public class AccountTriggerHelper {
    public static void validateDeceasedAccounts(List<Account> newAccounts, Map<Id, Account> oldMap) {
        Set<Id> accIdSet = new Set<Id>();
        Map<Id, Case> casesMap = new Map<Id, Case>();

        for (Account acc : newAccounts) {
            Account oldAcc = oldMap.get(acc.Id);

            if (acc.Status__c == 'Deceased' && (
                    acc.DOB__c != oldAcc.DOB__c ||
                    acc.DOD__c != oldAcc.DOD__c ||
                    acc.Status__c != oldAcc.Status__c
                )) {
                if (acc.DOB__c == null || acc.DOD__c == null || acc.DOD__c <= acc.DOB__c) {
                    acc.addError('Please ensure that Date of Birth is populated, Date of Death is greater than Date of Birth, and Status is set to Deceased.');
                } else {
                    accIdSet.add(acc.Id);
                }
            }
        }

        if (!accIdSet.isEmpty()) {
            for (Case c : [SELECT Id, AccountId FROM Case WHERE AccountId IN :accIdSet AND Status != 'Closed']) {
                casesMap.put(c.AccountId, c);
            }
        }

        for (Account acc : newAccounts) {
            if (acc.Status__c == 'Deceased' && casesMap.containsKey(acc.Id)) {
                acc.addError('Please close all related cases before marking the status as Deceased.');
            }
        }
    }
}

trigger AccountTrigger on Account (before update) {
    for (Account acc : Trigger.new) {
        if (acc.Status__c == 'Deceased' && (acc.DOB__c == null || acc.DOD__c == null || acc.DOD__c <= acc.DOB__c)) {
            acc.addError('Please ensure that Date of Birth is populated, Date of Death is greater than Date of Birth, and Status is set to Deceased.');
        } else if (acc.Status__c == 'Deceased') {
            List<Case> relatedCases = [SELECT Id FROM Case WHERE AccountId = :acc.Id AND IsClosed = false];
            if (!relatedCases.isEmpty()) {
                acc.addError('Please close all related cases before marking the status as Deceased.');
            }
        }
    }
}

<!--Use template if:true to display/hide popup based on isModalOpen value--> 
   <template if:true={isModalOpen}>
    <!-- Modal/Popup Box LWC starts here -->
    <section role="dialog" tabindex="-1" aria-labelledby="modal-heading-01" aria-modal="true" aria-describedby="modal-content-id-1" class="slds-modal slds-fade-in-open">
        <div class="slds-modal__container">
            <!-- Modal/Popup Box LWC header here -->
            <header class="slds-modal__header">
                <button class="slds-button slds-button_icon slds-modal__close slds-button_icon-inverse" title="Close" onclick={closeModal}>
                    <lightning-icon icon-name="utility:close"
                        alternative-text="close"
                        variant="inverse"
                        size="small" ></lightning-icon>
                    <span class="slds-assistive-text">Close</span>
                </button>
                <h2 id="modal-heading-01" class="slds-text-heading_medium slds-hyphenate">Guest User Registration</h2>
            </header>
            <div class="slds-modal__content slds-p-around_medium" id="modal-content-id-1">
                <form class="form-fields">
                    <div class="form-grid">
                        <div class="form-col-1">
                            <lightning-input type="text" label="First Name" placeholder="Enter your first name" onchange={handleFirstNameChange}></lightning-input>
                            <lightning-input type="text" label="Last Name" placeholder="Enter your last name" onchange={handleLastNameChange}></lightning-input>
                            <lightning-input type="email" label="Email" placeholder="Enter your email" onchange={handleEmailChange}></lightning-input>
                        </div>
                        <div class="form-col-2">
                            <lightning-input type="tel" label="Phone Number" placeholder="Enter your phone number" onchange={handlePhoneChange}></lightning-input>
                         <!--  <lightning-input type="text" label="Company Name" placeholder="Enter your company name" onchange={handleCompanyNameChange}></lightning-input> --> 
                            <lightning-input type="date" label="Birthdate" placeholder="Enter your birthdate" onchange={handleBirthdateChange}></lightning-input> 
                        </div>
                    </div>
                </form>
            </div>

