I would like to learn database modelling. I don't have an exposure to database modelling yet, though I worked on Database Application development on Oracle DB (I know relationship between business model and database model and how a product database supports the business model).
It would be so kind of you, if you can direct me on the right path to learn database modelling from the scratch.
My approach to this would be -
My current level of understanding on basics of Data Modelling.
Learning the basics and refresh the known items.
Learning the intermediate and building sample data model and experience the challenge.
To follow the above mentioned approach, I require the following details. -
A tool to measure my current level of understanding on (basics of) Data Modelling.
A good place to start learning the database modelling. (A website / A recommended book / A good video tutorial(free is the best option!))
A decent data model exercise probably with answers / suggestions so that I can realise my effort.
Please let me know if either the approach or details are not up to the level for a starter, and guide me on the same.
Thanks.
I suggest you to take this course at Stanford (free, online): http://db.class2go.stanford.edu
Similar course is available at coursera (free, online): https://www.coursera.org/course/db
You did not mention, for what purpose you would like to learn database modelling. If data warehousing is is also on your list of skills, you should consider the following books:
Agile Data Warehouse Design: Collaborative Dimensional Modeling, from Whiteboard to Star Schema
The Data Warehouse Toolkit: The Complete Guide to Dimensional Modeling (Second Edition)
Star Schema The Complete Reference
This is a good site to get you started
After you get a fundamental overview of databases, I recommend going over to SQL Zoo to get your hands dirty:
http://sqlzoo.net/
Related
I am beginning in UML and software analyse and i do not understand how UML and diagrams can influence coding and software architecture while we can directly build the code and its data base without diagrams.
I read lot of tutorials abouat the subject but not enough to understand the utility of UML in coding.
I understand everey diagram and its role. That is not my problem but i do not yet understand their roles after the analyse and design phase.
So what is the role of UML in coding phase of a software ?
Thank you.
The comment by #xmojmr already puts it right. UML creates a model (hence the M in UML) of a system. A model reduces information of a system to a level so it is a) manageable and b) complete. Human brains are not computers and you need a means of communication what the system is all about. You can do that as pure code, as paper document and as UML model. A combination of all is not uncommon. As long as you have tiny systems you can live with pur code and tools like Doxygen. But once it starts getting complex you need some handles. UML offers these to end users, architects, testers, developers, managers, etc. Along with UML you will also need a methodology. UML delivers the syntax how to document a system. But you need some structure above to write a nice novel.
UML-based models play an essential role for coding/implementing a software system in model-based (or model-driven) development. The basic idea is that you start making a model of your problem domain (the domain model), then you derive from it a platform-independent design model, which can be transformed into platform-specific implementation models (e.g. for Java- or C#-based platforms) that are finally encoded in the target languages.
The most prominent part of model-based development is the encoding of model classes (forming the model layer in an MVC architecture for apps) based on a data model (a UML class model) that has been derived from an information design model, which was obtained from a domain information model (where all these information/data models are UML class models).
You can find an instructive example of model-based development in my tutorial book Engineering Front-End Web Apps with Plain JavaScript.
This one is in my point of view a duplicate of that other question. It can't be flagged because there is no accepted answer. The related question on meta stackexchange does not provide a clear solution to that situation.
I think my personal answer was relevant and is applicable to the current question.
To be synthetic, Martin Fowler considers current uses of UML. I think he describe the current practices. Perhaps should these evolve ?
Perhaps would the initial question be the right place to discuss ?
I am a beginner but know the basics and am peering into more advanced data mining and stored procedure routines. I have learned small concepts that mimic C# Design Patterns such as looping structures but have not seen much (on the web) about SQL Design Patterns.
I ask because I ran across this book http://www.amazon.com/SQL-Design-Patterns-Programming-Focus/dp/0977671542 but have also always been told that you will find better information on sites like Stack than in a book.
I've been told that for programming professionals Design Patterns are a must. Is this also the case for SQL programmers?
*(Wasn't sure if this belonged on Meta or not. It's not a question about the site but is a general discussion question)
Design patterns for SQL are very useful as well. Is it any good to gather data if you do not store it properly and retrieve it back to make useful decisions?
I have found Joe Celco's books very useful on database design patterns. http://www.amazon.com/Joe-Celko/e/B000ARBFVQ
Of course you should read books. In the first place they tend to be written by people recognized for their expertise (not just anyone who happens to log into the site) so the information is likelier to start out as more accurate. Then they have editors who help make the presentation of the information better. Finally a good book should discuss in more depth than an SO post can do and thus you will get information at a deeper level than just the code to fix your current problem. This means your understanding will grow and you will know why you would do X vice Y and be able to expand that understanding to new problems.
DBAs who don't read books probably don't understand the internals of how the database works very well and are likely to be less effective than those who do read in depth about their profession.
A book I recommend is:
http://www.amazon.com/SQL-Antipatterns-Programming-Pragmatic-Programmers/dp/1934356557/ref=pd_sim_b_1
Also books on performance tuning are critical to read if you want to use good patterns in your SQL. A huge number of performance problems are caused by badly designed SQL. YOu should know what works well and what doesn't. Those tend to be databse backend specific, so look for ones realting to the type of databases you support.
I'm not sure if this is the right place to ask this question but here goes.
I'm currently looking into some different techniques to model a business proces. I need to find a suitable option for my company which develops all kind of web applications.
