Dataset and Datareader

Question

Hi.. What is the difference between dataset and datareader ? Please give example of both ?

Satyapriya Nayak · Answer

Hi Vineet A datareader like a dataset is an object that: 1- reads one record at a time. 2- gives the values of that records 3- Detroy the memory allocation of the record 4-it is very small object that consumes very little memory and is optimize to do it very fast.Also it uses a connection called readonly forwardonly. A Dataset on the other hand will: 1. Create a schema that define structure of the data 2. Provide memory space to store all the records of a table that resulst from the select 3. Provide memory to store more than one table 4. Provide logic to relate the records on one table with the records on another 5. Identify the primary key of the records obtained (to do so it comunicates with the sql server to obtain the key of the record. 6. Provide mechanism to update and delete the records on the table. 7. Since the dataset runs disconected mode and the records in question can be changed from another process at the same time the dataset will store the original value of the record and compare that value with the value on the database before updating the record. If the record was changed then the update will not proceed and you receive an error message. Thanks

Vineet Kumar Saini · Answer

Thanks Prabhu Raja Ji......

Prabhu Raja · Answer

Hi DataReader The ADO.NET DataReader is used to retrieve read-only(cannot update data back to datasource) and forward-only(cannot read backward/random) data from a database. Using the DataReader increases application performance and reduces system overheads. This is due to one row at a time is stored in memory. You create a DataReader by calling Command.ExecuteReader after creating an instance of the Command object. This is a connected architecture: The data is available as long as the connection with database exists. You need to open and close the connecton manually in code. DataSet The DataSet is a in-memory representation of data. It can be used with multiple data sources. That is A single DataSet can hold the data from different data sources holdng data from different databases/tables. The DataSet represents a complete set of data including related tables constraints and relationships among the tables. The DataSet can also persist and reload its contents as XML and its schema as XML Schema definition language (XSD) schema. The DataAdapter acts as a bridge between a DataSet and a data source for retrieving and saving data. The DataAdapter helps mapping the data in the DataSet to match the data in the data source. Also Upon an update of dataset it allows changing the data in the data source to match the data in the DataSet. No need to manually open and close connection in code. Hence point (8) says that it is a disconnected architecture. Fill the data in DataSet and that's it. No connection existence required Check out this Article : DataReader Vs DataSet

Javeed M Shaikh · Answer

Hi Vineet Please refer to the C# Corner article: http://www.c-sharpcorner.com/UploadFile/john_charles/DataReaderAndDataSet03102006134650PM/DataReaderAndDataSet.aspx