Question

我正在开发Windows软件，并且我有一个数据库。所以我想要的是，如果数据库记录已更新，我的Windows应用程序应自动检测它并检索那些更新的记录。有人可以为此提供解决方案吗？

Answer 1

检查SqlDependency类

在Sql中：

ALTER DATABASE SampleDB SET SINGLE_USER;

ALTER DATABASE SampleDB SET ENABLE_BROKER;

ALTER DATABASE SampleDB SET MULTI_USER;

CREATE QUEUE myTableMessages;

CREATE SERVICE myTableNotifications ON QUEUE myTableMessages("http://schemas.microsoft.com/SQL/Notifications/PostQueryNotification");

////

在视觉上：

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


namespace NotifyService
{
public class SqlNotifier : IDisposable
{
    public SqlCommand SqlCmd { get; set; }
    public SqlConnection SqlCon { get; set; }


    public void StartMonitoring()
    {
        SqlDependency.Start(this.SqlCon.ConnectionString);
        RegisterDependency();
    }


    private event EventHandler<SqlNotificationEventArgs> _NewNotification;
    public event  EventHandler<SqlNotificationEventArgs> NewNotification
    {
        add { this._NewNotification += value; }
        remove { this._NewNotification -= value; }
    }


    public virtual void OnNewNotification(SqlNotificationEventArgs notification)
    {  
        if (this._NewNotification != null)
            this._NewNotification(this, notification);
    }


    public void RegisterDependency()
    {
        this.SqlCmd = new SqlCommand(SqlCmd.CommandText,this.SqlCon);
        this.SqlCmd.Notification = null;


        SqlDependency dependency = new SqlDependency(this.SqlCmd);
        dependency.OnChange += this.Dependency_OnChange;


        if (this.SqlCon.State == ConnectionState.Closed)
            this.SqlCon.Open();


        this.SqlCmd.ExecuteReader();
        this.SqlCon.Close();
    }


    private void Dependency_OnChange(object sender, SqlNotificationEventArgs e)
    {
        SqlDependency dependency = (SqlDependency)sender;
        dependency.OnChange -= new OnChangeEventHandler(Dependency_OnChange);
        this.OnNewNotification(e);
        RegisterDependency();
    }


    public void Dispose()
    {
        SqlDependency.Stop(this.SqlCon.ConnectionString);
    }


}
}

/// 使用：

using NotifyService;
private SqlNotifier NS = new SqlNotifier();
NS.SqlCon = new SqlConnection(@"Data Source=127.0.0.1;Initial Catalog=SampleDB;Persist Security Info=True;User ID=sa;Password=***");
NS.SqlCmd = new SqlCommand("SELECT id, name FROM dbo.mytable");
NS.StartMonitoring();
NS.NewNotification += new EventHandler<SqlNotificationEventArgs>(DependencyEventHandler);

Windows窗体应用程序使用C＃自动获取更新的数据库记录

1 个答案: