Representing list of polymophic objects in db
Let's suppose I have a list of derived objects from some base:class Circle : public Shape; class Rectangle : public Shape;There is object, which has vector of Shape * as member variable:class Screen {...
View ArticleHow can I test a method which aggregates data from a database?
I'm developing the web Java application and come across the following issue:I'm using jUnit 4.5.Suppose that I have a method which aggregates data from a database for the rendering their to a markup....
View ArticleCombine union with distinct
Situation: I need distinct results from two tables, that both have duplicates. I would like to know if I should combine UNION and DISTINCT.Example 1 - Only use distinctSELECT DistinctValueFROM...
View ArticleShould I rebuild my read only database every time I launch my server?
I'm getting into web development, and I'm trying to get a grip on databases.In an app I want to make, there is a read only database that will be filled up with a large amount of data, which will be the...
View ArticleWhen should I implement authentication in a database?
I'm currently embarking on a MongoDB project (a simple user login system), and I notice that there is an option for authentication. Here is the server string, with the userinfo shown as optional...
View ArticleHow to avoid deadlock errors ...
Hi there everybody.I've posted in "Getting started with SQL Server" because I think this could be quite a "basic" problem, and I also hope to get some general hints on how to accomplish this sort of...
View ArticleCase Statement
I am trying to write a case statement essentially along this linecase when column a<> column b then 'incorrect'else 'correct'but it doesnot seem to work, can you not do column comparison in a...
View Articlemissing functions
I'm working through the 70-461 training kit at home and for some reason my install of SSMS doesn't have the functions 'CONCAT() or FORMAT() installed. There may be others but I'm only on page 47. My...
View ArticleNeed a guideline to install the appropriate version of SQL Server on Windows 8
Hi Everybody, I just started to learn database programming with C#, but i am facing problems over problems. Actually I'm running Windows 8 Pro, x64 Architecture. I tried installing SQL Server 2008...
View ArticleWhether to store all numbers or just their ranges in database for this...
I'm developing a (PHP MySQL) Web App which will sell dynamically generated real time cell phone numbers for cellular companies. A company will ask for, say, a thousand numbers and this app will check...
View ArticleDatabase design with performance issue and use of views
I am designing database for a school system. I am having to create a lot of tables and a lot of link tables to maintain a structure in the system. I am trying to maintain foreign integrity and trying...
View Articlewhat data storage method should I use?
I am currently writing a program and among other things need to store data. The program listens to two computers talking to each other in a known protocol (the program know what protocol it is,the...
View Articleyour sql server installation is either corrupt or has been tampered with...
Hello, Whenever i make an MVC 5 controller with views, using entity framework and try to run and compile the file i get the "your sql server installation is either corrupt or has been tampered with...
View ArticlePrepared statement alternatives for this middle-man program?
I have an program that is using a prepared statement to connect and write to a database working nicely, and now need to create a middle-man program to insert between this program and the database....
View ArticleHow to ensure the success of processes after a deadlock exception occurs?
No matter the programming language is and whatever the database is, the concept should be the same: I have 2 threads, each locking some database entities and inserting new data in database. Let's...
View ArticleSelect Statement
Given below are the queries with their output.Please help to know why the output is like this:query outputselect $ 1select count(*) 1select sum(1+2*3) 7selec max(1+2*3) 7
View ArticleUser 'guest' does not have permission to run DBCC
Good day to you. I try to attach a database mdf file to Microsoft SQL server 2014 on Amazon Elastic Computing Cloud, EC2, but fail with the following message, "User 'guest' does not have permission to...
View ArticleHow fo find installed features of 2012 SSMS
I previously installed 2012 Management Studio, it is working fine. How do I find out the installed features? I need to install SSMS on another PC but can't figure out which features to install.Thanks.
View ArticleStore result of stored procedure into a variable
I wrote a stored procedure that finds a number. I want to store the number it finds into a variable so i can use it within another procedure. I hope i'm being clear.Any help will be appreciated. Here...
View ArticleTempDB - 70GB (70GB free space) but cant shrink DB, restarted SQL - Service -...
Hello Guys i've got a little problem here... because of some year end jobs the tempdb has grown up to 70GB. But from the 70GB only 4MB are used... i tried to shrink it down to 5gb (was in the beginning...
View Article