                <footer class="slds-modal__footer">
                    <button class="slds-button slds-button_neutral" onclick={closeModal} title="Cancel">Cancel</button>
                    <button class="slds-button slds-button_brand" onclick={handleSave} title="Save">Save</button>
                </footer>
            </div>
        </section>
        <div class="slds-backdrop slds-backdrop_open"></div>
    </template>

import { LightningElement,track } from 'lwc';
import { createRecord } from 'lightning/uiRecordApi';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import CONTACT_OBJECT from '@salesforce/schema/Contact';
import { NavigationMixin } from 'lightning/navigation';

export default class NewHomePage extends LightningElement {
    @track firstName = '';
    @track lastName = '';
    @track email = '';
    @track phone = '';
    @track companyname = '';
    @track birthdate = '';
    @track isModalOpen = false;

    handleFirstNameChange(event) {
        this.firstName = event.target.value;
    }

    handleLastNameChange(event) {
        this.lastName = event.target.value;
    }

    handleEmailChange(event) {
        this.email = event.target.value;
    }

    handlePhoneChange(event) {
        this.phone = event.target.value;
    }

    handleBirthdateChange(event) {
        this.birthdate = event.target.value;
    }

    handleSave() {
        const fields = {
            FirstName: this.firstName,
            LastName: this.lastName,
            Email: this.email,
            Birthdate : this.birthdate,
            Phone: this.phone
        };

        const recordInput = { apiName: CONTACT_OBJECT.objectApiName, fields };

        createRecord(recordInput)
            .then(() => {
                this.dispatchEvent(
                    new ShowToastEvent({
                        title: 'Success',
                        message: 'Contact created',
                        variant: 'success'
                    })
                );
                this.isModalOpen = false;
                this.firstName = '';
                this.lastName = '';
                this.email = '';
                this.birthdate = '';
                this.phone = '';

                this[NavigationMixin.Navigate]({
                    type: 'standard__webComponent',
                    attributes: {
                        webComponentName: 'c__questionFormPage',  // questionFormPage is lwc component
                    },
                    state: {
                        c__recordId: contact.id
                    }
                });
            })

            .catch(error => {
                this.dispatchEvent(
                    new ShowToastEvent({
                        title: 'Error creating contact',
                        message: error.body.message,
                        variant: 'error'
                    })
                );
            });

    }
    

    openModal() {
        this.isModalOpen = true;
    }
    closeModal() {
        this.isModalOpen = false;
    }
}

HTML

<lightning-button label="Save as Draft" variant="success" title="Save as Draft" onclick={handleDraft} class="slds-m-left_x-small" disabled={lockedToEdit}></lightning-button>
                        <lightning-button label="Submit" variant="brand" title="Submit" onclick={handleConfirmation} class="slds-m-left_x-small" disabled={lockedToEdit}></lightning-button>

JS

 submittedFlag = false;
 dayPassedFlag = false;

get lockedToEdit() {
        return this.submittedFlag || this.headView || this.dayPassedFlag;
    }
 //lasttwoweek condition
  if (last2Week.isoWeekday() == 7) {
            last2Week.subtract(1, 'weeks').startOf('isoWeek');
        } else {
            las2Week.subtract(1, 'weeks').startOf('isoWeek');
        }

 if (!this.headView && typeof this.existingFormcontinuation === 'undefined') {
            if (last2Week.isAfter(startDate)) {
                this.spinnerFlag = false;
                this.dispatchEvent(
                    new ShowToastEvent({
                        title: 'Error!!',
                        message: 'You can only fill the form for previous and current week!',
                        variant: 'error'
                    })
                );
                return this.changeDate();
            }
        } else if (!this.headView && typeof this.existingFormcontinuation === 'object') {
            if (last2Week.isAfter(startDate)) {
                this.dayPassedFlag = true;
            } else {
                this.dayPassedFlag = false;
            }
        }else {
            this.dayPassedFlag = false;
        }

List<CaseShare> csShareList = new List<CaseShare>();
for(case cs:trigger.new){
if(cs.Employee_Manager__c!=Null){
CaseShare csShare = new CaseShare();
// Give Read write access to that user for this particular case record.
csShare.CaseAccessLevel = 'Read';
// Assign case Id of case record.
csShare.CaseId = cs.id;
// Assign user id to grant read write access to this particular case record.
csShare.UserOrGroupId = cs.Employee_Manager__c;
csShare.RowCause='Manual';
csShareList.add( csShare );
}
}
insert csShareList;

trigger CaseAssignmentRuleTrigger on Case (before insert,before update) {
    //Fetching the assignment rules on case
    AssignmentRule AR = new AssignmentRule();
    AR = [select id from AssignmentRule where SobjectType = 'Case' and Active = true limit 1];
    
    //Creating the DMLOptions for "Assign using active assignment rules" checkbox
    Database.DMLOptions dmlOpts = new Database.DMLOptions();
    dmlOpts.assignmentRuleHeader.assignmentRuleId= AR.id;
    
