database

How to integrate access control with my ORM in a .net windows form application?

I am developing a general database query tools, a .Net 3.5 Windows Form application. In order to make the presentation layer is independent of the database layer. I use an ORM framework, XPO from DevExpress. But, I have no access control function built in. I surfed Internet and I found in WCF Data Services, there is an interesting conce...

Which key value store is the most promising/stable?

I'm looking to start using a key/value store for some side projects (mostly as a learning experience), but so many have popped up in the recent past that I've got no idea where to begin. Just listing from memory, I can think of: CouchDB MongoDB Riak Redis Tokyo Cabinet Berkeley DB Cassandra MemcacheDB And I'm sure that there are mor...

Data integrity when updating/incrementing values in Rails

I am working on an application in which one module accesses a log (an ActiveRecord model) to increment various values at several points of the execution. The problem is that the script is likely to take several seconds, and other instances of the same script is likely to run at the same time. What I'm seeing is that while the script fin...

How do I interpret precision and scale of a number in a database?

I have the following column specified in a database: decimal(5,2) How does one interpret this? According to the properties on the column as viewed in SQL Server Management studio I can see that it means: decimal(Numeric precision, Numeric scale). What do precision and scale mean in real terms? It would be easy to interpret this as a ...

SQLAlchemy - Problem with an association table and dates in primary join

Hi, I am working on defining my mapping with SQLAlchemy and I am pretty much done except one thing. I have a 'resource' object and an association table 'relation' with several properties and a relationship between 2 resources. What I have been trying to do almost successfully so far, is to provide on the resource object 2 properties: pa...

Why does known valid Django model instance fail is_valid() after retrieval from database?

We have a Django Model, ToolDataset, and a ModelForm, ToolForm. In the Model each instance, or database row, is referred to as a dataset, and the primary key is called the dataset_id. First time through, the user fills out an unbound form and submits it. Conceptually, this is the view code that is used to validate, save and analyze the d...

A GUI which creates and uses a database and installes easily.

I want to create a GUI with C++ (QT4). The GUI should work on Windows and should be able to create a database use the database created by it (I should use an existing DBMS, in order not to worry for querries) database should be specific to the GUI, other sowftwares should not be able to use that database (the database may be for examp...

Fantasy names database

I am building a demo dataset for my webapp. I would like thousands of "real looking" names. They should not be names of famous people or fiction heroes or names that will evoke associations. They should all have various and different sounding but realistic male and female names and surnames. Birth dates and other data can be randomly ge...

How do I store (and sort) vague date ranges?

Hi, I have a database which needs to store year ranges (such as lifespan) which in some instances aren't very specific. For example, as well as the usual '1960', we have 'c. 1960' for "around 1960", and 1960s for in the decade 1960, as well as 'nd' for no date which is distinctly different from NULL which would be until present. What wo...

MySQL: Loop through databases and run a stored procedure on it

Hi, I'm very new to MySQL and I have a stored procedure that I'd like to add to several legacy databases. I'm using SQLyog and I would like to loop through each database on the connection and if it matches 'application_%' (databases are called application_clientName, there are dozens) to run the stored procedure. A script I can save a...

Can you explain what's association relation in database?

I thought it was alias for simple foreign key relation,but seems not. Can you take MySQL as an example what is association relation? I guess it means many2many relation,is that true? ...

Database connectivity within an iPhone application.

Hello, I was wondering if there were any good sources or documents that could explain to me how I can cannot to a PostgreSQL database from within my iPhone application. Also, if they could go beyond just connecting, and explain how to use PL/SQL and Object Persistence within the Objective C iPhone SDK framework as well, that would be a...

How can this SQL query code be broken/exploited by user input?

Possible Duplicate: Can I protect against SQL Injection by escaping single-quote and surrounding user input with single-quotes? We have a legacy app that doesn't do queries using positional parameters, and there's SQL everywhere. It was decided (before I started here) that since user input can contain apostrophes, every string...

DBUnit automatic dataset generation

I have seen a couple of question regarding creating datasets in DbUnit here on StackOverflow, but all of them were regarding export data from existing tables. My question is, can DBUnit create some dummy dataset basing on my database schema? I don't care whether the strings would be like "ZDSFFDSDGF" and BLOBS would be just garbage. I j...

mysql: Optimizing query w/ mixed-ascendency ORDER BY

I have a large table (~1M rows now, soon ~10M) that has two ranked columns (in addition to the regular data): avg_visited, a float 0-1 representing a %age popularity; higher is better alexa_rank, an integer 1-N giving an a priori ranking The a priori ranking is from external sources so can't be changed. Many rows have no popularity y...

Difference between JDBC Driver type numbers

I am very new to Java, when i was going through the JDBC section, i noticed that JDBC has different Drivers like Type 1 Driver Type 2 Driver etc.. to Type 4 Why did they get the name like Type 1, Type 2 etc.., Is there any logic? ...

How to remove or avoid inserting column headers when importing a separated value file into a database using PHP?

I have semicolon-separated .dat file and I want to read that file and store its contents into a database. Structure of .dat file: PARTYID;PARTYCODE;CONNECTION 256;319;234 879;435;135 SQL to import the .dat file: $sql_qry = "INSERT INTO DatTable (PARTYID,PARTYCODE,CONNECTIONID) VALUES ('$data[0]','$data[1]','$...

Database of common name aliases / nicknames of people

I'm involved with a SQL / .NET project that will be searching through a list of names. I'm looking for a way to return some results on similar first names of people. If searching for "Tom" the results would include Thom, Thomas, etc. It is not important whether this be a file or a web service. Example Design: Table "Names" has Name and ...

Oracle sequence caching

I am trying to implement a sequence in an Oracle database to act as a surrogate key creator for a table. For performance reasons, I want this sequence to be cached. I have read that there are potential pitfalls when using cached sequences since rollbacks and instance failures will result in missed values. This got me to thinking. Let...

Question about join/update/insert sql query

I am working on making a new sqlite database. Obviously for a number of reasons, structure and organization is important. I have an existing database that is everything that I need, except for one column. So I duplicated the original db, and would like to just swap out that one column with new data from a different column in a different...