Essential ADO.NET

5.11. Should You Use DataSet or DataReader?

A contentious issue among programmers is when to use DataReader and when to use DataAdapter and DataSet. As almost always, the answer is, “It depends.” Let's look at the consequences of using each and the situations in which you might prefer one or the other. Again, we'll use SQL Server as the sample data store.

DataReader is a lightweight stream of data that can be read into an array. DataTable simply provides the array and captures the TDS describe packets to populate the data type. As discussed earlier in this chapter, neither one lets you preallocate the array because the number of rows that will be returned (at least in the case of SQL Server) is unknown when a SELECT statement returns. It is not ...