6

我试图让 SqlDependency 对象给我通知，但到目前为止我无法让它工作。

我发送的 sql 查询是这样的：

SELECT [SocialMedia].[dbo].[Items].[Id]
  FROM [SocialMedia].[dbo].[Items]

我试过带和不带大括号，有完全限定的名称，只有变量名，以及介于两者之间的所有内容。

Id 是我在为通知创建查询文章Guid中没有看到任何提及它们不适用于 SqlDependency 对象的类型

我还尝试发送多个列，看看是否可行。 

  SELECT SocialMedia.dbo.Items.Id, 
         SocialMedia.dbo.Items.DateTimeCreated, 
         SocialMedia.dbo.Items.AuthorId
  FROM   SocialMedia.dbo.Items

这也没有奏效。

这是我的表 SQL：

USE [SocialMedia]

SET ANSI_NULLS ON
SET QUOTED_IDENTIFIER ON
SET ANSI_PADDING ON

CREATE TABLE [dbo].[Items](
    [Id] [uniqueidentifier] NOT NULL,
    [DateTimeCreated] [datetimeoffset](7) NOT NULL,
    [AuthorId] [uniqueidentifier] NOT NULL,
    [Source] [varchar](max) NOT NULL,
    [PlaceId] [uniqueidentifier] NULL,
    [FullText] [varchar](max) NOT NULL,
    [Geography] [geography] NULL,
    [DateTimeAdded] [datetime] NULL,
 CONSTRAINT [PK_Items] 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]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

GO

ALTER TABLE [dbo].[Items]  WITH CHECK ADD  CONSTRAINT [FK_Items_Places] 
FOREIGN KEY([PlaceId]) REFERENCES [dbo].[Places] ([Id])

ALTER TABLE [dbo].[Items] CHECK CONSTRAINT [FK_Items_Places]

GO
ALTER TABLE [dbo].[Items]  WITH CHECK ADD  CONSTRAINT [FK_Items_Users] 
FOREIGN KEY([AuthorId]) REFERENCES [dbo].[Users] ([Id])

ALTER TABLE [dbo].[Items] CHECK CONSTRAINT [FK_Items_Users]

我的数据库：

USE [master]
GO

CREATE DATABASE [SocialMedia]
 CONTAINMENT = NONE
 ON  PRIMARY 
 ( NAME = N'SocialMedia', 
   FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL11.DENALI\MSSQL\DATA\SocialMedia.mdf' , 
    SIZE = 1110016KB , MAXSIZE = UNLIMITED, FILEGROWTH = 1024KB )
 LOG ON 
( NAME = N'SocialMedia_log', 
  FILENAME = N'C:\Program Files\Microsoft SQL Server\MSSQL11.DENALI\MSSQL\DATA\SocialMedia_log.ldf' , 
  SIZE = 123648KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)
GO

ALTER DATABASE [SocialMedia] SET COMPATIBILITY_LEVEL = 110
GO

IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled')) BEGIN
  EXEC [SocialMedia].[dbo].[sp_fulltext_database] @action = 'enable'
END
GO

