaseNumber',
        fieldName: 'CaseNumber',
        type: 'text',
    }, {
        label: 'Subject',
        fieldName: 'Subject',
        type: 'text',
        editable: true,
    }, {
        label: 'Status',
        fieldName: 'Status',
        type: 'text',
        editable: true,
    }, {
        label: 'Reason for closure',
        fieldName: 'dotsquaremukesh__reason_for_closure__c',
        type: 'text',
        editable: true
    }
];
export default class CaseClose extends LightningElement {
    columns = columns;
    @track cases;
    @track error;
    saveDraftValues = [];
    selectedCase = [];

    @wire(getCases)
    cons(result) {
        this.cases = result;
        if (result.error) {
            this.cases = undefined;
        }
    };
    getSelectedName(event) {
     const selectedRows = event.detail.selectedRows;
     // Display that fieldName of the selected rows
     for (let i = 0; i < selectedRows.length; i++){
         //console.log("You selected: " + selectedRows[i].CaseNumber);
         this.selectedCase.push(selectedRows[i].Id);
     }
 }
   /* handleSave(event) {
        this.saveDraftValues = event.detail.draftValues;
        const recordInputs = this.saveDraftValues.slice().map(draft => {
            const fields = Object.assign({}, draft);
            return { fields };
        });
        // Updateing the records using the UiRecordAPi
        const promises = recordInputs.map(recordInput => updateRecord(recordInput));
        Promise.all(promises).then(res => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Success',
                    message: 'Records Updated Successfully!!',
                    variant: 'success'
                })
            );
            this.saveDraftValues = [];
            return this.refresh();
        }).catch(error => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Error',
                    message: 'An Error Occured!!',
                    variant: 'error'
                })
            );
        }).finally(() => {
            this.saveDraftValues = [];
        });
    }*/

    updateCaseStatus(){
           console.log('selectedCase-- >>> '+this.selectedCase);
           updateCaseStatus({ caseIds: this.selectedCase })
           .then(result => {
            console.log('OK RESULT==>>> '+JSON.stringify(result));
           // console.log('KO ERRRO==>>> '+this.error);
               this.cases = result;
               this.error = undefined;
           })
           .catch(error => {
               this.error = error;
               this.cases = undefined;
           })
           
        }
    

    }