Search Results

Search found 432 results on 18 pages for 'beginners'.

Page 16/18 | < Previous Page | 12 13 14 15 16 17 18  | Next Page >

• F# passing an operator with arguments to a function

  - by dan

  Can you pass in an operation like "divide by 2" or "subtract 1" using just a partially applied operator, where "add 1" looks like this: List.map ((+) 1) [1..5];; //equals [2..6] // instead of having to write: List.map (fun x-> x+1) [1..5] What's happening is 1 is being applied to (+) as it's first argument, and the list item is being applied as the second argument. For addition and multiplication, this argument ordering doesn't matter. Suppose I want to subtract 1 from every element (this will probably be a common beginners mistake): List.map ((-) 1) [1..5];; //equals [0 .. -4], the opposite of what we wanted 1 is applied to the (-) as its first argument, so instead of (list_item - 1), I get (1 - list_item). I can rewrite it as adding negative one instead of subtracting positive one: List.map ((+) -1) [1..5];; List.map (fun x -> x-1) [1..5];; // this works too I'm looking for a more expressive way to write it, something like ((-) _ 1), where _ denotes a placeholder, like in the Arc language. This would cause 1 to be the second argument to -, so in List.map, it would evaluate to list_item - 1. So if you wanted to map divide by 2 to the list, you could write: List.map ((/) _ 2) [2;4;6] //not real syntax, but would equal [1;2;3] List.map (fun x -> x/2) [2;4;6] //real syntax equivalent of the above Can this be done or do I have to use (fun x -> x/2)? It seems that the closest we can get to the placeholder syntax is to use a lambda with a named argument.

  Read the article

• Entity Framework 4 / POCO - Where to start?

  - by Basiclife

  Hi, I've been programming for a while and have used LINQ-To-SQL and LINQ-To-Entities before (although when using entities it has been on a Entity/Table 1-1 relationship - ie not much different than L2SQL) I've been doing a lot of reading about Inversion of Control, Unit of Work, POCO and repository patterns and would like to use this methodology in my new applications. Where I'm struggling is finding a clear, concise beginners guide for EF4 which doesn't assume knowledge of EF1. The specific questions I need answered are: Code first / model first? Pros/cons in regards to EF4 (ie what happens if I do code first, change the code at a later date and need to regenerate my DB model - Does the data get preserved and transformed or dropped?) Assuming I'm going code-first (I'd like to see how EF4 converts that to a DB schema) how do I actually get started? Quite often I've seen articles with entity diagrams stating "So this is my entity model, now I'm going to ..." - Unfortunately, I'm unclear if they're created the model in the designer, saved it to generate code then stopped any further auto-code generation -or- They've coded (POCO)? classes and the somehow imported them into the deisgner view? I suppose what I really need is an understanding of where the "magic" comes from and how to add it myself if I'm not just generating an EF model directly from a DB. I'm aware the question is a little vague but I don't know what I don't know - So any input / correction / clarification appreciated. Needless to say, I don't expect anyone to sit here and teach me EF - I'd just like some good tutorials/forums/blogs/etc. for complete entity newbies Many thanks in advance

  Read the article

• making check boxes clickable once in javascript?

  - by OVERTONE

  Sorry but im an absolute noob with javascript. Ive made a form for a simple quiz but cant figure out how to make radio's only click once. I can select two or three buttons as my answer. i want to change this. <form name = "Beginners Quiz"> <p>Film speed refers to:</p> <p><input type="radio" name="Answer 1" id="Answer1" value = "a" onclick = "recordAnswer(1,this.value"/>How long it takes to develop film. <br/> <p><input type="radio" name="Answer 2" id="Answer2" value = "b" onclick = "recordAnswer(1,this.value"/>How fast film moves through film-transport system. <br/> <p><input type="radio" name="Answer 3" id="Answer3" value = "c" onclick = "recordAnswer(1,this.value"/> How sensitive the film is to light. <br/> <p><input type="radio" name="Answer 4" id="Answer4" value = "d" onclick = "recordAnswer(1,this.value"/> None of these makes sense. <br/> ive been rooting around w3shcools tutorials to no avail. can someone shed some light?