What i have found so far:
UML, specificly the activity diagrams
Flow charts
Windows workflow foundation
Business process modeling
I had a dive into the world of workflows but it's mainly about automating a process of a company and thats not what I'm looking for. My focus is on software and the process within.
If anyone else knows some other technique or can tell me the advantages or disadvanteges of the techniques I allready found that would be much appreciated because I'm a little stuck right now.
Right now BPMN (Business Process Modeling Notation) and UML activity diagrams are the two most popular options for that.
I think of BPMN as the right choice when you are modeling the business aspects of the organization and move to Activity Diagrams as soon as you drill down to the technical design of the software system (as a core component of the UML language, activity diagrams are a better fit when having to combine workflow information with other views of the system, expressed also as UML diagrams like class diagrams or sequence diagrams).
Note that now a UML profile for BPMN is being created which means that you will be able to mix BPMN and UML diagrams in the same project
I suggest you consider ISO/IEC 24744. It will give you a very different perspective, since it does not use the ubiquitous "organisation as machine" metaphor, going for a more opportunistic, people-oriented viewpoint.
In other words, ISO/IEC 24744 does not represent a business process as a workflow where the process to follow is the driver. Instead, a business process is represented through the work products that are involved and the people that act upon them. The process performed plays an important but secondary role.
If you are interested in why this is so, or what the advantages are, let me know and I'll be happy to elaborate.
I think you are asking about transforming your business requirements/rules into technical requirements and then into a design? After that you will implement this design into code.
Am not sure if this is what you are asking about..
I am starting to delve into the realm of ORMs, particularly NHibernate in developing .NET data-aware applications. I must say that the learning curve is pretty steep and that a lot of things should be noted. Apparently, it actually changes the way you do data-aware applications, manner of coding, development and just about everything.
Anyway, I want to ask if you do set some parameters when deciding to USE or NOT TO USE ORMs in your applications? How do you decide then the approach that one needs to make it valuable to your organization?
The organization which I work for now apparently has made a lot of SQL and Data Access thing running through back end and I must say that these class/methods/procedures have successfully performed their tasks of providing the data which is needed and when it is needed. I think it would be a tremendous effort just to map some of this into ORM and derive the same business value that the company has for the last few years.
Nevertheless, I know that ORM paves the way for applications to talk with database servers, if properly implemented. I must admit that I am at a learning stage and that I would possibly need all the help, resources and the guidance to make this transition. I was also thinking of buying the book from Manning but I feel that with so much changes to NHibernate, the book may be a bit outdated. Perhaps waiting for the Packt book on NHibernate (release on May 2010??) would help me better get up and running.
Kindly share your thoughts. By the way, if you could also point me in a small sample web app which uses NHibernate + Visual Web Developer 2008 Express and SQL Server, that would be highly appreciated.
Thanks.
For me, the short of it is the following:
If you don't use an established ORM, and you develop correctly (meaning you refactor out duplication and look to simplify where you can), you'll wind up building your own ORM through the evolution of your data access layer.
The question then becomes:
"Do I want my developers spending time learning the idiosyncrasies of my home-grown ORM or learning those of a well-documented and well-tested ORM?"
Furthermore:
"If I'm hiring a new developer, wouldn't it be nicer to bring in a developer that knows the established ORM tool we're using rather than having to train someone up on this thing I built?"
I use NHibernate, particularly Fluent - and it's great; if given the choice, I wouldn't develop on an RDBMS any other way.
To be successful with an ORM you must make sure to normalize correctly, and use the database for it's designed purpose, storing data.
I don't use an orm when:
I don't use a relation database (Relational databases are not the best choice of database for every application)
The database is has a very small amount of tables. (I might need less code without an orm)
I use a very simple database that can map to code with simple naming
conventions. (Mapping to dumb DTO classes and all queries like select * from tablename where id=#id)
Learning a good orm is worth the time and effort, it will save you writing a lot of code when you use relational databases a lot.
You can find example apps/tutorials/video's about NHibernate on with stackoverflow search. There is another book in progress by manning, maybe it's possible to read it with the early access program.
Would some one suggest me the best method to start learning the fundas of programming.
I would be involved in SQL and SAS related technologies involving databases.
Please advice
SQL is an easier one to tackle. You can download a small database (mysql or oracle express) and begin working. Test and play and read until you get the hang of it. There are many articles available to give guidance. Just Google.
SAS on the other hand is a bit more difficult. You can't get your hands on the software unless your employer has a copy or you purchase a user copy from your university or from SAS. I would suggest taking a class from SAS. They offer SAS Essentials 1 for beginners. Great class, not cheap.
My best advice on learning to program: Pick a project and start working on it. Things will make a lot more sense when you try to use them. You don't have to finish even. Don't worry about the end result. You'll learn through the process.
The best advice I can give you is to get books on the subject and maybe try find somebody in your area you can learn from or work with to gain some knowledge. Otherwise find articles and blogs relating to SQL and SAS.
Good luck!
both sql and sas are not good for learning programming fundamentals, because they are not typical programming languages. Learn C# or Java for system development, or Python or Ruby for scripting. Most undergraduate programming courses will also include some kind of functional programming languages.
once you have some fundamentals under your belt, sql itself can be learned in a very short time. in the class I took on database systems, the professor gave only two one-hour lectures on sql.
sas has a steep learning curve, because it is a system, not a language. In terms of languages, in fact, some might say that it has 30 or more different "languages" in it.