Aliases for Multi-Column Sort
What are some other names for a multi-column sort? ...
database
How to use database as backup/failover in hibernate?
Hi, My application is based on the hibernate to fetched data from a mysql server. This mysql server is replicated to another mysql server instance. Today, I got a downtime as the primary database server was gone down without any notice. To avoid any future accidental problem, I am planing to add a functionality that will enable system t...
database: summarizing data which expires
I'm struggling to find an efficient and flexible representation for my data. We have a many-to-many relationship between two entities which have arbitrary lifetimes. Let's call these Voter and Candidate. Each relationship has a measurement which we'd like to summarize in various ways. These are timestamped and are guaranteed to be within...
Database encryption or application level encryption?
When you need to store sensitive data such as CCs or SSNs, do you: 1) Build your own encryption routine within the application, define a secret key somewhere in a config file, and then manually encrypt/decrypt data going to the database. 2) Push all the problem to the database, using the built in DB capabilities (I think most vendors c...
How to empty foxpro db table ?
How can i empty the whole foxpro db table using any trigger or stored procedure ...
Database - Query
I have two Database (eg. two .mdb file). both have same name, same table and same field. the difference is one is old and other is updated copy of .mdb file. i want to copy only new records from the updated copy of the .mdb to the older one. is there any way other than iterate trough all the records and compare and filter only newer one?...
ruby on rails rake db:migrate error
hi , i'm starting to learn ruby on rails using this guide : getting_started , i created my project and database but when i run rake db:migrate i get this error: @mona-Extensa-5230:~/rubyDev/Sites/blog# rake db:migrate (in /home/mona/rubyDev/Sites/blog) == CreatePosts: migrating =================================================...
Radio button click doesn't register inside ListView
Hi! I have a radiobutton group in Android that I populate with data from a database. To get the data to show next to each radiobutton I have used the ListAdapter: String[] columns = new String[] {DataHelper.KEY_WORD, DataHelper.KEY_ALT1 , DataHelper.KEY_ALT2 ,DataHelper.KEY_ALT3 ,DataHelper.KEY_ALT4 }; // the XML defined vi...
how to fetch random numbers of rows from mysql database?
I have around 300 records in some table in mysql database. And I have a requirement to fetch 40 random records with one query. How to write the query? need help thanks. ...
how to track change in datagrid to update database?
If i bind datagrid to a collection, how can i track changes, e.g. object deleted/modified, so that I know how to update the database, do I have to manually handle those event to record which object is deleted, which is modified? is there a better solution? ...
DB Design for Schedule
I'm creating a web application wherein users should be able to specify their weekly schedule. Here's my DB model for that: id user_id day from to day is an enum of 0-6 (0 for Sunday, 1 for Monday, and so on). from and to represent minutes from midnight. So, 0 means midnight, 1 means 12:01am, 2 means 12:02am, etc. Is this a good desig...
Creating a simple multi-user desktop application
I'm working on a simple mark management system for a school department (let's assume it's the Maths department). They want a simple system for users to enter marks for each student as they progress, entering marks for each term, getting yearly averages, sorting by teacher, etc. Speaking to the person in-charge of the department, he said...
Is there in-memory SQL database supporting replication/clustering?
Free and stable is the winner. My plan is quite trivial - just put all the data in memory and use the cluster without changing the application code. Then, for persistence, I could just dump the data from nodes in a regular disk-access database. The only thing is, that since I demand in-memory storage, there is no possibility of full da...
Introducing a new table between parent and child tables
If I have a parent and a child table filled with data, is it trivial to add a new table between them? For example, before introduction the relationship is: Parent -> Child Then: Parent -> New Table -> Child In this case I'm referring to SQLite3 so a Child in this schema has a Foreign Key which matches the Primary Key of the Parent T...
GAE organizing data structure problem
Ok. I'm working with GAE. And i want create something like this: I have types "group" "topic" "tag": each "group" can have as many "topics" as needed each "topic" can have as many "tags" as needed each "group" can have as many "tags" as needed it's something like circle. right now i have something like this: class TopicGroup(db.Mo...
qt designer and data bound controls ?
can I use QT Designer 4 to create / design tables or other controls with automatic binding to database connections? Or must I write specific code for that in my application? (i'm using python 2.5 with pyqt 4.8 on Windows xp, if it matters) Thanks. ...
Distributed LSH (locality sensitive hashing)
I want to build a large scalable database with millions of high dimensional vectors using LSH. Since I have to hold all the data in ram for fast querying, the data must be distributed onto multiple servers to hold all the objects. A naïve approach would be to spread all objects to different servers and send one query to every server. Th...
score board php/Mysql
I have a database which stores the username score timestamp (i use the Unix time() function) Whenever user does a specific task the score is increased and corresponding time stamp updated. I want to retrieve the score board with usernames and scores.Ordering the scores with respect to the scores is easy (iam using ORDER BY score...
Ways to give a SQLite a variable name
I am tracking changes made to a levels in a game. The way I currently track changes is in a sqlite database. Each level is supposed to have its own database, as just one database for all the levels would provide complications when adding and deleting levels. So for each level, I want a database that has the same name as that level. SO th...
Eloquera DB on Windows Phone 7 / WP7?
Has anyone tried using Eloquera DB on WP7? Besides the question of whether it actually works under WP7, how is the performance (if it actually works)? Are there alrernative object-based DBs that anyone can recommend for use with WP7 applications? ...