(转)SqlDependency学习笔记

CREATE TABLE [dbo].[Messages](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [UserID] [varchar](50) COLLATE Chinese_PRC_CI_AS NOT NULL,
    [Message] [nvarchar](256) COLLATE Chinese_PRC_CI_AS NOT NULL,
 CONSTRAINT [PK_Messages] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) 

ON [PRIMARY]
)

using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

namespace SqlDependencyTest
{
    class Program
    {
        private static string _connStr;

        static void Main(string[] args)
        {
            _connStr = ConfigurationManager.ConnectionStrings["ConnStr"].ToString();
            SqlDependency.Start(_connStr);//传入连接字符串,启动基于数据库的监听
            UpdateGrid();

            Console.Read();
        }


        private static void UpdateGrid()
        {
            using (SqlConnection connection = new SqlConnection(_connStr))
            {
                //依赖是基于某一张表的,而且查询语句只能是简单查询语句,不能带top或*,同时必须指定所有者,即类似[dbo].[]
                using (SqlCommand command = new SqlCommand("select ID,UserID,[Message] From [dbo].[Messages]", connection))
                {
                    command.CommandType = CommandType.Text;
                    connection.Open();
                    SqlDependency dependency = new SqlDependency(command);
                    dependency.OnChange += new OnChangeEventHandler(dependency_OnChange);

                   SqlDataReader sdr = command.ExecuteReader();
                   Console.WriteLine();
                   while (sdr.Read())
                   {
                       Console.WriteLine("Id:{0}\tUserId:{1}\tMessage:{2}",sdr["ID"].ToString(), sdr["UserId"].ToString(), 

sdr["Message"].ToString());
                   }
                   sdr.Close();
                }
            }
        }


        private static void dependency_OnChange(object sender, SqlNotificationEventArgs e)
        {
            UpdateGrid();
        }
    }
}

ALTER DATABASE 数据库名称 SET NEW_BROKER WITH ROLLBACK IMMEDIATE;  
ALTER DATABASE 数据库名称 SET ENABLE_BROKER;