asp.net Sql缓存依赖(SqlCacheDependency)简介

 1. MSSql (本人用的sqlserver2008)中使用语句
ALTER DATABASE TestDB SET ENABLE_BROKER;

启用监听服务

如果启用失败或者很长时间一直在执行请执行以下语句：

ALTER DATABASE TestDB SET NEW_BROKER WITH ROLLBACK IMMEDIATE;
ALTER DATABASE TestDB SET ENABLE_BROKER;

2. 检查数据库是否启用监听服务

SELECT is_broker_enabled FROM sys.databases WHERE name = "TestDB"

(1为已启用,0为未启用)

3. 配置WebConfig

配置<connectionStrings>

<connectionStrings>

<add name="conStr" connectionString="Data Source=.;Initial Catalog=TestDB;Persist Security Info=True;User ID=sa;Password=sa" providerName="System.Data.SqlClient" />  

</connectionStrings>

<system.web> 节点下配置

<caching>       

<sqlCacheDependency enabled="true" pollTime="1000">         

<databases>           

<add name="TestDB" connectionStringName="conStr"/>         

</databases>       

</sqlCacheDependency>     

</caching>

下面上示例代码：

//定义连接字符串

string conStr = System.Configuration.ConfigurationManager.ConnectionStrings["conStr"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        SqlDependency.Start(conStr);//启动监听服务，ps：只需启动一次

        System.Web.Caching.SqlCacheDependencyAdmin.EnableNotifications(conStr);//设置通知的数据库连接，ps：只需设置一次

        System.Web.Caching.SqlCacheDependencyAdmin.EnableTableForNotifications(constr, "dbo.TableA");//设置通知的数据库连接和表，ps：只需设置一次

        string sql = "select Name from dbo.TableA";

        SqlConnection con = new SqlConnection(conStr);

        SqlCommand cmd = new SqlCommand(sql, con);

        SqlDataAdapter adapter = new SqlDataAdapter(cmd);

        DataSet ds = new DataSet();

        adapter.Fill(ds, "cache");

        System.Web.Caching.SqlCacheDependency cd = new System.Web.Caching.SqlCacheDependency("TestDB", "dbo.TableA");//建立关联

        Cache.Insert("cache", ds, cd);
    }
}

这样初始化后，更新数据库TestDB中表dbo.TableA后，缓存Cache["cache"]会失效。