SQL Server- Union and Union All

A good link which explains this topic with simple example;

Comments

Post a Comment

Popular posts from this blog

Lazy Loading in Entity Framework

ets write a simple query to fetch the top 20 employees from the Northwind database and count the number of orders placed by each employee. NORTHWNDEntities context = new NORTHWNDEntities(); var employees = context.Employees.Take(20).ToList(); foreach (Employee employee in employees) { Console.WriteLine("Total number of order by employee : {0}", employee.Orders.Count); } We start off with creating the ObjectContext which is NORTHWNDEntities in our case. We filter the 20 employees using Take method on the employees entity collection. Then we loop over the individual employees and display the count of Orders to the console window. By default Entity Framework 4 enables the Lazy Loading feature. Because of this there are multiple hits to the database server. The initial query which filters the 20 employees is executed when we start iterating over the loop. And then for each employee a separate query i...
Read more

How Threading Works

Multithreading is managed internally by a thread scheduler, a function the CLR typically delegates to the operating system. A thread scheduler ensures all active threads are allocated appropriate execution time, and that threads that are waiting or blocked (for instance, on an exclusive lock or on user input) do not consume CPU time. On a single-processor computer, a thread scheduler performs time-slicing — rapidly switching execution between each of the active threads. Under Windows, a time-slice is typically in the tens-of-milliseconds region — much larger than the CPU overhead in actually switching context between one thread and another (which is typically in the few-microseconds region). On a multi-processor computer, multithreading is implemented with a mixture of time-slicing and genuine concurrency, where different threads run code simultaneously on different CPUs. It’s almost certain there will still be some time-slicing, because of the operating system’s need to service its o...
Read more

Interview Questions to Ask the Employer

It's your turn! As the interview comes to a close, one of the final questions you may be asked is "What can I answer for you?" Have interview questions of your own ready to ask. You aren't simply trying to get this job - you are also interviewing the employer to assess whether this company and the position are a good fit for you. Here are questions to ask the interviewer so you can ensure the company is a good match for your qualifications and interests. How would you describe the responsibilities of the position? How would you describe a typical week/day in this position? Is this a new position? If not, what did the previous employee go on to do? What is the company's management style? Who does this position report to? If I am offered the position, can I meet him/her? How many people work in this office/department? How much travel is expected? Is relocation a possibility? What is the typical work week? Is overtime expected? What are the prospects for growth and a...
Read more