database-design

How to add user customized data to database?

I am trying to design a sqlite database that will store notes. Each of these notes will have common fields like title, due date, details, priority, and completed. In addition though, I would like to add data for more specialized notes like price for shopping list items and author/publisher data for books. I also want to have a few gen...

SQL Server many-to-many design recommendation

I have a SQL Server database with two table : Users and Achievements. My users can have multiple achievements so it a many-to-many relation. At school we learned to create an associative table for that sort of relation. That mean creating a table with a UserID and an AchivementID. But if I have 500 users and 50 achievements that could ...

Error: Too Many Arguments Specified when Inserting Values from ASP.NET to SQL Server

Good Afternoon All, I have a wizard control that contains 20 textboxes for part numbers and another 20 for quantities. I want the part numbers and quantities loaded into the following table: USE [Diel_inventory] GO /****** Object: Table [dbo].[QUOTEDETAILPARTS] Script Date: 05/09/2010 16:26:54 ******/ SET ANSI_NULLS ON GO SET QUOT...

Feeding a Drill Down Menu with categories, subcategories and subSubcategories from a database

Hi everyone, I have a Drill Down menu and I want to have it gets its elements from a database, I am using php and MySQL and the table (categories) looks like this : http://yfrog.com/jctablehsj I can't figure out how I can extract these information in a way I could put it inside the Drill Down Menu ! I found the recursive method (with ...

Determining Best Table Structure for MySQL Performance

I'm working on a browser-based RPG for one of my websites, and right now I'm trying to determine the best way to organize my SQL tables for performance and maintenance. Here's my question: Does the number of columns in an SQL table affect the speed in which it can be queried? I am not a newbie when it comes to PHP or MySQL. I used to ...

Is the set of data always normalized in one form or the other in Databases

Suppose I have a set of data, given the data and the relation schemas can I assume that the set of data is normalized in one form or the other. In my opinion raw data given, has to be normalized into some form. However a discussion with a friend has led to ask me this question here. To expound more on the question, I would say given a s...

Active Record/ORM vs Normal Forms?

Hello, I've been playing around with Active Record a bit, and I have noticed that A.C./ORM always uses the following database model when creating a one-to-one relationship Person id | country_id | name | ... Country id | tld | name | ... No I wondered, isn't this a violiation of the third Normal Form? This clearly states "...

When using a HiLo ID generation strategy, what types should be used to hold Ids?

I'm asking this from a c#/NHibnernate perspective, but it's generally applicable. The concern is that the HiLo strategy goes though id's pretty quickly, and for example a low record-count table (Such as Users) is sharing from the same set of id's as a high record-count table (Such as comments). So you can potentially get to high number...

table design for storing large number of rows

I am trying to store in a postgresql database some unique identifiers along with the site they have been seen on. I can't really decide which of the following 3 option to choose in order to be faster and easy maintainable. The table would have to provide the following information: the unique identifier which unfortunately it's text the...

Modeling many-to-one with constraints?

I'm attempting to create a database model for movie classifications, where each movie could have a single classification from each of one of multiple rating systems (e.g. BBFC, MPAA). This is the current design, with all implied PKs and FKs: TABLE Movie ( MovieId INT -- PK ) TABLE ClassificationSystem ( ClassificationSystem...

Foreign keys and NULL in mySQL

Hi everyone, Can I have a column in my values table (value) referenced as a foreign key to knownValues table, and let it be NULL whenever needed, like in the example: Table: values product type value freevalue 0 1 NULL 100 1 2 NULL 25 3 3 1 NULL Tab...

How to implement Auto_Increment per User, on the same table?

I would like to have multiple users that share the same tables in the database, but have one auto_increment value per user. I will use an embedded database, JavaDB and as what I know it doesn't support this functionality. How can I implement it? Should I implement a trigger on inserts that lookup the users last inserted row, and then ad...

Best way to track impressions/clicks in a bespoke advertisement system?

I've been asked to create a bespoke advertisement system despite suggesting open source alternatives such as OpenX and DoubleClick for Publishers (the former Google Ad Manager). I've got the basics of the system set up, i.e. uploading creatives, creating positions and a mechanism to place creatives within positions; however, the area I'...

Database Designer for Visual Studio?

I am working on a database project and the entire team is working within Visual Studio. I created a database project, and I suppose I was hoping that I could utilize UML diagramming (or something along the lines of MySQL Workbench) so that I could "design" my database, and then auto-generate scripts. Unfortunately, at least from my cur...

Database per application VS One big database for all applications

Hello, I'm designing a few applications that will share 2 or 3 database tables and all of the other tables will be independent of each app. The shared databases contain mostly user information, and there might occur the case where other tables need to be shared, but that's my instinct speaking. I'm leaning over the one database for all...

related categories - database design

Hello! I'm looking for a little database design advice... I have a spreadsheet with a few columns in it. Column 1 being a list of categories and the rest being related categories(to the category in column 1). I'm trying to figure out what the best way to setup the tables would be... My thought so far is to have a table that just lists...

Help With Database Layout

Hello everyone, I am working on a site similar to Craigslist where users can make postings and sell items in different cities. One difference between my site and Craigslist will be you will be able to search by zip code instead of having all of the cities listed on the page. I already have the ZIP Code database that has all of the city,...

Simple database design and LINQ

I have very little experience designing databases, and now I want to create a very simple database that does the same thing I have previously had in xml. Here's the xml: <services> <service type="writing"> <small>125</small> <medium>100</medium> <large>60</large> <xlarge>30</xlarge> </service> <service type="analys...

Entity framework and database logic.

Hi all, i have a question that's being around for several years. As all you know entity framework is an ORM tool that tries to model the database to an object oriented access model. All the samples I've seen are quering directly to the database tables. So, which is the role of the views in the database now?. The views were used to model...

Get info from multiple files, match it and then display to end user, what is fastest?

Hi, I need to build a website where we display data that is refreshed every 5minutes in a text file with a | separator. I currently use Java to do this. What I do now: I grab the textfile for every request through the website and process it and then display the data to the end user, this works fine, since Java can go through like 5000 ...