ALTER DATABASE [SocialMedia] SET ANSI_NULL_DEFAULT OFF 
ALTER DATABASE [SocialMedia] SET ANSI_NULLS ON 
ALTER DATABASE [SocialMedia] SET ANSI_PADDING ON 
ALTER DATABASE [SocialMedia] SET ANSI_WARNINGS ON 
ALTER DATABASE [SocialMedia] SET ARITHABORT ON 
ALTER DATABASE [SocialMedia] SET AUTO_CLOSE OFF 
ALTER DATABASE [SocialMedia] SET AUTO_CREATE_STATISTICS ON 
ALTER DATABASE [SocialMedia] SET AUTO_SHRINK OFF 
ALTER DATABASE [SocialMedia] SET AUTO_UPDATE_STATISTICS ON 
ALTER DATABASE [SocialMedia] SET CURSOR_CLOSE_ON_COMMIT OFF 
ALTER DATABASE [SocialMedia] SET CURSOR_DEFAULT  GLOBAL 
ALTER DATABASE [SocialMedia] SET CONCAT_NULL_YIELDS_NULL ON 
ALTER DATABASE [SocialMedia] SET NUMERIC_ROUNDABORT OFF 
ALTER DATABASE [SocialMedia] SET QUOTED_IDENTIFIER ON 
ALTER DATABASE [SocialMedia] SET RECURSIVE_TRIGGERS OFF 
ALTER DATABASE [SocialMedia] SET  ENABLE_BROKER 
ALTER DATABASE [SocialMedia] SET AUTO_UPDATE_STATISTICS_ASYNC OFF 
ALTER DATABASE [SocialMedia] SET DATE_CORRELATION_OPTIMIZATION OFF 
ALTER DATABASE [SocialMedia] SET TRUSTWORTHY OFF 
ALTER DATABASE [SocialMedia] SET ALLOW_SNAPSHOT_ISOLATION OFF 
ALTER DATABASE [SocialMedia] SET PARAMETERIZATION SIMPLE 
ALTER DATABASE [SocialMedia] SET READ_COMMITTED_SNAPSHOT OFF 
ALTER DATABASE [SocialMedia] SET HONOR_BROKER_PRIORITY OFF 
ALTER DATABASE [SocialMedia] SET RECOVERY FULL 
ALTER DATABASE [SocialMedia] SET  MULTI_USER 
ALTER DATABASE [SocialMedia] SET PAGE_VERIFY CHECKSUM  
ALTER DATABASE [SocialMedia] SET DB_CHAINING OFF 
ALTER DATABASE [SocialMedia] SET FILESTREAM( NON_TRANSACTED_ACCESS = OFF ) 
ALTER DATABASE [SocialMedia] SET TARGET_RECOVERY_TIME = 0 SECONDS 
ALTER DATABASE [SocialMedia] SET  READ_WRITE

我用来运行它的代码：

string connString = ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString;
conn = new SqlConnection(connString);
conn.Open(); // open new connection and create command to notify about all new Chat-Messages in -ROOM_NUMBER- const
using (var sqlCommand = new SqlCommand(GetSearchQueryString(searchItems), conn))
{
    var sqlDependency = new SqlDependency(sqlCommand
    //handle onChange event - this will be fired whenever there is a change in database that affacts our query
    sqlDependency.OnChange += (sender, e) =>
    {
        //change detected - get all messages...
        try
        {

            var sql = GetSearchQueryString(searchItems);
            int count = _entities.ExecuteStoreQuery<Guid>(sql).Count();

            AsyncManager.Parameters["count"] = count;
        }
        finally
        {
            AsyncManager.OutstandingOperations.Decrement();
        }
    };
    sqlCommand.ExecuteNonQuery();
}

我SqlDependency.Start(ConfigurationManager.ConnectionStrings["ApplicationServices"].ConnectionString);在程序的早些时候打电话。

我错过了什么吗？我觉得我错过了一些明显的东西......

4

5 回答 5

11

我发现 SqlDependency 非常脆弱。有时，如果您做了一些无效的事情，您总是会立即收到通知。没有错误信息。

尝试从查询中删除数据库名称限定。像这样引用表格：dbo.Items

于 2012-04-18T23:45:06.037 回答
2

看起来您使用的是三个部分名称，即

[SocialMedia].[dbo].[Items].[Id]

该文档明确指出您需要使用两个部分名称，因此更改为

[SocialMedia].[Items].[Id]

于 2012-07-18T14:44:12.453 回答
1

迈克尔的回答是一个很好的来源，但微软没有提到一件事：

SQL 代理将拒绝具有计算列的表上的 SELECT 语句

如果您尝试，您将获得一个带有 info=Query、type=Subscribe 的 SqlNotificationEventArgs，并且像我一样，您将花费数小时试图找出该语句出了什么问题，而罪魁祸首是计算列。

于 2012-08-30T11:12:27.993 回答
-1

在您的 SQL Server 中执行

ALTER DATABASE YOURDBNAME SET ENABLE_BROKER WITH ROLLBACK IMMEDIATE

于 2014-11-20T05:43:36.707 回答