    Case newCase = new Case(Status = 'New') ;
    //Setting the DMLOption on Case instance
    newCase.setOptions(dmlOpts);
    insert newCase ;
}

Apex method

  @AuraEnabled(cacheable=true)
    public static User userData (String Ids){
        try {
            return [select id,Timesheet_Restriction_Bypass__c from user where Id =:Ids];
        } catch (Exception e) {
            throw new AuraHandledException(e.getMessage());
        }
    }

JS

import userData from '@salesforce/apex/FormController.userData';
import Id from '@salesforce/user/Id';
import Timesheet_Restriction_Bypass__c from '@salesforce/schema/User.Timesheet_Restriction_Bypass__c';
const fields=[Timesheet_Restriction_Bypass__c];

export default class Form extends LightningElement {
   userId = Id;
    userBypass;
    @track error;

    @wire(userData, { Ids: '0057h000004mseIAAQ' })
    userDetails({ error, data }) {
        console.log('~~data -- ', data);
        if (data) {
            console.log('d1');
            if (data.Timesheet_Restriction_Bypass__c ) {
                console.log('wwww'+data.Timesheet_Restriction_Bypass__c);
                this.userBypass = data.Timesheet_Restriction_Bypass__c;
            }
        }else if (error) {
            console.log('e2'+this.error);
            this.error = error;
            console.log('e3'+this.error);
        } 
    }
  if(this.userBypass == true)
        {
            console.log('inside worked'+this.userBypass);
        if (last2Week.isoWeekday() == 7) {
            last2Week.subtract(1, 'weeks').startOf('isoWeek');
        } else {
            last2Week.subtract(1, 'weeks').startOf('isoWeek');
        }
    }
}

trigger AccountTrigger on Account (before update) {
    for (Account acc : Trigger.new) {
        if (acc.Status__c == 'Deceased' && (acc.DOB__c == null || acc.DOD__c == null || acc.DOD__c <= acc.DOB__c)) {
            acc.addError('Please ensure that Date of Birth is populated, Date of Death is greater than Date of Birth, and Status is set to Deceased.');
        } else if (acc.Status__c == 'Deceased') {
            List<Case> relatedCases = [SELECT Id FROM Case WHERE AccountId = :acc.Id AND IsClosed = false];
            if (!relatedCases.isEmpty()) {
                acc.addError('Please close all related cases before marking the status as Deceased.');
            }
        }
    }
}

List<CaseShare> csShareList = new List<CaseShare>();
for(case cs:trigger.new){
if(cs.Employee_Manager__c!=Null){
CaseShare csShare = new CaseShare();
// Give Read write access to that user for this particular case record.
csShare.CaseAccessLevel = 'Read';
// Assign case Id of case record.
csShare.CaseId = cs.id;
// Assign user id to grant read write access to this particular case record.
csShare.UserOrGroupId = cs.Employee_Manager__c;
csShare.RowCause='Manual';
csShareList.add( csShare );
}
}
insert csShareList;

trigger CaseAssignmentRuleTrigger on Case (before insert,before update) {
    //Fetching the assignment rules on case
    AssignmentRule AR = new AssignmentRule();
    AR = [select id from AssignmentRule where SobjectType = 'Case' and Active = true limit 1];
    
    //Creating the DMLOptions for "Assign using active assignment rules" checkbox
    Database.DMLOptions dmlOpts = new Database.DMLOptions();
    dmlOpts.assignmentRuleHeader.assignmentRuleId= AR.id;
    
    Case newCase = new Case(Status = 'New') ;
    //Setting the DMLOption on Case instance
    newCase.setOptions(dmlOpts);
    insert newCase ;
}

accountForm.html

<template>
    <div class="slds-grid slds-gutters">
        <div class="slds-col">
            <span>
                <lightning-input type="Currency" label="AnnualRevenue Start" value={revenueStart} name="AVStart"
                    onchange={handleChange} placeholder="Enter Value"></lightning-input>
            </span>
        </div>
        <div class="slds-col">
            <span>
                <lightning-input type="Currency" label="AnnualRevenue End" value={revenueEnd} name="AVEnd"
                    onchange={handleChange} placeholder="Enter Value"> </lightning-input>
            </span>
        </div>
        <div class="slds-col">
            <span>
                <template if:true={typeValues.data}>
                    <lightning-combobox name="Type" label="Type" value={value} options={typeValues.data.values}
                        onchange={handleChange} placeholder="Select Type">
                    </lightning-combobox>
                </template>
            </span>
        </div>
        <div class="slds-col">
            <span>
                <template if:true={ratingValues.data}>
                    <lightning-combobox name="Rating" label="Rating" value={value} options={ratingValues.data.values}
                        onchange={handleChange} placeholder="Select Rating">
                    </lightning-combobox>
                </template>
            </span>
        </div>
        <div class="slds-col">
            <span>
                <template if:true={industryValues.data}>
                    <lightning-combobox name="Industry" label="Industry" value={value}
                        options={industryValues.data.values} onchange={handleChange} placeholder="Select Industry">
                    </lightning-combobox>
                </template>
            </span>
        </div>
    </div>

