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How to Execute SQL Statements: ADO.NET

We have learnt about ADO.NET object model. In that article we have created a SQL connection, open that connection and close that connection. To execute the SQL statements, we have to write them in between the open and close method of the above connection.

So to execute the SQL statement we have to, first create the connection, open that, write some code which will be executed and at the last execute it with ExecuteReader() method of SQLCommand class.

SqlCommand class is used to specify the Sql statement to be executed and the connection that need to be used. It can also be used to execute stored procedures. Following code will used to execute Sql statement in a command object:

SqlConnection connection = new SqlConnection();
connection.ConnectionString = "Data Source=(LocalDb)\v11.0; Initial Catalog=StockDb; Integrated Security=True";
SqlCommand command = new SqlCommand("select * from Groups", connection);
SqlDataReader dr = command.ExecuteReader();

In the above code, when SqlCommand object will create, an object of SqlDataReader have been also created. And it is initialized with the function ExecuteReader(). Now all the data can be accessed one by one through dr object, one by one.

When we check the dataReader object through the breakpoint then there are some rows, as shown in following image:

Execute SQL Statement in ADO.NET

See also: Parameterized Sql Queries


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Memory representation of Linked List

             In memory the linked list is stored in scattered cells (locations).The memory for each node is allocated dynamically means as and when required. So the Linked List can increase as per the user wish and the size is not fixed, it can vary.

               Suppose first node of linked list is allocated with an address 1008. Its graphical representation looks like the figure shown below:

      Suppose next node is allocated at an address 506, so the list becomes,

  Suppose next node is allocated with an address with an address 10,s the list become,

The other way to represent the linked list is as shown below:

 In the above representation the data stored in the linked list is “INDIA”, the information part of each node contains one character. The external pointer root points to first node’s address 1005. The link part of the node containing information I contains 1007, the address of next node. The last node …