ASP.NET: Difference Between DataReader, DataSet, DataAdapter and DataTable in C#

Original article written By Santosh Kumar on Jul 25, 2013

C# ADO.NET Command

The Command Object in ADO.NET executes SQL statements and Stored Procedures against the data source specified in the C# Connection Object. The Command Object requires an instance of a C# Connection Object for executing the SQL statements .

In order to retrieve a resultset or execute an SQL statement against a Data Source , first you have to create a Connection Object and open a connection to the Data Source specified in the connection string. Next step is to assign the open connection to the connection property of the Command Object . Then the Command Object can execute the SQL statements. After the execution of the SQl statement, the Command Object will return a result set . We can retrieve the result set using a Data Reader .

csharp-command

The Command Object has a property called CommandText , which contains a String value that represents the command that will be executed against the Data Source. When theCommandType property is set to StoredProcedure, the CommandText property should be set to the name of the stored procedure.

Click the following links to see some important built in methods uses in the Command Object to execute the SQL statements.

DataReader

DataReader is used to read the data from database and it is a read and forward only connection oriented architecture during fetch the data from database. DataReader will fetch the data very fast when compared with dataset. Generally we will use ExecuteReader object to bind data to datareader.

To bind DataReader data to GridView we need to write the code like as shown below:

 

Protected void BindGridview()

{

using (SqlConnection conn = new SqlConnection(“Data Source=abc;Integrated Security=true;Initial Catalog=Test”))

{

con.Open();

SqlCommand cmd = new SqlCommand(“Select UserName, First Name,LastName,Location FROM Users”, conn);

SqlDataReader sdr = cmd.ExecuteReader();

gvUserInfo.DataSource = sdr;

gvUserInfo.DataBind();

conn.Close();

}

}

  • Holds the connection open until you are finished (don’t forget to close it!).
  • Can typically only be iterated over once
  • Is not as useful for updating back to the database

DataSet

DataSet is a disconnected orient architecture that means there is no need of active connections during work with datasets and it is a collection of DataTables and relations between tables. It is used to hold multiple tables with data. You can select data form tables, create views based on table and ask child rows over relations. Also DataSet provides you with rich features like saving data as XML and loading XML data.

protected void BindGridview()

{

SqlConnection conn = new SqlConnection(“Data Source=abc;Integrated Security=true;Initial Catalog=Test”);

conn.Open();

SqlCommand cmd = new SqlCommand(“Select UserName, First Name,LastName,Location FROM Users”, conn);

SqlDataAdapter sda = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

da.Fill(ds);

gvUserInfo.DataSource = ds;

gvUserInfo.DataBind();

}

DataAdapter

DataAdapter will acts as a Bridge between DataSet and database. This DataAdapter object is used to read the data from database and bind that data to dataset. DataAdapter is a disconnected oriented architecture. Check below sample code to see how to use DataAdapter in code:

protected void BindGridview()

{

SqlConnection con = new SqlConnection(“Data Source=abc;Integrated Security=true;Initial Catalog=Test”);

conn.Open();

SqlCommand cmd = new SqlCommand(“Select UserName, First Name,LastName,Location FROM Users”, conn);

SqlDataAdapter sda = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

da.Fill(ds);

gvUserInfo.DataSource = ds;

gvUserInfo.DataBind();

}

  • Lets you close the connection as soon it’s done loading data, and may even close it for you automatically
  • All of the results are available in memory
  • You can iterate over it as many times as you need, or even look up a specific record by index
  • Has some built-in faculties for updating back to the database.

DataTable

DataTable represents a single table in the database. It has rows and columns. There is no much difference between dataset and datatable, dataset is simply the collection of datatables.

protected void BindGridview()

{

SqlConnection con = new SqlConnection(“Data Source=abc;Integrated Security=true;Initial Catalog=Test”);

conn.Open();

SqlCommand cmd = new SqlCommand(“Select UserName, First Name,LastName,Location FROM Users”, conn);

SqlDataAdapter sda = new SqlDataAdapter(cmd);

DataTable dt = new DataTable();

da.Fill(dt);

gridview1.DataSource = dt;

gvidview1.DataBind();

}

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