Dynamics 365 For Sales: How to merge Accounts if the subordinate record is associated with one or more active quotes?

PreOperationAccountMerge.cs

// <copyright file="PreOperationAccountMerge.cs" company="">
// Copyright (c) 2021 All Rights Reserved
// </copyright>
// <author></author>
// <date>12/17/2021 6:04:07 PM</date>
// <summary>Implements the PreOperationAccountMerge Plugin.</summary>
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.1
// </auto-generated>

using System;
using System.ServiceModel;
using Microsoft.Xrm.Sdk;
using Microsoft.Xrm.Sdk.Query;

namespace MergePoc.Plugins
{

    /// <summary>
    /// PreOperationAccountMerge Plugin.
    /// </summary>    
    public class PreOperationAccountMerge: PluginBase
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="PreOperationAccountMerge"/> class.
        /// </summary>
        /// <param name="unsecure">Contains public (unsecured) configuration information.</param>
        /// <param name="secure">Contains non-public (secured) configuration information. 
        /// When using Microsoft Dynamics 365 for Outlook with Offline Access, 
        /// the secure string is not passed to a plug-in that executes while the client is offline.</param>
        public PreOperationAccountMerge(string unsecure, string secure)
            : base(typeof(PreOperationAccountMerge))
        {
            
           // TODO: Implement your custom configuration handling.
        }


        /// <summary>
        /// Main entry point for he business logic that the plug-in is to execute.
        /// </summary>
        /// <param name="localContext">The <see cref="LocalPluginContext"/> which contains the
        /// <see cref="IPluginExecutionContext"/>,
        /// <see cref="IOrganizationService"/>
        /// and <see cref="ITracingService"/>
        /// </param>
        /// <remarks>
        /// For improved performance, Microsoft Dynamics 365 caches plug-in instances.
        /// The plug-in's Execute method should be written to be stateless as the constructor
        /// is not called for every invocation of the plug-in. Also, multiple system threads
        /// could execute the plug-in at the same time. All per invocation state information
        /// is stored in the context. This means that you should not use global variables in plug-ins.
        /// </remarks>
        protected override void ExecuteCdsPlugin(ILocalPluginContext localContext)
        {
            if (localContext == null)
            {
                throw new InvalidPluginExecutionException(nameof(localContext));
            }
            // Obtain the tracing service
            ITracingService tracingService = localContext.TracingService;

            try
            {
                // Obtain the execution context from the service provider.  
                IPluginExecutionContext context = (IPluginExecutionContext)localContext.PluginExecutionContext;

                // Obtain the organization service reference for web service calls.  
                IOrganizationService currentUserService = localContext.CurrentUserService;

                if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is EntityReference)
                {
                    EntityReference entityReferenceMaster = (EntityReference)context.InputParameters["Target"];
                    Guid GuidSubOrdinate = (Guid)context.InputParameters["SubordinateId"];

                    //Define Condition Values
                    //active quotes
                    var query_statecode = 1;
                    //related to the subAccount
                    var query_msdyn_account = GuidSubOrdinate;
                    //Instantiate QueryExpression query
                    var query = new QueryExpression("quote");
                    //!Add all columns to query.ColumnSet
                    query.ColumnSet.AllColumns = false;
                    // Define filter query.Criteria
                    query.Criteria.AddCondition("statecode", ConditionOperator.Equal, query_statecode);
                    query.Criteria.AddCondition("msdyn_account", ConditionOperator.Equal, query_msdyn_account);

                    var quotes = currentUserService.RetrieveMultiple(query);
                    foreach (var quote in quotes.Entities)
                    {
                        //move accounts from the subAccount to the Master Account
                        quote["msdyn_account"] = new EntityReference("account", entityReferenceMaster.Id);
                        quote["customerid"] = new EntityReference("account", entityReferenceMaster.Id);
                        //Update Before the merge validation
                        currentUserService.Update(quote);

                    }
                }
            }
            // Only throw an InvalidPluginExecutionException. Please Refer https://go.microsoft.com/fwlink/?linkid=2153829.
            catch (Exception ex)
            {
                tracingService?.Trace("An error occurred executing Plugin MergePoc.Plugins.PreValidationaccountMerge : {0}", ex.ToString());
                throw new InvalidPluginExecutionException("An error occurred executing Plugin MergePoc.Plugins.PreValidationaccountMerge .", ex);
            }
        }
    }
}