    <lightning-button type="submit" variant="brand" label="Show Accounts" onclick={handleClick}></lightning-button>

    <template if:true={showSearchtable}>
        <lightning-datatable key-field="Id" data={accounts} columns={columns} onsave={handleSave}
            draft-values={draftValues} sorted-by={sortBy} sorted-direction={sortDirection} onsort={doSorting}
            hide-checkbox-column="true"></lightning-datatable>
    </template>
    
    <template if:true={showSearchComponent}>
        <p>No data to display</p>
    </template>

    <template if:true={loading}>
        <div class="slds-spinner_container">
            <lightning-spinner alternative-text="Loading" variant="brand" size="medium">
            </lightning-spinner>
        </div>
    </template>
    <div class="slds-m-around_medium">
        <p class="slds-m-vertical_medium content">
            Displaying {startingRecord} to {endingRecord} of {totalRecountCount} records.
            Page {page} of {totalPage}. </p>
        <c-paginator onprevious={previousHandler} onnext={nextHandler}></c-paginator>
    </div>
</template>

accountForm.js

import { LightningElement, wire, track, api } from 'lwc';

import { getPicklistValues } from 'lightning/uiObjectInfoApi';
import Type from '@salesforce/schema/Account.Type';
import Rating from '@salesforce/schema/Account.Rating';
import AnnualRevenue from '@salesforce/schema/Account.AnnualRevenue';
import ChangeRating__c from '@salesforce/schema/Account.ChangeRating__c';

import { getObjectInfo } from 'lightning/uiObjectInfoApi';
import ACCOUNT_OBJECT from '@salesforce/schema/Account';
import Industry from '@salesforce/schema/Account.Industry';

import getAccountList from '@salesforce/apex/AccountForm.getAccountList';



import { updateRecord } from 'lightning/uiRecordApi';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';


const columns = [
  { label: 'Account Name', fieldName: 'AccName', type: 'url', sortable: "true", typeAttributes: { label: { fieldName: 'Name' } } },
  { label: 'AnnualRevenue', fieldName: 'AnnualRevenue', type: 'currency', editable: true, sortable: "true" },

  { label: 'Industry', fieldName: 'Industry', editable: true, sortable: "true" },
  { label: 'Type', fieldName: 'Type', editable: true, sortable: "true" },
  { label: 'Rating', fieldName: 'Rating', type: 'picklist', editable: true, sortable: "true" },
  { label: 'Website', fieldName: 'Website', type: 'url', editable: true, sortable: "true" },
  { label: 'ChangeRating', fieldName: 'ChangeRating__c', type: 'number', editable: true, sortable: "true" }
];

let i = 0;
export default class AccountForm extends LightningElement {

  @track page = 1;
  @track items = [];
  @track columns;
  @track startingRecord = 1;
  @track endingRecord = 0;
  @track pageSize = 10;
  @track totalRecountCount = 0;
  @track totalPage = 0;

  @track accounts = [];
  @track showSearchComponent = false;
  @track showSearchtable;
  @track revenueStart;
  @track revenueEnd;
  @track loading = false;
  @track sortBy;
  @track sortDirection;

  @api recordId;
  columns = columns;
  draftValues = [];

  @wire(getObjectInfo, { objectApiName: ACCOUNT_OBJECT })
  accountInfo;
  nameVal;
  typeVal;
  industryVal;

  @wire(getPicklistValues, {
    recordTypeId: '$accountInfo.data.defaultRecordTypeId',
    fieldApiName: Type

  })
  typeValues;

  @wire(getPicklistValues, { recordTypeId: '$accountInfo.data.defaultRecordTypeId', fieldApiName: Rating })
  ratingValues;

