asp.net Sql缓存依赖(SqlCacheDependency)简介
1. sqlserver(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
下面上示例代码：< caching > < sqlCacheDependency enabled ="true" pollTime ="1000" > < databases > < add name ="TestDB" connectionStringName ="conStr" /> </ databases > </ sqlCacheDependency > </ caching >
这样初始化后，更新数据库TestDB中表dbo.TableA后，缓存Cache["cache"]会失效。// 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); } }