  Read the article

• Native functions throw UnsatisfiedLinkError in custom view, despite working in main activity

  - by Mark Ingram

  For some reason I can only call native functions from my main activity and not any custom views that I've created. Here is an example file (I followed a tutorial, but renamed the classes http://mindtherobot.com/blog/452/android-beginners-ndk-setup-step-by-step/) See the usage of the native function "getNewString". package com.example.native; import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.os.Bundle; import android.view.View; public class NativeTestActivity extends Activity { static { System.loadLibrary("nativeTest"); } private native String getNewString(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setContentView(new BitmapView(this)); String hello = getNewString(); // This line works fine new AlertDialog.Builder(this).setMessage(hello).show(); } } class BitmapView extends View { static { System.loadLibrary("nativeTest"); } private native String getNewString(); public BitmapView(Context context) { super(context); String hello = getNewString(); // This line throws the UnsatisfiedLinkError new AlertDialog.Builder(this.getContext()).setMessage(hello).show(); } } How can I call native functions in my custom views? I've built the application as an Android 2.2 app. I'm running the application on my HTC Desire. I have the latest SDK (9) and latest NDK (r5).

  Read the article

• Improve speed of a JOIN in MySQL

  - by ran2

  Dear all, I know there a similar threads around, but this is really the first time I realize that query speed might affect me - so it´s not that easy for me to really make the transfer from other folks problems. That being said I have using the following query successfully with smaller data, but if I use it on what are mildly large tables (about 120,000 records). I am waiting for hours. INSERT INTO anothertable (id,someint1,someint1,somevarchar1,somevarchar1) SELECT DISTINCT md.id,md.someint1,md.someint1,md.somevarchar1,pd.somevarchar1 from table1 AS md JOIN table2 AS pd ON (md.id = pd.id); Tables 1 and 2 contain about 120,000 records. The query has been running for almost 2 hours right now. Is this normal? Do I just have to wait. I really have no idea, but I am pretty sure that one could do it better since it´s my very first try. I read about indexing, but dont know yet what to index in my case? Thanks for any suggestions - feel free to point my to the very beginners guides ! best matt

  Read the article

• How to learn how to program?

  - by twinbornJoint

  I would like to know the best methods for learning to program. I've been directed towards the Python language because I was told it is good for beginners. I ultimately want to make games for OS X/iPhone. My problem is that I understand what I read but I can't apply my knowledge to anything. I am a programming noob. Should I stick with Python? (is there a better language I should be learning?) Where can I learn programming theory? I get very hyper when reading my book sometimes, any tips on staying calm and focusing? What are effective ways to learn how to program? Are there standard exercises for programming? (I feel solving problems helps my understanding immensely) Ultimately I feel like I am in a never ending tunnel that leads me no where. It feels like I am just completely unable to pursue anything in the world of programming, yet it is something I want to do very much. Thanks.

  Read the article

• Do you know a date picker to quickly pick one day of the current week?

  - by Murmelschlurmel

  Most date pickers allow you to pick the date from a tine calendar or enter the date by hand. For example http://jqueryui.com/demos/datepicker/ This requires - two clicks (one to display the calendar and one to select the correct date) - good eyesight (usually the pop-up calendar is very small) - and good hand-eye coordination to pick the correct date in the tiny calendar with your mouse. That's no problem for power users, but a hassle for older people and computer beginners. I found a website with a different approach. It seems like their users mostly select dates of the current week. So they listed all the days of the week in a bar together with the weekday. The current day is marked in another color. There is a tiny calender icon on the right hand that opens up a regular date picker. That gives you access to all regular date picker functionality. Here is a screenshot: http://mite.yo.lk/assets/img/tour/de/zeiten-erfassen.png Do you know of any jquery plugin which has a similar feature? If not, do you any other plugin or widget which would help me speed up development ? Thank you!

  Read the article

• what is meant by normalization in huge pointers

  - by wrapperm

  Hi, I have a lot of confusion on understanding the difference between a "far" pointer and "huge" pointer, searched for it all over in google for a solution, couldnot find one. Can any one explain me the difference between the two. Also, what is the exact normalization concept related to huge pointers. Please donot give me the following or any similar answers: "The only difference between a far pointer and a huge pointer is that a huge pointer is normalized by the compiler. A normalized pointer is one that has as much of the address as possible in the segment, meaning that the offset is never larger than 15. A huge pointer is normalized only when pointer arithmetic is performed on it. It is not normalized when an assignment is made. You can cause it to be normalized without changing the value by incrementing and then decrementing it. The offset must be less than 16 because the segment can represent any value greater than or equal to 16 (e.g. Absolute address 0x17 in a normalized form would be 0001:0001. While a far pointer could address the absolute address 0x17 with 0000:0017, this is not a valid huge (normalized) pointer because the offset is greater than 0000F.). Huge pointers can also be incremented and decremented using arithmetic operators, but since they are normalized they will not wrap like far pointers." Here the normalization concept is not very well explained, or may be I'm unable to understand it very well. Can anyone try explaining this concept from a beginners point of view. Thanks, Rahamath

