我希望用来SqlDependency在使用数据库的其他应用程序更改某些数据时收到通知.
public class DatabaseChangesNotification : IDisposable
{
private static string chaineDeConnexion = ConfigurationManager.ConnectionStrings["TransfertContext"].ConnectionString;
private static readonly Lazy<DatabaseChangesNotification> _instance = new Lazy<DatabaseChangesNotification>(() => new DatabaseChangesNotification());
private DatabaseChangesNotification()
{
System.Diagnostics.Trace.WriteLine("--- SqlDependency START ---");
SqlDependency.Start(chaineDeConnexion);
}
public void Dispose()
{
System.Diagnostics.Trace.WriteLine("--- SqlDependency STOP ---");
SqlDependency.Stop(chaineDeConnexion);
}
public static DatabaseChangesNotification Instance
{
get
{
return _instance.Value;
}
}
public void AbonnerNotification(string requete, OnChangeEventHandler eventhandler)
{
using (SqlConnection connection = new SqlConnection(chaineDeConnexion))
{
using (SqlCommand command = new SqlCommand(requete, connection) { Notification = null }) // clear existing notifications
{
connection.Open();
var sqlDependency = new SqlDependency(command);
OnChangeEventHandler delegateAutoRemove = null;
delegateAutoRemove = (sender, e) => {
var dependency = sender as SqlDependency;
dependency.OnChange -= delegateAutoRemove;
eventhandler(sender, e);
};
sqlDependency.OnChange += delegateAutoRemove;
command.ExecuteNonQuery();
}
}
}
}
所以,使用单行我可以注册一个事件处理程序:
DatabaseChangesNotification.Instance.AbonnerNotification(@"SELECT IdUtilisateur, Code, Nom, Prenom, NomComplet, Login, Synchroniser FROM dbo.Utilisateur", OnChanges);
public void OnChanges(object sender, SqlNotificationEventArgs e){
System.Diagnostics.Trace.WriteLine("------------------------------ UPDATTEEEE -------------------------");
System.Diagnostics.Trace.WriteLine("Info: " + e.Info.ToString());
System.Diagnostics.Trace.WriteLine("Source: " + e.Source.ToString());
System.Diagnostics.Trace.WriteLine("Type: " + e.Type.ToString());
GlobalHost.ConnectionManager.GetHubContext<TransfertClientHub>().Clients.All.hello("users modified !");
//AbonnementChanges();
}
但我的问题是通知立即被解雇:
--- ABONNEMENT ---
------------------------------ UPDATTEEEE -------------------------
Info: Query
Source: Statement
Type: Subscribe
这就是我AbonnementChanges在我的事件处理程序中评论的原因OnChanges(或者它将无限循环).
我不知道问题出在哪里,因为我重置了通知({ Notification = null }),我的请求符合要求(https://msdn.microsoft.com/en-us/library/ms181122.aspx).
编辑:我想添加,select * from sys.dm_qn_subscriptions什么都不返回.
编辑:看起来它来自数据库配置,而不是来自我的实现,因为我尝试了另一个导致相同行为的实现:http://www.codeproject.com/Articles/144344/Query-Notification-using-SqlDependency -and-SqlCach
编辑:我没有看到它来自哪里,因为我使用SA是sysadmin并拥有所有权利,不是吗？
编辑:我尝试按照本教程定义与数据库的另一个连接:http://www.codeproject.com/Articles/12862/Minimum-Database-Permissions-Required-for-SqlDepen
所以我创造了两个角色:
EXEC sp_addrole 'sql_dependency_subscriber'
EXEC sp_addrole 'sql_dependency_starter'
-- Permissions needed for [sql_dependency_starter]
GRANT CREATE PROCEDURE to [sql_dependency_starter]
GRANT CREATE QUEUE to [sql_dependency_starter]
GRANT CREATE SERVICE to [sql_dependency_starter]
GRANT REFERENCES on
CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification]
to [sql_dependency_starter]
GRANT VIEW DEFINITION TO [sql_dependency_starter]
-- Permissions needed for [sql_dependency_subscriber]
GRANT SELECT to [sql_dependency_subscriber]
GRANT SUBSCRIBE QUERY NOTIFICATIONS TO [sql_dependency_subscriber]
GRANT RECEIVE ON QueryNotificationErrorsQueue TO [sql_dependency_subscriber]
GRANT REFERENCES on
CONTRACT::[http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification]
to [sql_dependency_subscriber]
然后我将user(production)添加到此角色:
- 确保我的用户是正确角色的成员.
EXEC sp_addrolemember 'sql_dependency_starter', 'production'
EXEC sp_addrolemember 'sql_dependency_subscriber', 'production'
但是通过这种联系,我有与以前相同的行为.通知是imediatly:
------------------------------ UPDATTEEEE -------------------------
Info: Query
Source: Statement
Type: Subscribe
编辑:我试过更简单的请求,如:SELECT Nom, Prenom FROM dbo.Utilisateur.以下是应该检查的表格的详细信息:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Utilisateur](
[IdUtilisateur] [uniqueidentifier] ROWGUIDCOL NOT NULL CONSTRAINT [DF_Utilisateur_IdUtilisateur] DEFAULT (newid()),
[Code] [varchar](10) NOT NULL,
[Nom] [varchar](100) NOT NULL,
[Prenom] [varchar](100) NULL,
[NomComplet] AS (([Prenom]+' ')+[Nom]),
[Login] [varchar](50) NULL,
[Synchroniser] [bit] NOT NULL CONSTRAINT [DF_Utilisateur_Synchroniser] DEFAULT ((1)),
[DATE_CREATION] [datetime] NOT NULL CONSTRAINT [DF__Utilisate__DATE___2AA1E7C7] DEFAULT (getdate()),
[DATE_DERNIERE_MODIF] [datetime] NOT NULL CONSTRAINT [DF__Utilisate__DATE___2B960C00] DEFAULT (getdate()),
[Desactive] [bit] NOT NULL CONSTRAINT [DF_Utilisateur_Desactive] DEFAULT ((0)),
CONSTRAINT [PK_Utilisateur] PRIMARY KEY CLUSTERED
(
[IdUtilisateur] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
我们可以看到有些列无法请求.这就是我不使用它的原因.
现在让我们检查一下SELECT Nom, Prenom FROM dbo.Utilisateur:
但那仍然行不通...... =(
最终编辑 - 解决方案:正如Jon Tirjan所说,这是由我的计算列引起的,NomComplet这对于Service Broker无效(即使我没有要求收到有关此列的更改的通知,这对我来说很奇怪).
Service Broker不适用于具有计算列的表.您需要NomComplet从表中删除,或将其更改为以另一种方式填充的实际列(触发器,存储过程等)
由于设置队列时发生错误,因此会立即触发通知.