idatareader

If one needs to read data from SqlServer in a streamed fashion, there are some capabilities for that. Such as using SqlDataReader with CommandBehavior.SequentialAccess , and particularly when binary column data needs to be accessed there is the GetStream(int) method for that: var cmd = new SqlCommand(); cmd.Connection = connection; cmd.CommandText = @"select 0x0123456789 as Data"; using (var dr = cmd.ExecuteReader(CommandBehavior.SequentialAccess)) { dr.Read(); var stream = dr.GetStream(0); // access stream } But what about streaming data in the opposite direction, when one needs to feed data

(LocalVariable)ABC.string(Name)= (Idatareader)datareader.GetString(0); this name value is coming from database.. what happening here is if this name value is null while reading it's throwing an exception? I am manually doing some if condition here. I don't want to write a manual condition to check all my variables.. I am doing something like this now.. string abc = (Idatareader)datareader.GetValue(0); if(abc = null) //assiging null else assiging abc value is there something like can we write extension method for this? thanks Here is a couple extension methods that will nicely wrap up all of

How can I check for db null values in the attached code? Please understand I am a new C# convert... What this code does is takes a IDataReader object and converts and maps it to a strongly-typed list of objects. But what I am finding is it completely errors out when there are null columns returned in the reader. Converter internal class Converter<T> where T : new() { // Declare our _converter delegate readonly Func<IDataReader, T> _converter; // Declare our internal dataReader readonly IDataReader dataReader; // Build our mapping based on the properties in the class/type we've passed in to the

Can someone tell me the difference between these two pieces of code? Why use IDataReader? using (IDataReader reader = cmd.ExecuteReader()) { while (reader.Read()) { // get data from the reader } } using (SqlDataReader reader = cmd.ExecuteReader()) { while (reader.Read()) { // get data from the reader } } SqlDataReader implements the interface IDataReader . So do all other ADO.NET drivers (Oracle, MySql, etc). You can use IDataReader , so that if you plan to change database engine some day, you don't have to rewrite all your SqlDataReader references. The same goes for IDbConnection , IDbCommand

DISCLAIMER: this is a copy paste from an older stackoverflow post that isn't available anymore, but I have exaclty the same problem, so it seemed appropriate to repost it as it was never answered. I have a stored procedure that will return 4 result sets (contacts, addresses, email, phones) which is populated into a dataset. I would like to use AutoMapper to populate a complex object. public class Contact { public Guid ContactId { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public List<Address> Addresses { get; set; } public List<Phone> Phones { get;

Microsoft (and many developers) claim that the SqlDataReader.GetOrdinal method improves the performance of retrieving values from a DataReader versus using named lookups ie. reader["ColumnName"]. The question is what is the true performance difference if dealing with small, paged record sets? Is it worth the extra overhead of finding and referencing ordinal indexes throughout the code? Microsoft recommends not calling GetOrdinal within a loop. That would include indirect calls with the string indexer. You can use GetOrdinal at the top of your loop put the ordinals in an array and have the