  Read the article

• How to install Zend Framework on Windows

  - by sombe

  "installing Zend Framework is so easy!!!!" yeah right... Ok I'm working with a beginner's book and the ONE thing that is not excessively detailed is the most important part: Installing the darn thing. After browsing the quickstart guide for hours, all it said was: "download Zend [...] add the include directory (bla bla) and YOU'RE DONE!" right, i'm done using Zend. Ok, not really, not yet anyway. I beg of you people, I wanna go to bed, please tell me how (in simple 6th grade detail) to install the framework. I've got the unzipped folder in my htdocs directory, and I placed zf.bat+zf.php in the htdocs root. What's next? thank you so much. EDIT: Thanks guys for all the answers. Unfortunately I haven't been able to work with this or find a good enough resource to explain it to me in plain english. It seems that this framework adheres more so to programmers than to beginners. I've since yesterday read a little on CakePHP and found that it was incredibly easy to install and tune. As oppose to Zend Framework, where I had to dig in my "environment variables", configure "httpd.conf" and almost tie the knot between my computer driver cables to just get it running, CakePHP has already allowed me to put together a nice newbie application. In conclusion, I very much appreciate all of your help. I hope someone else venturing on ZF will be more successful with it. Thanks!

  Read the article

• Invalid controller using custom routes

  - by AlexW

  I've been following the instruction on how to create custom routes from the book Zend Framework - A Beginners Guide I've changed my application.ini file to include this routing information: resources.router.routes.static-content.route = /content/:page resources.router.routes.static-content.defaults.module = default resources.router.routes.static-content.defaults.controller = static-content resources.router.routes.static-content.defaults.view = static-content resources.router.routes.static-content.defaults.action = display Given the above configuration, I have this controller: <?php class Default_StaticContentController extends Zend_Controller_Action { public function init() { /* Initialize action controller here */ } public function displayAction() { // action body $page = $this->getRequest()->getParam('page'); if (file_exists($this->view->getScriptPath(null) . '/' . $this->getRequest()->getControllerName() . '/' . $page . $this->viewSuffix )) { $this->render($page); } else { throw new Zend_Controller_Action_Exception('HLC - Page not found', 404); } } } I have a view named about.phtml in the APPLICATION_PATH/modules/default/views/static-content folder. What ahppens is I get an error saying: An error occurred Page not found Exception information: Message: Invalid controller class ("StaticContentController") Stack trace: #0 /Applications/MAMP/htdocs/zend/library/Zend/Controller/Dispatcher/Standard.php(262): Zend_Controller_Dispatcher_Standard->loadClass('StaticContentCo...') #1 /Applications/MAMP/htdocs/zend/library/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #2 /Applications/MAMP/htdocs/zend/library/Zend/Application/Bootstrap/Bootstrap.php(97): Zend_Controller_Front->dispatch() #3 /Applications/MAMP/htdocs/zend/library/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run() #4 /Applications/MAMP/htdocs/HLC/public/index.php(26): Zend_Application->run() #5 {main} Request Parameters: array ( 'page' => 'about', 'module' => 'default', 'controller' => 'static-content', 'view' => 'static-content', 'action' => 'display', ) Note that it is not rendering my customised Zend_Controller_Action_Exception but throwing the global error. I'm using the URL: http://hlc.local:8888/content/about The default index action works ok, just this routing that's not working.

  Read the article

• Understanding how software testing works and what to test.

  - by RHaguiuda

  Intro: I've seen lots of topics here on SO about software testing and other terms I don't understand. Problem: As a beginner developer I, unfortunately, have no idea how software testing works, not even how to test a simple function. This is a shame, but thats the truth. I also hope this question can help others beginners developers too. Question: Can you help me to understand this subject a little bit more? Maybe some questions to start would help: When I develop a function, how should I test it? For example: when working with a sum function, should I test every input value possible or just some limits? How about testing functions with strings as parameters? In a big program, do I have to test every single piece of code of it? When you guys program do you test every code written? How automated test works and how can I try one? How tools for automated testing works and what they do? I`ve heard about unit testing. Can I have a brief explanation on this? What is a testing framework? If possible please post some code with examples to clarify the ideas. Any help on this topic is very welcome! Thanks.

