二开案例.服务插件.高并发下控制单据编号重复问题

【应用场景】

业务单据通常会在保存操作上配置编码唯一校验器，用于控制单据编号重复的问题，但是在WebApi高并发下，由于校验器的机制问题，使得校验结果具有一定的滞后性，因此仍有可能会产生重复单号的单据。此时，依赖数据库的唯一索引控制单据编号重复，是最高效，最佳的选择。

【案例演示】

采购订单，通过在数据库新建单据编号表，并给单据编号字段设置为主键，依托数据库的主键的数据唯一性检查，进行高并发下的单据编号重复控制。

【实现步骤】

<1>编写服务插件，代码如下。

using Kingdee.BOS;
using Kingdee.BOS.App.Data;
using Kingdee.BOS.Core.DynamicForm.PlugIn;
using Kingdee.BOS.Core.DynamicForm.PlugIn.Args;
using Kingdee.BOS.Core.Metadata.FieldElement;
using Kingdee.BOS.Core.Metadata.FormElement;
using Kingdee.BOS.Orm.DataEntity;
using Kingdee.BOS.Util;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Transactions;
namespace Jac.XkDemo.BOS.App.PlugIn
{
    /// <summary>
    /// 【服务插件】高并发下控制单据编号重复问题(保存)
    /// </summary>
    [Description("【服务插件】高并发下控制单据编号重复问题(保存)"), HotUpdate]
    public class BillNoUniqueSaveServicePlugIn : AbstractOperationServicePlugIn
    {
        public override void EndOperationTransaction(EndOperationTransactionArgs e)
        {
            base.EndOperationTransaction(e);
            var billNoField = this.BusinessInfo.GetBillNoField() as BillNoField;
            if (billNoField == null)
            {
                return;
            }
            var formId = this.BusinessInfo.GetForm().Id;
            #region 先删
            string ids;
            if (this.BusinessInfo.GetForm().PkFieldType == EnumPkFieldType.STRING)
            {
                ids = string.Join(",", e.DataEntitys.Select(o => "'" + Convert.ToString(o[0]) + "'").ToArray());
            }
            else
            {
                ids = string.Join(",", e.DataEntitys.Select(o => Convert.ToString(o[0])).ToArray());
            }
            var sqlGetOldBillNo = string.Format("SELECT {2},{0} FROM {1} WHERE {2} IN ({3})", billNoField.FieldName, this.BusinessInfo.GetEntity(0).TableName, this.BusinessInfo.GetForm().PkFieldName, ids);
            DynamicObjectCollection oldBillNoObjs;
            using (var trans = new KDTransactionScope(TransactionScopeOption.Suppress))
            {
                oldBillNoObjs = DBUtils.ExecuteDynamicObject(Context, sqlGetOldBillNo);
            }
            if (oldBillNoObjs != null && oldBillNoObjs.Count > 0)
            {
                var dicOld = new Dictionary<string, string>();
                foreach (var obj in oldBillNoObjs)
                {
                    var billNo = Convert.ToString(obj[1]);
                    if (string.IsNullOrWhiteSpace(billNo))
                    {
                        continue;
                    }
                    dicOld[Convert.ToString(obj[0])] = Convert.ToString(obj[1]);
                }
                var needDeleteBillNos = new List<string>();
                foreach (var dataEntity in e.DataEntitys)
                {
                    var id = Convert.ToString(dataEntity[0]);
                    var billNo = Convert.ToString(dataEntity[billNoField.PropertyName]);
                    if (dicOld.ContainsKey(id) && dicOld[id] != billNo)
                    {
                        // 单号被修改，旧单号删除
                        needDeleteBillNos.Add(dicOld[id]);
                    }
                }
                if (needDeleteBillNos.Count > 0)
                {
                    var sqlDeleteOldBillNo = string.Format("DELETE FROM T_JAC_BILLNO_UNIQUECHECK WHERE FOBJECTID='{0}' AND FBILLNO IN ({1})", formId, string.Join(",", needDeleteBillNos.Select(o => "'" + o + "'")));
                    DBUtils.Execute(Context, sqlDeleteOldBillNo);
                }
            }
            #endregion
            #region 再增
            var sqlTemplate = "INSERT INTO T_JAC_BILLNO_UNIQUECHECK (FOBJECTID,FBILLNO) VALUES (@FOBJECTID,@FBILLNO)";
            var sqlObjs = new List<SqlObject>();
            foreach (var dataEntity in e.DataEntitys)
            {
                var billNo = dataEntity[billNoField.PropertyName] as string;
                if (!string.IsNullOrWhiteSpace(billNo))
                {
                    var sqlObj = new SqlObject(sqlTemplate, new SqlParam("@FOBJECTID", KDDbType.AnsiString, formId));
                    sqlObj.Param.Add(new SqlParam("@FBILLNO", KDDbType.String, billNo));