establishing connection using ado .net

Question

Why do we use  using keyword while establishing connection  in C#.?   Ex- using(connection con=new connection()) {  // some ado .net code to access or insert/data . }

Amit Kumar Singh · Answer

hey,   1. The reason for the "using" statement is to ensure that the object is disposed as soon as it goes out of scope, and it doesn't require explicit code to ensure that this happens.   2. The using will take care of it for you. Under the hood, SqlConnection.Dispose() calls the SqlConnection.Close() method, and SqlCommand.Dispose() calls SqlCommand.Close()   a using statement is syntactic sugar for a try ... finally that disposes the IDisposable object in the finally .   3. The using statement will call conn.Close() automatically due to the using statement (using ( SqlConnection conn = new SqlConnection(connString) ) and the same for a SqlDataReader object.   And also if any exception occurs it will close the connection automatically.   for Example : using ( MyResource myRes = new MyResource ()) { myRes . DoSomething (); } OR { // limits scope of myRes MyResource myRes = new MyResource ();
try { myRes . DoSomething (); } finally { if ( myRes != null ) (( IDisposable ) myRes ). Dispose (); } }
For more reference refer this link 1.http://www.c-sharpcorner.com/uploadfile/manas1/usage-and-importance-of-using-in-c-sharp472/

Srinivasan Ramamoorthi · Answer

The using statement defines a scope at the end of which an object will be disposed. The using directive creates an alias for a namespace or imports types defined in other namespaces.   Refer the link for details https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/using

Vinitha T · Answer

If an Exception occurs while creating objects or calling methods / properties, the Using statement call the Dispose() method automatically.
Dispose() method belongs to IDisposable interface which hepls to implement Garbage collection.
Using statement hepls to call Dispose() on the object in proper way.
We instantiate an object in Using statement. At the end of statement, it calls Dispose() automatically.
There is a chance for having exception in database operation, so we need to call Close() explicitly. If we use Using statement, then there is no need for calling Close() explicitly it closes the connection automatically.

Khaja Moizuddin · Answer

As you are using connection class object you can use usingConnection or you can first set the namespace like using system.data.sqlclient;
And within a class you can use
Sqlconnection conn= new sqlconnection ();
https://msdn.microsoft.com/en-us/library/ms971481.aspx#adonetbest_topic5
Refer this blog for usingConnection.

Salman Beg · Answer

If we use using keyword then it will automatically dispose the Connection after execution complted.so there is no need to dispose your connection externally.Thanks.