For a long time I was thinking of maintaining my own blog, but unfortunately I couldn’t find time for it since I’m always busy with my office work.
Though I’m enjoying my daily life style very much, I always feel I’m not sharing my thoughts and knowledge with others. So here is my first writing in the area of
When I first heard the name
The above are exposed through different providers in
Lets start with DataReader
There are number of Data Providers in
DataReader is a one way forward only, read only method to read data from a result set. Once you get data into a DataReader it’s very important to remember that the pointer is just before the first record in the result set. You have to call .Read() which moves the pointer to the next location in the result set and returns “true” if it is a valid row.
Common way of reading data from a DaraReader is as follows:
SqlDataReader reader = command.ExecuteReader();
DataSets are database independent in memory data store which can be used to access one or many tables. It can contain one or many DataTables and these tables can contain rows and columns of data.
Data within DataSets can be updated by the user and can persist to the underplaying data store through DataAdapters. DataAdapters are database specific implementations in DataProiders.
Which to be used?
If you need one way read only access to data that we often need in ASP.
The bad side of DataReader is it keeps the database connection open till you finish entire processing of your data. So keep in mind if you have any long processing requirements DataSets may be ideal.
For windows and Smart client applications DataSets are ideal since they maintain their state whole through its life time. The dark side of using DataSet is it holds the entire data store in memory. This may cause high memory requirements if you are loading thousands and millions of data into these DataSets. Data readers are ideal in such cases.
Some Key Points
If you are passing a DataReader around your logical layers there is an inherent problem of closing the Database connection. This is one of the mistakes developers do in their developments which causes application performance and scalable issues. This issue can be solved by using the CommandBehavior.CloseConnection parameter with the ExecureReader which automatically close the database connection when closing the DataReader.
DataSets can be easily converted into XML and vise versa, this can be very useful if you want to serialize data across the wire (.ReadXML, .WriteXML methods can be used).
DataSets are accepted by ASP.