このエラーが発生するのはなぜですか？何か案が ？！
（sqldatasourceを使用してフォームからデータベースにデータを挿入します）
を設定しましたがShowWarningOnFailure="true"、エラーウィンドウにこれが表示されます。
{
serviceResponse: {
success: false,
message: "System.Exception: Sequence contains more than one matching element ---> System.InvalidOperationException: Sequence contains more than one matching element\r\n at System.Linq.Enumerable.Single[TSource](IEnumerable1 source, Func2 predicate)\r\n at Ext.Net.Store.InsertCallback(Int32 recordsAffected, Exception exception) in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 1053\r\n at System.Web.UI.DataSourceView.Insert(IDictionary values, DataSourceViewOperationCallback callback)\r\n at Ext.Net.Store.MakeInsertes(IDataSource ds, JArray data) in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 982\r\n at Ext.Net.Store.MakeChanges() in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 839\r\n at Ext.Net.Store.DoSaving(String action, String jsonData, JToken parameters) in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 793\r\n --- End of inner exception stack trace ---\r\n at Ext.Net.Store.DoSaving(String action, String jsonData, JToken parameters) in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 806\r\n at Ext.Net.Store.RaiseAjaxPostBackEvent(String eventArgument) in C:\Users\Geoffrey McGill\Documents\Visual Studio 2010\Projects\Ext.NET\v2\Ext.Net\Ext\Data\Store.cs:line 1131",
data:
}
}