  Read the article

• Begin game programming basics

  - by AJ

  My 14 year old kid brother wants to learn to program games. He has never programmed but would like to learn programming. His interest lies with games and game programming and he understands that it can be difficult but he wants to do that. So, obviously, I turned to SO folks to know what you feel on how he should go about it. Remember, please suggest on Areas that beginners can choose, how to begin in that area, what to read in the beginning, initial languages in the beginning etc. Once the beginning part is taken care of, you may also suggest the intermediate and advanced stuff but this question is about very beginning level. If there are areas like Web games Vs. console games Vs generic computer games, then please advice on the areas. As I said he has never programmed, he might want to try all the areas and choose the one he likes the best. I hope this is not too much to ask for someone who is in this field but if this question is huge, please advice on how to break it into multiple questions. ~Thanks.

  Read the article

• Sqlite3 prompting `...>` instead of `sqlite>`

  - by Imray

  I'm following a beginners tutorial to sqlite3. The first step is creating a new database. So I enter a name (movies.db). I'm expecting to get another sqlite> prompt on the next line, and continue with the tutorial, but instead I get a lame ...> after which I can type any gibbersish I want. Clearly, this is not good. What my command prompt looks like: SQLite version 3.8.1 2013-10-17 12:57:35 Enter ".help" for instructions Enter SQL statements terminated with a ";" sqlite> $ sqlite3 movies.db ...> gibberish ...> dsds ...> sdada ...> gfgys ...> a ...> Aaaaarrrgh! ...> How do I get sqlite3 to work normally for me? Pardon my newbie-ness. I hope I've phrased this question in a way that might help other newbs too.

  Read the article

• Noise with multi-threaded raytracer

  - by herber88

  This is my first multi-threaded implementation, so it's probably a beginners mistake. The threads handle the rendering of every second row of pixels (so all rendering is handled within each thread). The problem persists if the threads render the upper and lower parts of the screen respectively. Both threads read from the same variables, can this cause any problems? From what I've understood only writing can cause concurrency problems... Can calling the same functions cause any concurrency problems? And again, from what I've understood this shouldn't be a problem... The only time both threads write to the same variable is when saving the calculated pixel color. This is stored in an array, but they never write to the same indices in that array. Can this cause a problem? Multi-threaded rendered image (Spam prevention stops me from posting images directly..) Ps. I use the exactly same implementation in both cases, the ONLY difference is a single vs. two threads created for the rendering.

  Read the article

• is there a Java GUI for dummies ?

  - by MHero

  Hello, first I want to apologize about my english, it may be not clear enough. Well, I'm new to Java programming, and I search over this web about use of Swing, AWT, 2D, etc. but I didn't get the answer I was looking for. I want to know about a book or method to learn Java GUI programming (not even sure this is a propper term). Previous answers guide me to Filthy Rich Clients by Romain Guy and also to The Swing Tutorial in Sun Web Page. and No offense, but...the first one seems too complex and the second one a bit disorganize. so I ask about a more "for dummies" method. Thanks EDIT: Thanks everyboy, you're very kind and serious. I want to clear some things that I didn't state for being my first question. I dont' want to use autogenerated code(Don't want to say why only focus on my question for consistency) Also I've read Deitel & Deitel and it's a good beginners book but it seems to me that doesn't cover layout(and other details) Finally, I tried to read netbeans generated code but it's a mess find method by method and function by function the way that the IDE does it I hope this edition helps to solve my question

  Read the article

• basic file input using C

  - by user1781966

  So im working on learning how to do file I/O, but the book I'm using is terrible at teaching how to receive input from a file. Below is is their example of how to receive input from a file, but it doesn't work. I have copied it word for word, and it should loop through a list of names until it reaches the end of the file( or so they say in the book), but it doesn't. In fact if I leave the while loop in there, it doesn't print anything. #include <stdio.h> #include <conio.h> int main() { char name[10]; FILE*pRead; pRead=fopen("test.txt", "r"); if (pRead==NULL) { printf("file cannot be opened"); }else printf("contents of test.txt"); fscanf(pRead,"%s",name); while(!feof(pRead)) { printf("%s\n",name); fscanf(pRead, "%s", name); } getch(); } Even online, every beginners tutorial I see does some variation of this, but I can't seem to get it to work even a little bit.

  Read the article

• How i can fix the increasing order summation code?

