Link Search Menu Expand Document

DataReader


This class is used to convert the DbDataReader object into an IEnumerable<T> or IEnumerable<dynamic> object. This is the heart of the library when it comes to data extraction from the database.

It only contains one method named ToEnumerable. This method is pre-compiled AOT using Linq.Expressions.

This class is high-performant and efficient. It understands and caches the schema of your database into the memory. It also reuses all the other caches within the library during the extraction to construct and generate the most-optimal AOT compilation.

Extracting an Entities

using (var connection = new SqlConnection(connectionString))
{
    using (var reader = connection.ExecuteReader("SELECT * FROM [dbo].[Person];"))
    {
        var people = DataReader.ToEnumerable<Person>((DbDataReader) reader);
        // Do the stuffs for 'people' here
    }
}

Extracting a Dynamics

using (var connection = new SqlConnection(connectionString))
{
    using (var reader = connection.ExecuteReader("SELECT * FROM [dbo].[Person];"))
    {
        var people = DataReader.ToEnumerable((DbDataReader) reader);
        // Do the stuffs for 'people' here
    }
}

DbFields

It is also quitely important to pass the list of the DbField object in order for the compiler to skip the unnecessary DB-NULL checks.

To do this, simply pass the list of the DB fields in the dbFields argument.

using (var connection = new SqlConnection(connectionString))
{
    var dbFields = DbFieldCache.Get(connection, ClassMappedNameCache.Get<Person>(), null);
    using (var reader = connection.ExecuteReader("SELECT * FROM [dbo].[Person];"))
    {
        var people = DataReader.ToEnumerable<Person>((DbDataReader) reader,
            dbFields,
            connection.GetDbSetting());
        // Do the stuffs for 'people' here
    }
}

Please note to always pass the IDbSetting object when using the dbFields argument.