  @wire(getPicklistValues, { recordTypeId: '$accountInfo.data.defaultRecordTypeId', fieldApiName: Industry })
  industryValues;


  handleChange(event) {
    var fieldname = event.target.label;
    if (fieldname == 'Rating') {
      this.nameVal = event.target.value;
    }
    else if (fieldname == 'Type') {
      this.typeVal = event.target.value;
    } else if (fieldname == 'Industry') {
      this.industryVal = event.target.value;
    }
    else if (fieldname == 'AnnualRevenue Start') {
      this.revenueStart = event.target.value;
    }
    else if (fieldname == 'AnnualRevenue End') {
      this.revenueEnd = event.target.value;
    }
  }

  handleClick() {
    this.showSearchComponent = true;
    this.loading = true;
    console.log('AnnualRevenueStart --> ', this.revenueStart);
    console.log('Anuual end --> ', this.revenueEnd);
    if (this.revenueEnd != null && this.revenueEnd != '' && this.revenueStart != null && this.revenueStart != '' && this.revenueEnd < this.revenueStart) {
      console.log('this.revenueEnd' + this.revenueEnd);
      this.loading = false;
      console.log('Alert message');
      const toastEvt = new ShowToastEvent({
        title: 'Error',
        message: 'AnnualRevenueEnd should not be lesser than AnnualRevenueStart',
        variant: 'error',

      });
      this.dispatchEvent(toastEvt);
    }
    else {
      getAccountList({ type: this.typeVal, rating: this.nameVal, industry: this.industryVal, AnnualRevenueStart: this.revenueStart, AnnualRevenueEnd: this.revenueEnd })
        .then(results => {
          if (results != null) {
            let tempAccList = [];
            results.forEach((result) => {
              let tempAccRec = Object.assign({}, result);
              tempAccRec.AccName = '/' + tempAccRec.Id;
              tempAccList.push(tempAccRec);
              this.showSearchComponent = false;
              this.showSearchtable = true;
              this.accounts = tempAccList;
            });
            if (accounts) {
              this.items = accounts;
              this.totalRecountCount = accounts.length;
              this.totalPage = Math.ceil(this.totalRecountCount / this.pageSize);
              this.accounts = this.items.slice(0, this.pageSize);
              this.endingRecord = this.pageSize;
              this.columns = columns;

              this.error = undefined;
            } else if (error) {
              this.error = error;
              this.accounts = undefined;
            }
          }
          else {
            this.showSearchtable = false;
            this.showSearchComponent = true;
          }
          this.loading = false;
        })
        .catch(error => {
          console.log('error' + error);
          this.loading = false;
        })
    }
  }

  handleSave(event) {
    const recordInputs = event.detail.draftValues.slice().map(draft => {
      const fields = Object.assign({}, draft);
      return { fields };
    });

    const promises = recordInputs.map(recordInput => updateRecord(recordInput));
    Promise.all(promises).then(accounts => {
      this.dispatchEvent(
        new ShowToastEvent({
          title: 'Success',
          message: 'Accounts updated',
          variant: 'success'
        })
      );
      // Clear all draft values
      this.draftValues = [];

      // Display fresh data in the 
      this.handleClick();

    }).catch(error => {
      // Handle error
    });
  }

  doSorting(event) {
    this.sortBy = event.detail.fieldName;
    this.sortDirection = event.detail.sortDirection;
    this.sortData(this.sortBy, this.sortDirection);
  }

  sortData(fieldname, direction) {
    let parseData = JSON.parse(JSON.stringify(this.accounts));

    let keyValue = (a) => {
      return a[fieldname];
    };

    let isReverse = direction === 'asc' ? 1 : -1;

    parseData.sort((x, y) => {
      x = keyValue(x) ? keyValue(x) : '';
      y = keyValue(y) ? keyValue(y) : '';

      return isReverse * ((x > y) - (y > x));
    });
    this.accounts = parseData;
  }

  previousHandler() {
    if (this.page > 1) {
      this.page = this.page - 1;
      this.displayRecordPerPage(this.page);
    }
  }
  nextHandler() {
    if ((this.page < this.totalPage) && this.page !== this.totalPage) {
      this.page = this.page + 1;
      this.displayRecordPerPage(this.page);
    }
  }
  displayRecordPerPage(page) {
    this.startingRecord = ((page - 1) * this.pageSize);
    this.endingRecord = (this.pageSize * page);
    this.endingRecord = (this.endingRecord > this.totalRecountCount)
      ? this.totalRecountCount : this.endingRecord;
    this.accounts = this.items.slice(this.startingRecord, this.endingRecord);
    this.startingRecord = this.startingRecord + 1;
  }
}

