adn*_*nan 5 c# sqldependency signalr kendo-grid
我有场景使用2个不同的SqlDependencies与2个不同的数据库连接,但调用一个函数.
我希望第一个数据库使用SqlDependency获取更新,然后在第一个数据库更改时同步第二个数据库,那么在第二个数据库更新时我想通过Signalr在客户端加载Kendo Grid的更改,简单的过程正在运行,但是第一次DB1更改它同步DB2然后DB2通知在客户端显示更改,但同样的过程在第二次更改DB1时,SqlDependency调用3次并通知客户端3次,第3次更改DB1其SqlDepency调用6时间或更长时间,表示下次更改后3到SqlDependency调用infite时间:
EmailHub(DB2 Hub)
public class EmailHub : Hub
{
private static string _connStringDB2 = ConfigurationManager.ConnectionStrings["MyDB2"].ToString();
[HubMethodName("updateRecords")]
public static void UpdateRecords()
{
IHubContext context = GlobalHost.ConnectionManager.GetHubContext<EmailHub>();
context.Clients.All.getUpdates();
}
}
HMailHub(DB1集线器)
public class HMailHub : Hub
{
private static string _connStringDB1 = ConfigurationManager.ConnectionStrings["MyDB1"].ToString();
[HubMethodName("updateRecords")]
public static void UpdateRecords()
{
IHubContext context = GlobalHost.ConnectionManager.GetHubContext<EmailHub>();
context.Clients.All.getUpdates();
}
}
GetEmailMessagesSQL(DB2函数)
public IEnumerable<EmailAflAwmMessageDM> GetEmailMessagesByAccountSQL(string emailid)
{
var messages = new List<EmailAflAwmMessageDM>();
// sync hmailDb to LocalDb by EmailAccountId
HMailServerSync objEmailSync = new HMailServerSync();
objEmailSync.GetEmailMessagesByAccount(Guid.Parse(emailid));
// stop all Sql dependencies before start new one
SqlDependency.Stop(_connStringDB1);
SqlDependency.Stop(_connStringDB2);
//hmailDB service(DB1 sql function call)
hmailsyncService(emailid);
using (var connection = new SqlConnection(_connString))
{
connection.Open();
using (var command = new SqlCommand(SQL.emailmessagesbyaccount_sql(), connection))
{
command.Parameters.Add(new SqlParameter("@emailaccountid", emailid));
command.Notification = null;
var dependency = (dynamic)null;
SqlDependency.Start(_connStringDB2);
dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(dependencyemailmessage_OnChange);
if (connection.State == ConnectionState.Closed)
connection.Open();
using (var reader = command.ExecuteReader())
messages = reader.Cast<IDataRecord>()
.Select(x => new EmailAflAwmMessageDM()
{
to_msg = x.GetString(0),
from_msg = x.GetString(1),
subject = x.GetString(2),
msg_date = x.GetDateTime(3)
}).ToList();
}
connection.Close();
}
return messages;
}
DB2 SqlDependency
private void dependencyemailmessage_OnChange(object sender, SqlNotificationEventArgs e)
{
if (e.Type == SqlNotificationType.Change)
{
EmailHub.UpdateRecords();
}
}
HMailDB(DB1 SQL函数)
public void GetHmailMessagesByAccountSQL(int hmailid)
{
using (var connection = new SqlConnection(_connStringDB1))
{
connection.Open();
using (var command = new SqlCommand(SQL.hmailmessages_sql(), connection))
{
command.Parameters.Add(new SqlParameter("@messageaccountid", hmailid));
command.Notification = null;
var dependency = (dynamic)null;
SqlDependency.Start(_connStringDB1);
dependency = new SqlDependency(command);
dependency.OnChange += new OnChangeEventHandler(dependencyhmailmessage_OnChange);
if (connection.State == ConnectionState.Closed)
connection.Open();
var reader = command.ExecuteReader();
}
connection.Close();
}
}
DB1 SqlDependency
private void dependencyhmailmessage_OnChange(object sender, SqlNotificationEventArgs e)
{
if (e.Type == SqlNotificationType.Change)
{
EmailHub.UpdateRecords();
}
}
客户端代码(Kendo Grid)
<div id="grid">
</div>
@Scripts.Render("~/bundles/signalr")
<script src="~/signalr/hubs"></script>
<script type="text/javascript">
var emailid = '@TempData["DefaultEmailId"]'
$(function () {
// Declare a proxy to reference the hub.
var notifications = $.connection.emailHub;
// Create a function that the hub can call to broadcast messages.
notifications.client.getUpdates = function () {
alert("notification called");
updateGridData();
};
// Start the connection.
