Hello, I am trying to set up a normalised MySQL database containing the three following tables. The first table contains a list of items which can be described by various tags. The third table contains the various tags used to describe the items in the first table. The middle table relates the other two tables to each other. In each...
There has been a lot of talk about contra-revolutionary NoSQL databases like Cassandra, CouchDB, Hypertable, MongoDB, Project Voldemort, BigTable, and so many more. As far as I am concerned, the strongest pros are scalability, performance and simplicity. I am seriously considering to suggest using some non-relational db for our next pr...
I've recently been asked to rewrite a booking system that was not performing as well as a client would like. I've found the database schema / object mapping technique used to be quite unusual and was wondering if anyone else has come across anything similar. The old system used about 25 classes for things like customers, appointments ...
I have a mysql database that I am trying to migrate into another database. THey have different schema's and I have written a php script for each table of the old database in order to populate its data in to the new one. The script works just fine but the problem is that it does not move all the data. for example if I have a table and all...
So I am trying to design a database that will allow me to connect one product with multiple categories. This part I have figured. But what I am not able to resolve is the issue of holding different type of product details. For example, the product could be a book (in which case i would need metadata that refers to that book like isbn, ...
Looking for any suggestions or advise or even best practices. I have developed an online database using php and mysql. It allows companies to log complaints and resolutions etc. There is a user database for login and a cip database for logging the main data. 2 companies are trialing and testing the database. At the moment each compan...
I am having a hard time getting started with some way to visualize some data consisting largely of congressional members and their political affiliations. As such it is mostly text data and doesn't lend itself immediately to something like ManyEyes, Google Charts etc. More to the point, I have spreadsheets of data on senators and repres...
I hope I'm not being too long winded in this question, I just want to make sure that what I'm asking is completely clear (I think it's rather confusing :). I've got a database with a bunch of tables with all my foreign key constraints set up. Relations are sometimes several tables deep, and there are also cases where a child is related ...
Let's say I have some parameters such as a,b,c, and I need to store the test results by changing them. The thing is that the the number of parameters will be keep increasing, so I can't keep them as static column. For example : Test 1 : a = 10, b = 20, c = 1 Test 2 : a = 11, b = 21, c = 11 Test 3 : a = 11, b = 20, c = 1 ... Test 1001...
How would I design the tables for a matching system doing something like this: We have X products which can have Y properties. The number of properties can vary from product to product and two products doesn't have to have any similar properties. My number one goal is to take one product and find the most similar product. Normally I w...
I have a table with the columns: city, x, y I need to select the distance between all the cities without duplications the results should look like this city1,city2,distance but I shouldn't get city2,city1,distance ( since I already got the distance between those cities... what is the correct SQL query for that... thanks! ...
I have a structure of about 10 tables. This structure works great for data entry. However, I also need to preform complex and fast searches on that dataset. There are three approaches to this I can think of: Join all those tables in select. This is pretty slow and likely not a good approach. If it's relevant, database is Informix; I've...
Suppose I have the following tables in my database: Now all my queries depend on Company table. Is it a bad practice to give every other table a (redundant) relationships to the Company table to simplify my sql queries? Edit 1: Background is a usage problem with a framework. See http://stackoverflow.com/questions/3331310/django-limit...
There is the: put a FK to your parent method , i.e. each records points to it's parent Which is a hard for read actions but very easy to maintain And then there is a directory structure key 0001.0000.0000.0000 main branch 1 0001.0001.0000.0000 child of main branch one etc Which is super easy to read, but hard to maintain. Wha...
I'm trying to figure out how to create a "sandbox" area in my new Windows .NET/SQL Server application. Here's the requirements: Users must be able to enter their own data for things like date ranges and pricing Users must be able to run multiple scenarios against this pricing and date range data The data structures above will also be u...
Hi, Can someone please explain what is the main difference between SQL Server Compact Edition and SQL Server Express Edition? For what purpose I should use this or that one? Thanks ...
Hi, I am here to design a relational database schema that models polling and users. Each category can have one or many questions. Each user can participate only once at each category, and can poll (or not) exactly once on each question. Each poll is yes, no, or abstain (no vote). I have designed my schema with four tables: users, [u...
This is a more a philosophical question about Apple's design decisions than a question about Core Data. Why in the world is it useful to have a model system that is so difficult to prepopulate? What are the advantages? I know you can have your program generate the sqlite file and edit it manually, but as far as I can tell, you can't do ...
I have an outings table, which basically holds some information about an 'outing'. These outings then have crews, which have users (through crew_users) Just as a note, outings have many crews, so there's an outing_id in the crews table Now, I need to find the user's next outing, as in the first outing where outing.start_time > Time.n...
I'm having a server client database design which I'm unsure is Core Data suitable? I have a server database which will maintain the master copy of the data and their relationship. Each client application will have an empty client database with only relationship. Upon the start up of the client, it will request for data from the server...