ado.net

问题 I have a varbinary(max) field in one of my tables but I don't need it every time and I'm looking for a way to fetch it from the database only when necessary. I'm using ADO.NET Entity Framework. How to do that? 回答1: The solution was to create a separate table with the varbinary field and make 1-to-1 relationship between the tables 回答2: It is not necessarily to create separate table. You should do several steps. Let's assume that we have table 'Documents' (Id, Name, Data (varbinary)). Open EF

问题 I have a varbinary(max) field in one of my tables but I don't need it every time and I'm looking for a way to fetch it from the database only when necessary. I'm using ADO.NET Entity Framework. How to do that? 回答1: The solution was to create a separate table with the varbinary field and make 1-to-1 relationship between the tables 回答2: It is not necessarily to create separate table. You should do several steps. Let's assume that we have table 'Documents' (Id, Name, Data (varbinary)). Open EF

问题 I have the column DateTimeExpired, and I would like to create another column called "Expired" which will show "Yes" or "No" according to the expiration date - "Yes" if the date has already passed. I wrote this: DataColumn colExpirationDate = new DataColumn("DateTimeExpired", typeof(DateTime)); DataColumn colExpired = new DataColumn("Expired", typeof(string), "IIF(DateDiff(DateTimeExpired, date())>= 0,'No','Yes')"); But I get an exception "The expression contains undefined function call

问题 Alright, I finally got this code to work after hours of toiling: Dim path As String = OpenFileDialog1.FileName Dim myDataset As New DataSet() Dim strConn = New OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=" & path & ";Extended Properties=""Excel 12.0;HDR=YES;IMEX=1""") Dim myData As New OleDb.OleDbDataAdapter("SELECT * FROM [Sheet1$]", strConn) myData.Fill(myDataset) DataGridView1.DataSource = myDataset.Tables(0).DefaultView Now that I figured that out I was going to try and

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: Parameterizing a SQL IN clause? Hi, I have a query looks like this: SELECT CompanyId FROM CompanyTable WHERE CompanyName IN ('Subway', 'A & W', 'Pizzahut') Is there any way I can use sql parameters for the names list? This is not a stored proc (which I prefer but can't use in this project). When I say 'parameter', I mean parameter in the parametrized inline sql. I use MS Enterprise Library so my parametrized

问题 I have been trying to execute sql scripts from dotnet (C#) but the sql scripts could contain GO statements and I would like to be able to wrap the collection of scripts in a transaction. I found this question and the accepted answer got me going for handling the GO statements, but if I use a BeginTransaction it throws a InvalidOperationException at the "new ServerConnection" line. SqlConnection connection = new SqlConnection(connectionString); connection.Open(); SqlTransaction transaction =

问题 My program is now still running to import data from a log file into a remote SQL Server Database. The log file is about 80MB in size and contains about 470000 lines, with about 25000 lines of data. My program can import only 300 rows/second, which is really bad. :( public static int ImportData(string strPath) { //NameValueCollection collection = ConfigurationManager.AppSettings; using (TextReader sr = new StreamReader(strPath)) { sr.ReadLine(); //ignore three first lines of log file sr

问题 My program is now still running to import data from a log file into a remote SQL Server Database. The log file is about 80MB in size and contains about 470000 lines, with about 25000 lines of data. My program can import only 300 rows/second, which is really bad. :( public static int ImportData(string strPath) { //NameValueCollection collection = ConfigurationManager.AppSettings; using (TextReader sr = new StreamReader(strPath)) { sr.ReadLine(); //ignore three first lines of log file sr

问题 My program is now still running to import data from a log file into a remote SQL Server Database. The log file is about 80MB in size and contains about 470000 lines, with about 25000 lines of data. My program can import only 300 rows/second, which is really bad. :( public static int ImportData(string strPath) { //NameValueCollection collection = ConfigurationManager.AppSettings; using (TextReader sr = new StreamReader(strPath)) { sr.ReadLine(); //ignore three first lines of log file sr

问题 I'm writing some simple queries which return a single value and I'd like to get the ADO.NET ExecuteScalar method's behavior from Classic ASP's ADO libary. However, I'd prefer to not re-invent the wheel. Is it possible to instantiate ADO.NET's Command object within classic ASP? If so, how would I go about doing that? If I do need to re-implement this feature, what is the best way to do that? Here's what I'm trying to do (In VBScript): set cmd = Server.CreateObject("ADODB.Command") cmd