AccountForm.cls

public with sharing class AccountForm {
    @AuraEnabled
    public static List<Account>  getAccountList(String type,String rating,String industry,String AnnualRevenueStart,String AnnualRevenueEnd){
        System.debug('AnnualRevenueStart='+AnnualRevenueStart);
        System.debug('AnnualRevenueEnd='+AnnualRevenueEnd);
        String accQuery = 'SELECT Id,Name,Website,Type,Rating,AnnualRevenue,Industry,ChangeRating__c FROM Account';                     
        String whereClause  = '';
        String Query1;
        Integer arStart;
        if(String.isNotEmpty(AnnualRevenueStart)){
            arStart = Integer.valueOf(AnnualRevenueStart);
        }
        Integer arEnd;
        if(String.isNotEmpty(AnnualRevenueEnd)){
            arEnd = Integer.valueOf(AnnualRevenueEnd);
        }
        if(arStart!=Null){
            whereClause=whereClause+' where AnnualRevenue>=:arStart';
        }
        if(arEnd!=Null){
            if(String.isEmpty(whereClause)){
                whereClause=whereClause+' WHERE AnnualRevenue<=:arEnd';
            }
            else 
            {
                whereClause=whereClause+' AND AnnualRevenue<=:arEnd';
            }
        }
        if(String.isNotEmpty(type)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Type = :type';
            }else{
                whereClause =whereClause + ' AND Type = :type';
            }
            
        }
        if(String.isNotEmpty(rating)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Rating = :rating';
            }else{
                whereClause =whereClause + ' AND Rating = :rating';
            }
        } 
        if(String.isNotEmpty(industry)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Industry = :industry';
            }else{
                whereClause =whereClause + ' AND Industry = :industry';
            }
            
        } 
        String finalquery = accQuery+whereClause;
        System.debug('finalquery='+finalquery);
        
        List<Account> acclist=Database.query(finalquery);
        if(acclist.size()>0){
            return acclist;
        }
        else {
            return null;
            
        }
    }  
}

paginator.html

<template>
    <lightning-layout>
        <lightning-layout-item>
            <lightning-button label="Previous" icon-name="utility:chevronleft" onclick={previousHandler}></lightning-button>
        </lightning-layout-item>
        <lightning-layout-item flexibility="grow"></lightning-layout-item>
        <lightning-layout-item>
            <lightning-button label="Next" icon-name="utility:chevronright" icon-position="right" onclick={nextHandler}></lightning-button>
        </lightning-layout-item>
    </lightning-layout>
</template>

paginator.js

import { LightningElement} from 'lwc';

export default class Paginator extends LightningElement {
    previousHandler() {
        this.dispatchEvent(new CustomEvent('previous'));
    }

    nextHandler() {
        this.dispatchEvent(new CustomEvent('next'));
    }
}

<template>
    <div class="slds-p-around_medium lgc-bg">
        <lightning-input type="Currency" label="AnnualRevenue Start" value={revenueStart} name="AVStart"
            onchange={handleChange}></lightning-input>
    </div>

    <div class="slds-p-around_medium lgc-bg">
        <lightning-input type="Currency" label="AnnualRevenue End" value={revenueEnd} name="AVEnd"
            onchange={handleChange}> </lightning-input>

    </div>

    <div class="slds-p-around_medium lgc-bg">
        <template if:true={typeValues.data}>
            <lightning-combobox name="Type" label="Type" value={value} options={typeValues.data.values}
                onchange={handleChange}>
            </lightning-combobox>
        </template>
    </div>

    <div class="slds-p-around_medium lgc-bg">
        <template if:true={ratingValues.data}>
            <lightning-combobox name="Rating" label="Rating" value={value} options={ratingValues.data.values}
                onchange={handleChange}>
            </lightning-combobox>
        </template>
    </div>

    <div class="slds-p-around_medium lgc-bg">
        <template if:true={industryValues.data}>
            <lightning-combobox name="Industry" label="Industry" value={value} options={industryValues.data.values}
                onchange={handleChange}>
            </lightning-combobox>
        </template>
    </div>

    <lightning-button type="submit" variant="brand" label="Show Accounts" onclick={handleClick}></lightning-button>
    
    <template if:true={showSearchComponent}>
        <lightning-datatable key-field="Id" data={accounts} columns={columns} onsave={handleSave}
            draft-values={draftValues} hide-checkbox-column="true"></lightning-datatable>
    </template>

    <template if:false={accounts}>
        <p>No data to display</p>
    </template>

    <template if:true={loading}>
        <div class="slds-spinner_container">
            <lightning-spinner alternative-text="Loading" variant="brand" size="medium">
            </lightning-spinner>
        </div>
    </template>
</template>

import { LightningElement, wire, track, api } from 'lwc';

import { getPicklistValues } from 'lightning/uiObjectInfoApi';
import Type from '@salesforce/schema/Account.Type';
import Rating from '@salesforce/schema/Account.Rating';
import AnnualRevenue from '@salesforce/schema/Account.AnnualRevenue';