  - by user2971559

  I want from the java to reads all numbers from the user as long as the number entered by user is bigger than the previous number. But i could write it for only positive numbers. How i can fix code below if all numbers included. If it is possible please write the solution for beginners because its my first year in computer science in college and I haven't learn a lot yet. import acm.program.*; public class IncreasingOrder extends ConsoleProgram { public void run() { int previousNumber = 0; int total = 0; int count = 0; while(true) { int n = readInt("Enter > "); if (n <= previousNumber) break; total += n; count++; previousNumber = n; } println("You have entered " + count + " numbers in increasing order."); println("Sum of these " + count + " numbers is " + total + "."); } }

  Read the article

• Things to Avoid in C/C++ [closed]

  - by piemesons

  Possible Duplicate: What C++ pitfalls should I avoid ? While searching for some information, I stumbled upon this series of small articles, Things to avoid in C/C++. So, thought of sharing it... "C/C++ programmers are allowed to do some things they shouldn't. We are given functions that are supposed to be useful but aren't because of hidden faults, or taught ways to do things that are bad, wrong, not necessary. These posts will discuss many of these as time goes on." gets(): http://www.gidnetwork.com/b-56.html fflush(stdin): http://www.gidnetwork.com/b-57.html feof(): http://www.gidnetwork.com/b-58.html system("PAUSE"): http://www.gidnetwork.com/b-61.html scanf: http://www.gidnetwork.com/b-59.html scanf / character: http://www.gidnetwork.com/b-60.html scanf / string: http://www.gidnetwork.com/b-62.html scanf / number: http://www.gidnetwork.com/b-63.html scanf / epilogue: http://www.gidnetwork.com/b-64.html void main(): http://www.gidnetwork.com/b-66.html As this is a very useful subject/topic, I request all the members to keep adding valuable information to this thread, and make it a good source of information for all level of programmers, especially for beginners. Thanks...

  Read the article

• Regex for ignoring consecutive quotation marks in string

  - by will-hart

  I have built a parser in Sprache and C# for files using a format I don't control. Using it I can correctly convert: a = "my string"; into my string The parser (for the quoted text only) currently looks like this: public static readonly Parser<string> QuotedText = from open in Parse.Char('"').Token() from content in Parse.CharExcept('"').Many().Text().Token() from close in Parse.Char('"').Token() select content; However the format I'm working with escapes quotation marks using "double doubles" quotes, e.g.: a = "a ""string""."; When attempting to parse this nothing is returned. It should return: a ""string"". Additionally a = ""; should be parsed into a string.Empty or similar. I've tried regexes unsuccessfully based on answers like this doing things like "(?:[^;])*", or: public static readonly Parser<string> QuotedText = from content in Parse.Regex("""(?:[^;])*""").Token() This doesn't work (i.e. no matches are returned in the above cases). I think my beginners regex skills are getting in the way. Does anybody have any hints? EDIT: I was testing it here - http://regex101.com/r/eJ9aH1

  Read the article

• How do I (robustly) remotely execute tasks on Windows workstations in a domain?

  - by Zac B

  I'm not even sure if "robustly" is a word. Anyway. Context: We have a few hundred Windows 7 workstations on a LAN. We use AD/GPO management pretty heavily, but there are a lot of periodic and/or manual maintenance tasks we need to do that can't be done via GPO/scheduled task. For example, say I want to execute program X (which runs silently, in the background, and doesn't bother the user) on workstation Y, or say I want to execute task A on a workstation group B either on a schedule or on demand. Kicking the users off of their computers to do this (i.e. using RDP) is a no-no, and doesn't work on groups anyway. Question: What's the best way to do this that is robust enough that, after setup, I could give it to beginner support people (read: people who are phobic of the command line, and get confused with GUI interfaces more complicated than Firefox)? I'm a competent programmer, and, if there is a robust set of tools or framework out there for this type of task, I'd consider hacking something together myself if it didn't take too long. If there's some combination of tools or techniques that others use to make remote-workstation-administration doable by beginners, I have yet to find it. For those who care about the "why": I'm midlevel IT, and was told to implement a remote management solution that allows arbitrary/scheduled remote execution, with confirmation that programs actually ran remotely, and the ability to view what they returned. "Why?" I asked, "Can't I just use PsExec and the task scheduler on a dispatcher machine?" "No," I was told, "'Joe' the second-week tech is going to be in charge of this one, and he needs something simple with a GUI." What I've tried: I've played with making a bunch of one-clickable "transfer files to remote computer and run them with PsExec" batch/VB scrips, but those tend to break down and don't easily support running on customizable groups. I've played a little bit with the Windows version of Puppet, but it doesn't support arbitrary-time remote execution (it's ability to group computers into a tree/node structure is really nice though). I've used an older version of Altiris, and, while it does a lot of what I want, it's interface is awful, it's slow, crashes a lot, and is probably too expensive for management. SwiftWater's DMS solution does some of what I want, but it's very underdeveloped, closed-source (not a deal breaker but not ideal), and I get the impression that support and reliability are lacking.

