ADO.NET

yes,we can connect two dataadapters to same datasource using single connection at same time.

There is a technology in ado.net 2.0 called MARS usinng Mars in connection string we can do it.

for eg:

cn.ConnectionString = "server=(local); database=employee; integrated security=sspi; MultipleActiveResultSets=True";

No its not at all possible.

There is a method called Execute Non Query. This method executes the Update, Delete etc. This does not return any rows but will give the number of rows affected.

yes this is possible

If we execute 2 select command either in stored procedure or in select command and then executereader method fired of command object. it return 2 tables in datareader.

like :

string str="Select * from a;select * from b";

cmd.commandtext=str;

dr=cmd.executereader();

Now it return 2 tables in datareader (dr).

// Summary:

// Executes a Transact-SQL statement against the connection and returns the number of rows affected.

// Returns:

// The number of rows affected.

// Summary:

Executes the query, and returns the first column of the first row in the result set returned by the query. Additional columns or rows are ignored.

// Returns:

The first column of the first row in the result set, or a null reference (Nothing in Visual Basic) if the result set is empty.

DataReader DataSet DataTable DataView DataAdapter

Answer: DataAdapter

DataSet ds=new DataSet();

SqlDataAdapter dap=new SqlDataAdapter(Select * from <tablename>,<connection1>);

dap.Fill(ds,"TableOne");

SqlDataAdapter dap1=new SqlDataAdapter(Select * from <tablename>,<connection1>);

dap1.Fill(ds,"tableTwo");

connection String - a string which contains address of the database we want to connect to.

Delegate is an important element of C# and is extensively used in every type of .NET application. A delegate is a class whose object (delegate object) can store a set of references to methods.

a. Update a dataset;

Dataset ds = new dataset();

SqlDataAdapter adp = new SqlDataAdapter(Query,connection);

Adp.fill(ds);

Again you can add/update Dataset as below

SqlDataAdapter adp1 = new SqlDataAdapter(Query1,connection);

Adp1.fill(ds);

b. Update database through dataset.

SqlCommandBuilder mySqlCommandBuilder = new SqlCommandBuilder(mySqlDataAdapter);

Foreach(datarow dr in ds.table[0].rows)

{

Dr[“column Name”] = “value”;

mySqlDataAdapter.Update(ds);

}

you can connect sql using oledbname space .

A Partial class is a class that can be split into two or more classes. This means that a class can be physically separated into other parts of the class within the same namespace. All the parts must use the partial keyword. All the other classes should also have the same access modifier. At the compile time, all the partial classes will be treated as a single class. Let us list some advantages of having partial classes.

DateReader is an forward only and read only cursor type if you are accessing data through DataRead it shows the data on the web form/control but you can not perform the paging feature on that record(because it's forward only type). Reader is best fit to show the Data (where no need to work on data)

DataAdapter is not only connect with the Databse(through Command object) it provide four types of command (InsertCommand, UpdateCommand, DeleteCommand, SelectCommand), It supports to the disconnected Architecture of .NET show we can populate the records to the DataSet. where as Dataadapter is best fit to work on data.

1) DataSet is disconnected object type. It uses XML to store data.

2) It fetches all data from the data source at a time

3) Modifications can be updated to the actual database

4) It will reduce the application performance.

No, each have its own functionality,

ex : for sql client , there is SqlConnection object

and for oledb client , there is OleDBConnection

It has no such feature.