$.connection.hub.start().done(function () {
alert("connection started")
updateGridData();
}).fail(function (e) {
alert(e);
});
function updateGridData() {
datasource = new kendo.data.DataSource({
transport: {
read:
{
url: crudServiceBaseUrl + "EmailAflAwmMessage/getMessages/?emailid=" + emailid,
dataType: "json",
},
update:
{
url: crudServiceBaseUrl + "EmailAflAwmMessage/Put/",
type: "PUT",
parameterMap: function (options, operation) {
if (operation !== "read" && options.models) {
return {
models: kendo.stringify(options.models)
};
}
}
},
},
schema:
{
model:
{
id: "EmailMessageId",
fields: {
EmailMessageId: { editable: true, nullable: false, type: "guid" },
subject: { editable: true, nullable: true, type: "string" },
to_msg: { editable: true, nullable: false, type: "string" },
}
}
}
});
$("#grid").kendoGrid({
dataSource: datasource,
editable: "popup",
toolbar: ["create"],
columns: [
{
field: "to_msg",
title: "to_msg",
},
{
field: "from_msg",
title: "from_msg",
},
{
field: "subject",
title: "subject",
},
{
field: "msg_date",
title: "msg_date",
}
],
height: "400px",
pageable: {
refresh: true,
pageSizes: true,
buttonCount: 5
},
}).data("kendoGrid");
}
});
在Kendo Grid中使用的API方法
public IEnumerable<EmailAflAwmMessageDM> GetMessages(string emailid)
{
return objEmailSQLFunction.GetEmailMessagesByAccountSQL(emailid);
}
我已经详细解释了上面的问题.请指导我解决或建议我任何备用优化解决方案,我感谢您宝贵的时间和精力.谢谢
我在使用 SQL 依赖项时遇到了同样的问题。
所以我创建了一个类来有效地使用它。
注意：您应该致电SqlDependency.Start(_connStringDB1);（Application_Start仅一次）
public class LiveData
{
public string SprocOrQuery { get; set; }
private Dictionary<string, object> par = new Dictionary<string, object>();
public Dictionary<string, object> Parameters { get { return par; } set { par = value; } }
public string SqlConn { get; set; }
public Action<DataTable> ActionOnData { get; private set; }
public bool EffectedOnly { get; set; }
public DateTime EffectDate = DateTime.Now;
public int EffectedCyles { get; private set; }
public DataTable Data { get; private set; }
public List<SqlNotificationInfo> Events { get; set; }
public SqlNotificationInfo CurrentEvent { get; private set; }
public LiveData() { }
public LiveData(string sprocOrQuery, Dictionary<string, object> parameters = null, string connection = null)
{
SprocOrQuery = sprocOrQuery;
Parameters = parameters;
SqlConn = connection;
}
public Task Start(Action<DataTable> actionOnData = null)
{
return Task.Factory.StartNew(() =>
{
try
{
if (ActionOnData == null) ActionOnData = actionOnData;
SqlConnection sqlConn = new SqlConnection(SqlConn);
using (SqlCommand cmd = new SqlCommand(SprocOrQuery, sqlConn) { CommandType = SprocOrQuery.Contains(" ") ? CommandType.Text : CommandType.StoredProcedure, CommandTimeout = 60 })
{
if (Parameters != null && Parameters.Count > 0)
foreach (var key in Parameters.Keys) cmd.Parameters.Add(new SqlParameter(key, Parameters[key]));
if (EffectedOnly) /* Sproc or Query must accept @UpdateDate parameter as DateTime */
{
if (cmd.Parameters.Contains("EffectDate")) cmd.Parameters["EffectDate"].Value = EffectDate;
else cmd.Parameters.Add(new SqlParameter("EffectDate", EffectDate));
}
cmd.Notification = null;
Data = new DataTable();
new SqlDependency(cmd).OnChange += OnChange;
if (sqlConn.State == ConnectionState.Closed) sqlConn.Open();
Data.Load(cmd.ExecuteReader(CommandBehavior.CloseConnection));
}
if ((Events == null || Events.Contains(CurrentEvent)))
{
if (EffectedCyles > 0) EffectDate = DateTime.Now;
EffectedCyles++;
if (ActionOnData != null) ActionOnData.Invoke(Data);
}
}
catch (Exception ex)
{
Logger.LogException(ex);
}
});
}
private void OnChange(object sender, SqlNotificationEventArgs e)
{
CurrentEvent = e.Info;
SqlDependency dependency = sender as SqlDependency;
dependency.OnChange -= OnChange;
Start();
}
}
用法
new LiveData()
{
SprocOrQuery = @"SELECT
t.[ID],
t.[CreateDate],
t.[UpdateDate]
FROM
dbo.Table t
INNER JOIN dbo.Group g
ON g.[ID] = t.[GroupID]
WHERE
t.[UpdateDate] >= @EffectDate",
SqlConn = "SqlConnectionString",
EffectedOnly = true,
Events = new List<SqlNotificationInfo>() { SqlNotificationInfo.Update }
}.Start(dt =>
{
/* dt is the dataTable you get for every update */
// you can run your dependencyemailmessage_OnChange logic here
});