  Read the article

• RSS Feeds currently on Simple-Talk

  - by Andrew Clarke

  There are a number of news-feeds for the Simple-Talk site, but for some reason they are well hidden. Whilst we set about reorganizing them, I thought it would be a good idea to list some of the more important ones. The most important one for almost all purposes is the Homepage RSS feed which represents the blogs and articles that are placed on the homepage. Main Site Feed representing the Homepage ..which is good for most purposes but won't always have all the blogs, or maybe it will occasionally miss an article. If you aren't interested in all the content, you can just use the RSS feeds that are more relevant to your interests. (We'll be increasing these categories soon) The newsfeed for SQL articles The .NET section newsfeed The newsfeed for Red Gate books The newsfeed for Opinion articles The SysAdmin section newsfeed if you want to get a more refined feed, then you can pick and choose from these feeds for each category so as to make up your custom news-feed in the SQL section, SQL Training Learn SQL Server Database Administration TSQL Programming SQL Server Performance Backup and Recovery SQL Tools SSIS SSRS (Reporting Services) in .NET there are... ASP.NET Windows Forms .NET Framework ,NET Performance Visual Studio .NET tools in Sysadmin there are Exchange General Virtualisation Unified Messaging Powershell in opinion, there is... Geek of the Week Opinion Pieces in Books, there is .NET Books SQL Books SysAdmin Books And all the blogs have got feeds. So although you can get all the blogs from here.. Main Blog Feed          You can get individual RSS feeds.. AdamRG's Blog       Alex.Davies's Blog       AliceE's Blog       Andrew Clarke's Blog       Andrew Hunter's Blog       Bart Read's Blog       Ben Adderson's Blog       BobCram's Blog       bradmcgehee's Blog       Brian Donahue's Blog       Charles Brown's Blog       Chris Massey's Blog       CliveT's Blog       Damon's Blog       David Atkinson's Blog       David Connell's Blog       Dr Dionysus's Blog       drsql's Blog       FatherJack's Blog       Flibble's Blog       Gareth Marlow's Blog       Helen Joyce's Blog       James's Blog       Jason Crease's Blog       John Magnabosco's Blog       Laila's Blog       Lionel's Blog       Matt Lee's Blog       mikef's Blog       Neil Davidson's Blog       Nigel Morse's Blog       Phil Factor's Blog       red@work's Blog       reka.burmeister's Blog       Richard Mitchell's Blog       RobbieT's Blog       RobertChipperfield's Blog       Rodney's Blog       Roger Hart's Blog       Simon Cooper's Blog       Simon Galbraith's Blog       TheFutureOfMonitoring's Blog       Tim Ford's Blog       Tom Crossman's Blog       Tony Davis's Blog       As well as these blogs, you also have the forums.... SQL Server for Beginners Forum     Programming SQL Server Forum    Administering SQL Server Forum    .NET framework Forum    .Windows Forms Forum   ASP.NET Forum   ADO.NET Forum 