// import ChangeRating__c from '@salesforce/schema/Account.ChangeRating__c';

import { getObjectInfo } from 'lightning/uiObjectInfoApi';
import ACCOUNT_OBJECT from '@salesforce/schema/Account';
import Industry from '@salesforce/schema/Account.Industry';

import getAccountList from '@salesforce/apex/AccountForm.getAccountList';

//import getAccounts from '@salesforce/apex/AccountForm.getAccounts';
import { updateRecord } from 'lightning/uiRecordApi';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import { refreshApex } from '@salesforce/apex';

const columns = [
  { label: 'Account Name', fieldName: 'AccName', type: 'url', typeAttributes: { label: { fieldName: 'Name' } } },
  { label: 'AnnualRevenue', fieldName: 'AnnualRevenue', type: 'currency', editable: true },
  { label: 'Industry', fieldName: 'Industry' },
  { label: 'Type', fieldName: 'Type', editable: true },
  { label: 'Rating', fieldName: 'Rating', type: 'picklist', editable: true },
  { label: 'Website', fieldName: 'Website', type: 'url', editable: true },
  { label: 'ChangeRating', fieldName: 'ChangeRating__c', type: 'number', editable: true }
];

export default class AccountForm extends LightningElement {

  @track accounts;
  @track showSearchComponent = false;
  @track loading = false;
  @track revenueStart;
  @track revenueEnd;
  @api recordId;
  columns = columns;
  draftValues = [];
  accounts ;

  error;
  empty = false;


  @wire(getObjectInfo, { objectApiName: ACCOUNT_OBJECT })
  accountInfo;
  nameVal;
  typeVal;
  industryVal;


  @wire(getPicklistValues, { recordTypeId: '$accountInfo.data.defaultRecordTypeId', fieldApiName: Type })
  typeValues;

  @wire(getPicklistValues, { recordTypeId: '$accountInfo.data.defaultRecordTypeId', fieldApiName: Rating })
  ratingValues;

  @wire(getPicklistValues, { recordTypeId: '$accountInfo.data.defaultRecordTypeId', fieldApiName: Industry })
  industryValues;


  handleChange(event) {
    var fieldname = event.target.label;
    if (fieldname == 'Rating') {
      this.nameVal = event.target.value;
    } else if (fieldname == 'Type') {
      this.typeVal = event.target.value;
    } else if (fieldname == 'Industry') {
      this.industryVal = event.target.value;
    } else if (fieldname == 'AnnualRevenue Start') {
      this.revenueStart = event.target.value;
    } else if (fieldname == 'AnnualRevenue End') {
      this.revenueEnd = event.target.value;
    }
  }

  handleClick() {
    // console.log('buttom clicked');
    this.showSearchComponent = true;
    this.loading = true;
    //console.log('type--> '+this.typeVal+' rating--> '+this.nameVal+' industry--> '+this.industryVal);
    getAccountList({ type: this.typeVal, rating: this.nameVal, industry: this.industryVal, AnnualRevenueStart: this.revenueStart, AnnualRevenueEnd: this.revenueEnd })
      .then(results => {
        // console.log('account result--> '+JSON.stringify(result))
        let tempAccList = [];

        results.forEach((result) => {
          let tempAccRec = Object.assign({}, result);
          tempAccRec.AccName = '/' + tempAccRec.Id;
          tempAccList.push(tempAccRec);

        });
            this.accounts = tempAccList
        //  this.accounts=result;
            this.loading = false;
      })
      .catch(error => {
        console.log('error' + error);
        this.loading = false;
      })


  }


  handleSave(event) {
    const recordInputs = event.detail.draftValues.slice().map(draft => {
      const fields = Object.assign({}, draft);
      return { fields };
    });

    const promises = recordInputs.map(recordInput => updateRecord(recordInput));
    Promise.all(promises).then(accounts => {
      this.dispatchEvent(
        new ShowToastEvent({
          title: 'Success',
          message: 'Accounts updated',
          variant: 'success'
        })

      );
      // Clear all draft values
      this.draftValues = [];

      // Display fresh data in the datatable
      return refreshApex(this.accounts);
    }).catch(error => {
      // Handle error
    });
  }

public with sharing class AccountForm {
    @AuraEnabled
    public static List<Account>  getAccountList(String type,String rating,String industry,Integer AnnualRevenueStart,Integer AnnualRevenueEnd){
        String accQuery = 'SELECT Id,Name,Type,Rating,AnnualRevenue FROM Account';                     
        String whereClause  = '';
        
