sqldatareader

I have an SQL query I get from a configuration file, this query usually contains 3-6 joins. I need to find at run time, based on the result set represented by SqlDataReader, to find the name of the table for each column. Here are some thing that don't work: SqlDataReader.GetName returns the column name but not the table name. SqlDataReader.GetSchemaTable returns a data table with column information - but all the table names are null. Querying information_schema doesn't help because I need data on the results of the current query (and the column names are not unique - there are columns with 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

How can I add values that a SqlDataReader returns to a generic List? I have a method where I use SqlDataReader to get CategoryID from a Category table. I would like to add all the CategoryID a generic List. This dose not work because it returns only one categoryID and that is the last one. I want to add all the categoryID to the list and then return them. How do I do that? SqlConnection connection = null; SqlDataReader reader = null; SqlCommand cmd = null; try { connection = new SqlConnection(connectionString); cmd = new SqlCommand("select CategoryID from Categories", connection ); connection

This is the scenario: We store files, e.g. relatively large documents (10-300MB), in blobs in our MSSQL database. We have a very small domain model so we use the clean SqlDataReader approach for our repository, instead of an ORM, to avoid unnecessary dependencies. We want to use the objects in server context on ASP.NET/ASP.NET MVC web pages. We do not want to temporarily store the blobs in byte[], to avoid high memory usage on the server So what I have been doing is to implement my own SqlBlobReader. It inherits Stream and IDisposable and during instantiation we must supply a SqlCommand

Dapper dot net has a buffer parameter (a bool), but as far as I can tell the only thing it does is cast the result to a list before returning it. As per the documentation : Dapper's default behavior is to execute your sql and buffer the entire reader on return. This is ideal in most cases as it minimizes shared locks in the db and cuts down on db network time. However when executing huge queries you may need to minimize memory footprint and only load objects as needed. To do so pass, buffered: false into the Query method. I'm not sure how casting the result to a list accomplishes this. Am I

I've got an ASP.NET page that has a bunch of controls that need to be populated (e.g. dropdown lists). I'd like to make a single trip to the db and bring back multiple recordsets instead of making a round-trip for each control. I could bring back multiple tables in a DataSet, or I could bring back a DataReader and use '.NextResult' to put each result set into a custom business class. Will I likely see a big enough performance advantage using the DataReader approach, or should I just use the DataSet approach? Any examples of how you usually handle this would be appreciated. If you have more