  Read the article

• SQL SERVER – Beginning of SQL Server Architecture – Terminology – Guest Post

  - by pinaldave

  SQL Server Architecture is a very deep subject. Covering it in a single post is an almost impossible task. However, this subject is very popular topic among beginners and advanced users.  I have requested my friend Anil Kumar who is expert in SQL Domain to help me write  a simple post about Beginning SQL Server Architecture. As stated earlier this subject is very deep subject and in this first article series he has covered basic terminologies. In future article he will explore the subject further down. Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. In this Article we will discuss about MS SQL Server architecture. The major components of SQL Server are: Relational Engine Storage Engine SQL OS Now we will discuss and understand each one of them. 1) Relational Engine: Also called as the query processor, Relational Engine includes the components of SQL Server that determine what your query exactly needs to do and the best way to do it. It manages the execution of queries as it requests data from the storage engine and processes the results returned. Different Tasks of Relational Engine: Query Processing Memory Management Thread and Task Management Buffer Management Distributed Query Processing 2) Storage Engine: Storage Engine is responsible for storage and retrieval of the data on to the storage system (Disk, SAN etc.). to understand more, let’s focus on the following diagram. When we talk about any database in SQL server, there are 2 types of files that are created at the disk level – Data file and Log file. Data file physically stores the data in data pages. Log files that are also known as write ahead logs, are used for storing transactions performed on the database. Let’s understand data file and log file in more details: Data File: Data File stores data in the form of Data Page (8KB) and these data pages are logically organized in extents. Extents: Extents are logical units in the database. They are a combination of 8 data pages i.e. 64 KB forms an extent. Extents can be of two types, Mixed and Uniform. Mixed extents hold different types of pages like index, System, Object data etc. On the other hand, Uniform extents are dedicated to only one type. Pages: As we should know what type of data pages can be stored in SQL Server, below mentioned are some of them: Data Page: It holds the data entered by the user but not the data which is of type text, ntext, nvarchar(max), varchar(max), varbinary(max), image and xml data. Index: It stores the index entries. Text/Image: It stores LOB ( Large Object data) like text, ntext, varchar(max), nvarchar(max),  varbinary(max), image and xml data. GAM & SGAM (Global Allocation Map & Shared Global Allocation Map): They are used for saving information related to the allocation of extents. PFS (Page Free Space): Information related to page allocation and unused space available on pages. IAM (Index Allocation Map): Information pertaining to extents that are used by a table or index per allocation unit. BCM (Bulk Changed Map): Keeps information about the extents changed in a Bulk Operation. DCM (Differential Change Map): This is the information of extents that have modified since the last BACKUP DATABASE statement as per allocation unit. Log File: It also known as write ahead log. It stores modification to the database (DML and DDL). Sufficient information is logged to be able to: Roll back transactions if requested Recover the database in case of failure Write Ahead Logging is used to create log entries Transaction logs are written in chronological order in a circular way Truncation policy for logs is based on the recovery model SQL OS: This lies between the host machine (Windows OS) and SQL Server. All the activities performed on database engine are taken care of by SQL OS. It is a highly configurable operating system with powerful API (application programming interface), enabling automatic locality and advanced parallelism. SQL OS provides various operating system services, such as memory management deals with buffer pool, log buffer and deadlock detection using the blocking and locking structure. Other services include exception handling, hosting for external components like Common Language Runtime, CLR etc. I guess this brief article gives you an idea about the various terminologies used related to SQL Server Architecture. In future articles we will explore them further. Guest Author  The author of the article is Anil Kumar Yadav is Trainer, SQL Domain, Koenig Solutions. Koenig is a premier IT training firm that provides several IT certifications, such as Oracle 11g, Server+, RHCA, SQL Server Training, Prince2 Foundation etc. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Security, SQL Server, SQL Tips and Tricks, SQL Training, T SQL, Technology

  Read the article

• SQL SERVER – SQL in Sixty Seconds – 5 Videos from Joes 2 Pros Series – SQL Exam Prep Series 70-433

