目前仅支持SQL Server，后续会支持MySQL和Oracle，Nuget上可以下载安装

或者使用Nuget命令添加包

dotnet add package Kogel.Subscribe.Mssql --version 0.0.0.1

 可以用来处理DB主从同步，跨库同步，数据备份，同步ES，缓存刷新等等

(一)定义需要监听表的实体类 

 /// <summary>
    /// 
    /// </summary>
    [Display(Rename = "t_oms_order_detail")]
    [ElasticsearchType(RelationName = "t_oms_order_detail", IdProperty = "Id")]
    public class OmsOrderDetail : IBaseEntity<OmsOrderDetail, int>
    {
        /// <summary>
        /// 
        /// </summary>
        [Identity]
        [Display(Rename = "id")]
        [Nest.PropertyName("id")]
        public override int Id { get; set; }

        /// <summary>
        /// 
        /// </summary>
        [Display(Rename = "name")]
        [Nest.PropertyName("name")]
        public string Name { get; set; }

        /// <summary>
        /// 
        /// </summary>
        [Display(Rename = "trade_id")]
        [Nest.PropertyName("trade_id")]
        public int? TradeId { get; set; }

        /// <summary>
        /// 
        /// </summary>
        [Display(Rename = "descption")]
        [Nest.PropertyName("descption")]
        public string Descption { get; set; }

        /// <summary>
        /// 
        /// </summary>
        [Display(Rename = "create_time")]
        [Nest.PropertyName("create_time")]
        public DateTime CreateTime { get; set; }
    }

[Display]和[Identity]属于Kogel.Dapper.Extension的特性如果[想了解更多请点击]，[ElasticsearchType]和[Nest.PropertyName]属于Elasticsearch特性，如果没用到可以忽略

(二)定义表订阅

    /// <summary>
    /// 定义表订阅
    /// </summary>
    public class OmsOrderDetailSubscribe : Subscribe<OmsOrderDetail>
    {
        /// <summary>
        /// 设置连接配置
        /// </summary>
        /// <param name="builder"></param>
        public override void OnConfiguring(OptionsBuilder<OmsOrderDetail> builder)
        {
            //此连接字符串账号需要有管理员权限
            builder.BuildConnection("数据库连接字符串");
        }
    }

如果需要此表对应多张分表可以设置

//配置所有表分片
builder.BuildShards(new List<string>
            {
                "t_oms_order_detail_1",
                "t_oms_order_detail_2",
                "t_oms_order_detail_3"
            })

(1).如果想推送订阅到RabbitMQ中

builder.BuilderRabbitMQ(new RabbitMQ.Client.ConnectionFactory
            {
                HostName = "localhost",
                UserName = "guest",
                Password = "guest"
            })

可以通过BuildTopic设置交换机名称

builder.BuildTopic("kogel_subscribe_order_detail")

(2).如果想推送订阅到Kafka中

builder.BuildKafka(new ProducerConfig
            {
                BootstrapServers = "localhost:9092",
                Acks = Acks.None
            })

可以通过BuildTopic设置Topic名称

builder.BuildTopic("kogel_subscribe_order_detail")

(3).如果想推送订阅到Elasticsearch中

 builder.BuildElasticsearch(new ElasticsearchConfig<OmsOrderDetail>
            {
                Settings = new Nest.ConnectionSettings(new Uri("http://localhost:9200/")),
            })

如果有设置Basic授权

builder.BuildElasticsearch(new ElasticsearchConfig<OmsOrderDetail>
            {
                Settings = new Nest.ConnectionSettings(new Uri("http://localhost:9200/"))
                    .BasicAuthentication("账号","密码")
            })

如果想根据自己定义的分片逻辑插入到多个ES索引中可以通过WriteInterceptor

/// <summary>
        /// 设置连接配置
        /// </summary>
        /// <param name="builder"></param>
        public override void OnConfiguring(OptionsBuilder<OmsOrderDetail> builder)
        {
            //此连接字符串账号需要有管理员权限
            builder.BuildConnection("数据库连接字符串");
            //定义推送ES
            builder.BuildElasticsearch(new ElasticsearchConfig<OmsOrderDetail>
            {
                Settings = new Nest.ConnectionSettings(new Uri("http://localhost:9200/"))
                    .BasicAuthentication("账号", "密码"),
                WriteInterceptor = message => WriteInterceptor(message)
            });
        }

        /// <summary>
        /// 定义自己的索引逻辑
        /// </summary>
        /// <param name="messages"></param>
        /// <returns></returns>
        private EsSubscribeMessage<OmsOrderDetail> WriteInterceptor(SubscribeMessage<OmsOrderDetail> message)
        {
            string esIndexName;
            //这里写自己索引分片的业务逻辑
            if (message.Result.Id % 3 == 0)
            {
                esIndexName = $"kogel_orders_2";
            }
            else
            {
                esIndexName = $"kogel_orders_1";
            }
            return message.ToEsSubscribeMessage(esIndexName);
        }

并且ES索引不存在的时候会动态创建

(4).如果想自定义实现订阅逻辑，在可以Subscribe订阅类中重写

/// <summary>
        /// 订阅变更 （每一次sql的执行会触发一次Subscribe）
        /// </summary>
        /// <param name="messageList">消息列表表示所有影响到的数据变更(会受BuildLimit限制，没有查询完成的会在下一次查出)</param>
        public override void Subscribes(List<SubscribeMessage<T>> messageList)
        {
            foreach (var message in messageList)
            {
                Console.WriteLine($"执行动作:{message.Operation}，更新的表:{message.TableName}，更新的id:{message.Result.GetId()}");
            }
        }

以上订阅的优先级:

(三)订阅启动

启动监听所有继承自Subscribe<T>的类，在应用程序启动时执行即可

ApplicationProgram.Run();

启动前需要确保DB已经开启了SQL Server Agent

windows环境可以通过cmd命令开启

net start SQLSERVERAGENT

linux或docker环境可以通过以下命令开启

/opt/mssql/bin/mssql-conf set sqlagent.enabled true

如果是基础BaseSubscribe<T>中间基类需要定义成abstract，例如

  /// <summary>
    /// 基础配置类需要定义成abstract
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public abstract class BaseSubscribe<T> : Subscribe<T>
        where T : class, IBaseEntity
    {
    }

关闭监听，在应用程序退出时执行即可

ApplicationProgram.Close();

(四)其他配置

builder.BuildCdcConfig(new CdcConfig
            {
                //扫描间隔(每次扫描变更表的间隔，单位毫秒) 默认10000毫秒/10秒
                ScanInterval = 10000,

                //变更捕捉文件在DB保存的时间（默认三天）
                Retention = 60 * 24 * 3,

                //是否首次扫描表全部数据再监听变更（默认false）
                IsFirstScanFull = false,

                //每次检索的变更量（默认10条）
                Limit = 10,

                //变更扫描的偏移量位置（默认从最后中止处开始）
                OffsetPosition = OffsetPositionEnum.Abort
            })