     /*   if(AnnualRevenueStart>=30000){
            whereClause =whereClause +' where AnnualRevenue>=30000';
        }
       if(AnnualRevenueEnd<=100000){
            whereClause =whereClause +' AND AnnualRevenue<=100000';
            
        }*/

        if(AnnualRevenueStart!=Null){
            whereClause=whereClause+' where AnnualRevenue>=:AnnualRevenueStart';
        }
        if(AnnualRevenueEnd!=Null){
            if(String.isEmpty(whereClause)){
            whereClause=whereClause+' WHERE AnnualRevenue<=:AnnualRevenueEnd';
        }
        else 
            {
                whereClause=whereClause+' AND AnnualRevenue<=:AnnualRevenueEnd';
            }
        }

        if(String.isNotEmpty(type)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Type = :type';
            }else{
                whereClause =whereClause + ' AND Type = :type';
            }
            
        }
        if(String.isNotEmpty(rating)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Rating = :rating';
            }else{
                whereClause =whereClause + ' AND Rating = :rating';
            }
        } 
        if(String.isNotEmpty(industry)){
            if(String.isEmpty(whereClause)){
                whereClause =whereClause +  ' WHERE Industry = :industry';
            }else{
                whereClause =whereClause + ' AND Industry = :industry';
            }
            
        } 
        String finalquery = accQuery+whereClause;
        System.debug('finalquery='+finalquery);
        
        List<Account> acclist=Database.query(finalquery);
        
        return acclist;
        
    }
}

Test Class 

@isTest
    public static void testmethod3(){
        contact con = new contact();
        con.LastName = 'Test contact';
        con.Email = 'sample@sample.com';
        insert con;
        List<Case> caseList = new List<Case>();
        for(Integer i=1; i<=200 ; i++){
            Case cs = new Case();
            cs.Status = 'New';
            cs.Origin = 'Phone';
            cs.ContactId =con.Id;
            caseList.add(cs);
        }
        
          Test.startTest();
          insert caseList;
          Test.stopTest();
    
}

Trigger

trigger CaseTrigger on Case (after insert,after delete) {
    system.debug('trigger value--> '+Trigger.isDelete+'and--> '+Trigger.IsAfter);
    CaseTriggerHandler CaseHandler = new CaseTriggerHandler();
    if(Trigger.isInsert&&Trigger.IsAfter){
        system.debug('inside insert trigger');
        CaseHandler.AfterInsert(Trigger.new);
    }
    if(Trigger.isDelete&&Trigger.IsAfter){
        system.debug('inside isDelete trigger');
        CaseHandler.AfterDelete(Trigger.old);
    }

Handler class 
  
   public class CaseTriggerHandler {
    public void AfterInsert(List<Case> case1){
        system.debug('inside CaseTriggerHandler insert trigger '+case1);
        List<Messaging.SingleEmailMessage> emails = new List<Messaging.SingleEmailMessage>();
        
        TestEmailCase__mdt testEmail = [select id, Label,NamespacePrefix,To_Address__c from TestEmailCase__mdt];
        system.debug('test case list -->'+testEmail); 
        for(Case ca:case1){
            system.debug('test email start -->'+testEmail.To_Address__c); 
            Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
            List<String> eid = new List<String>();
            
            eid.add(testEmail.To_Address__c);
            email.setToAddresses(eid);
            email.setSubject('case create');
            email.setPlainTextBody('case created');
            emails.add(email);
            system.debug('test email end -->'); 
        }
        Messaging.sendEmail(emails);
    }
    public void AfterDelete(List<Case> case1){
        List<Messaging.SingleEmailMessage> emails = new List<Messaging.SingleEmailMessage>();
        
        TestEmailCase__mdt testEmail = [select id, Label,NamespacePrefix,To_Address__c from TestEmailCase__mdt];
        system.debug(testEmail);
        
        for(Case ca:case1){
            Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();
            List<String> eid = new List<String>();
            
            eid.add(testEmail.To_Address__c);
            email.setToAddresses(eid);
            email.setSubject('case deleted');
            email.setPlainTextBody('case deleted');
            emails.add(email);
        }
        Messaging.sendEmail(emails);
    }
}

Test Class
    
  @isTest
public class CaseTriggerHandler_Test_class{

     @isTest static void setup() {
        // Create common test accounts
        List<Case> testCase = new List<Case>();
        for(Integer i=0;i<1;i++) {
            Case cas = new Case();  
            cas.Origin='Email';
            cas.Subject='Test Case';
            cas.Status = 'Closed case';
            cas.To_Address__c = 'sample@sample.com';
            testCase.add(cas);
        }
        insert testCase;  
        
        Delete testCase;
        
    }