ORA-00056 DDL lock on object 'string.string' is already held in an incompatible mode

Error Code
ORA-00056 

Description
DDL lock on object 'string.string' is already held in an incompatible mode

Cause
A possible cause of this error is that an attempt was made to acquire a DDL lock that is already locked.

Action
This happens if you attempt to drop a table that has parse locks on it.


reference

Consume ASMX web Service in ASP.NET 4.0

In last tutorial, we learn How to Create ASMX web Service in ASP.NET 4.0. This tutorial guides how to consume it.

• Add new aspx page. Right click on Website and click 'Add New Item'. A new window will appear.

• Select 'Web Form' and name it according to your choice.

• Create new object of web service by writing following code:

MyFirstWebService svc = new MyFirstWebService();

• Call web service method by writing following code:

svc.CallmyName("Waqas Ali");

How to Create ASMX web Service in ASP.NET 4.0

Asmx Web Services are easy and simple to Create and use. This tutorial guides you how to write a ASMX Web Service step by step. 

• Open Visual studio and create new Website. 
• Right Click on Website and Click on 'Add New Item'.

• A New Window will Open, select 'Web Service' , name it and click 'Add'.

• When you click 'Add' Button, new files ( with .asmx and .cs extensions ) will be added to Project.
• Visual Studio will add some code in it.
• A default Web Method named 'Helloworld' will also be added in it.

• You have created ASMX Web Service Successfully.
• Replace 'Helloworld' Web Method with following code.

• This is Custom Web Method we created for our ASMX Web Service.

In next tutorial, we will learn how to use this Web Service.

Advantages of Stored Procedure in Microsoft SQL Server

There are many advantages of using stored procedures in Microsoft SQL Server. These are :

1. Easier to maintain and troubleshoot as they are modular.
2. Stored procedures enable better tuning for performance.
3. While using stored procedures is much easier from a GUI end than building complex queries.
4. Stored procedures help in reducing network usage.
5. Stored procedures provide more scalability to an application.
6. Reusable and hence reduce code.
7. Stored procedures can be part of a separate layer which allows separating the concerns. Hence Database layer can be handled by separate developers proficient in database queries.

How to Code Efficient Transactions in Microsoft SQL Server

To Code efficient transactions in Microsoft SQL Server, We must take care of following things :

1. Don't allow input from users during a transaction.
2. Don't open transactions while browsing through data.
3. Keep the transaction as short as possible.
4. Use lower transaction isolation levels.
5. Access the least amount of data possible while in a transaction.