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Closed 11 years ago.
Do you know where I can find some practice SQL problems where I can write select statements?
SQL exercises or you can create a test table with fake data and manipulate that. Personally, I learn better with hands-on activity, by playing with the SELECT statements myself before even practicing an online guide. However, not everyone is the same.
Here are a few other links to check out:
SQLCourse - Interactive for beginners.
SQLCourse2 - It's awesome you can try and sharpen your skills.
Good luck.
Look the line of books by Celko, it has lots of examples and exercises.
You can find some here as well.
Try SQL Exercises.
Free and interactive.
Related
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Closed 10 years ago.
I would like to gather information about popular captcha scripts in one place.
Please write links to your favourite ones!
You can try
recaptcha
Textcaptcha
Picaptcha
Nucaptcha
Solvemedia etc..
But none of them are 100% useful and captchas seems out dated too because most of the spammers are humans. If you are using captcha the best solution is to create your own captcha with a unique algorithm.
http://recaptcha.net/ "recaptcha" for helping OCR-izing old books as a consequence in the worlds benefit
previously I used this one.But now I am creating my own like simple mathematical calculation or simple text.
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Closed 10 years ago.
Is there some kind of obvious database should I use for a Bulletin Board if I wanted to code one? I think I know how to code the rest of it, I know the imperative code to handle the logic, but I don't really know much about databases yet. This I can learn of course, I'm just wondering if there is something obvious I should know in the beginning, or an obvious place to start learning, besides sql 101. Also, please don't suggest reading the code of an open source project. I know that option is there. It's hard to decipher code in a language you don't understand really well.
You can check out this place they've got tons of database sample you can use to jumpstart a project http://www.databaseanswers.org/data_models/
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Closed 11 years ago.
I got following question on an interview:
Which SQL mechanisms allow user to browse tables sequentially?
Cursor is a good example - but I don't think you could really argue that Cursors are truely a part of SQL - rather they just tend to come bolted in with procedural languages used on database servers - like pl/SQL and T-SQL.
You could also make an argument for Recordsets, Dynasets, DataTables and DataViews, but those aren't part of SQL itself either.
They might be referring to ORDER BY with a sequential field on the table, but if so, they've not phrased their question very well...
Martin.
"CURSOR" might be the word that you should google for.
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Closed 10 years ago.
What is the best references/links,cheatsheets for the MDX language? Here are a few starters that I have collected. Please share yours :)
http://www.gumper.com/mdx.html
http://www.sqlserveranalysisservices.com/OLAPPapers/InventoryManagement%20in%20AS2005v2.htm
http://www.ssas-info.com/ssas-cheat-sheets/72-cheat-sheets/880-time-mdx-cheat-sheets
It's perhaps hard to look through if you don't know what you're looking for, but the Microsoft MDX Reference is actually very good if you know the name of the functions.
Obviously (or perhaps not that obviously) the MDX implementation differs between OLAP sources, and the Microsoft reference is tailored towards Analysis Services.
You'll find some MDX documentation (introduction and reference) at : http://www.iccube.com/support/documentation/mdx/index.html
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Closed 11 years ago.
I need to implement a Diff algorithm in VB.NET to find the changes between two different versions of a piece of text. I've had a scout around the web and have found a couple of different algorithms.
Does anybody here know of a 'best' algorithm that I could implement?
Well I've used the c# version on codeproject and its really good for what I wanted...
http://www.codeproject.com/KB/recipes/diffengine.aspx
You can probably get this translated into VB.net via an online converter if you can't do it yourself...
I like An O(ND) Difference Algorithm and Its Variations by Eugene Myers. I believe it's the algorithm that was used in GNU diff. For a good background see Wikipedia.
This is quite theoretical and you might wish to find source code, but I'm not aware of any in VB.
I don't know for sure if it's the best diff algorithms but you might want to check out those links that talks about SOCT4 and SOCT6
http://dev.libresource.org/home/doc/so6-user-manual/concepts
and also:
http://www.loria.fr/~molli/pmwiki/uploads/Main/so6group03.pdf
http://www.loria.fr/~molli/pmwiki/uploads/Main/diffalgo.pdf