  - by pinaldave

  Joes 2 Pros SQL Server Learning series is indeed fun. Joes 2 Pros series is written for beginners and who wants to build expertise for SQL Server programming and development from fundamental. In the beginning of the series author Rick Morelan is not shy to explain the simplest concept of how to open SQL Server Management Studio. Honestly the book starts with that much basic but as it progresses further Rick discussing about various advanced concepts from query tuning to Core Architecture. This five part series is written with keeping SQL Server Exam 70-433. Instead of just focusing on what will be there in exam, this series is focusing on learning the important concepts thoroughly. This book no way take short cut to explain any concepts and at times, will go beyond the topic at length. The best part is that all the books has many companion videos explaining the concepts and videos. Every Wednesday I like to post a video which explains something in quick few seconds. Today we will go over five videos which I posted in my earlier posts related to Joes 2 Pros series. Introduction to XML Data Type Methods – SQL in Sixty Seconds #015 The XML data type was first introduced with SQL Server 2005. This data type continues with SQL Server 2008 where expanded XML features are available, most notably is the power of the XQuery language to analyze and query the values contained in your XML instance. There are five XML data type methods available in SQL Server 2008: query() – Used to extract XML fragments from an XML data type. value() – Used to extract a single value from an XML document. exist() – Used to determine if a specified node exists. Returns 1 if yes and 0 if no. modify() – Updates XML data in an XML data type. node() – Shreds XML data into multiple rows (not covered in this blog post). [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Error Actions – SQL in Sixty Seconds #014 Most people believe that when SQL Server encounters an error severity level 11 or higher the remaining SQL statements will not get executed. In addition, people also believe that if any error severity level of 11 or higher is hit inside an explicit transaction, then the whole statement will fail as a unit. While both of these beliefs are true 99% of the time, they are not true in all cases. It is these outlying cases that frequently cause unexpected results in your SQL code. To understand how to achieve consistent results you need to know the four ways SQL Error Actions can react to error severity levels 11-16: Statement Termination – The statement with the procedure fails but the code keeps on running to the next statement. Transactions are not affected. Scope Abortion – The current procedure, function or batch is aborted and the next calling scope keeps running. That is, if Stored Procedure A calls B and C, and B fails, then nothing in B runs but A continues to call C. @@Error is set but the procedure does not have a return value. Batch Termination – The entire client call is terminated. XACT_ABORT – (ON = The entire client call is terminated.) or (OFF = SQL Server will choose how to handle all errors.) [Detailed Blog Post] | [Quiz with Answer] Introduction to Basics of a Query Hint – SQL in Sixty Seconds #013 Query hints specify that the indicated hints should be used throughout the query. Query hints affect all operators in the statement and are implemented using the OPTION clause. Cautionary Note: Because the SQL Server Query Optimizer typically selects the best execution plan for a query, it is highly recommended that hints be used as a last resort for experienced developers and database administrators to achieve the desired results. [Detailed Blog Post] | [Quiz with Answer] Introduction to Hierarchical Query – SQL in Sixty Seconds #012 A CTE can be thought of as a temporary result set and are similar to a derived table in that it is not stored as an object and lasts only for the duration of the query. A CTE is generally considered to be more readable than a derived table and does not require the extra effort of declaring a Temp Table while providing the same benefits to the user. However; a CTE is more powerful than a derived table as it can also be self-referencing, or even referenced multiple times in the same query. A recursive CTE requires four elements in order to work properly: Anchor query (runs once and the results ‘seed’ the Recursive query) Recursive query (runs multiple times and is the criteria for the remaining results) UNION ALL statement to bind the Anchor and Recursive queries together. INNER JOIN statement to bind the Recursive query to the results of the CTE. [Detailed Blog Post] | [Quiz with Answer] Introduction to SQL Server Security – SQL in Sixty Seconds #011 Let’s get some basic definitions down first. Take the workplace example where “Tom” needs “Read” access to the “Financial Folder”. What are the Securable, Principal, and Permissions from that last sentence? A Securable is a resource that someone might want to access (like the Financial Folder). A Principal is anything that might want to gain access to the securable (like Tom). A Permission is the level of access a principal has to a securable (like Read). [Detailed Blog Post] | [Quiz with Answer] Please leave a comment explain which one was your favorite video as that will help me understand what works and what needs improvement. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology, Video

  Read the article

• University teaches DOS-style C++, how to deal with it

  - by gaidal

  Half a year ago I had a look at available programming educations. I chose this one because unlike most of the choices: The majority of the courses seemed to be about something concrete and useful; the languages used are C++ and Java which are platform-independent; later courses include developing for mobile devices and a course on Android development, which seemed modern and relevant. Now after two introductory courses we're just starting with C++, and my programming professor seems a bit weird. He's tested us on things like "why should you use constants" and "why are globals bad" in a kind of mechanical way, without much context, before teaching actual programming. His handouts use system("pause"), system("cls"), and getch() from some conio.h that seems ancient according to what I've read. I just did a task that was about printing the "ASCII letters from 32 to 255" (huh?), with an example picture showing a table with Windows' Extended ASCII - of course I got other results for 128-255 on my Arch Linux that uses Unicode, and this isn't mentioned at all. I don't know, it just doesn't seem right... As if he is teaching programming because he has to, perhaps? Should I bring such things up? Hmm. I was looking forward to learning from someone who really knows stuff, and in an academic, rigorous way, like SICP or something. Aren't professors in programming supposed to be like that? I studied math for a while and every teacher and assistant there were really precise about what they said, but this is my second programming teacher that is sort of disappointing. Oh well. Now, question: Is this what to expect from universities or Not OK, and how do I deal with it? I have never touched the language C++ (or C) until now, and am not the right person to jump up and say "This is So Wrong!", so if I google something and find 10 people who say "xxx is blasphemy", how do I skillfully communicate this? I do think it would be better for those classmates who are total beginners not to learn bad habits (such as these vibes of total ignorance of other platforms!) during the upcoming courses, but don't want to disrespect the teacher. I don't know if it's reasonable or just cocky to bring up things like "what about other platforms?" or "but what about this article or stackoverflow answer that I read that said..." for every assignment? Or, if he keeps ignoring non-Windows-programming, should I give up and focus on my own projects or somehow argue that this really isn't OK nowadays? Are there any programming teachers out there, what do you think? By the way these are web-based courses, all interaction between teachers and students takes place in a forum. EDIT: A few answers seem to be making some incorrect assumptions, so maybe I should add a few things. I have been doing programming for fun on and off for 10 years, am pretty comfortable in 3 languages and read programming blogs et c regularly. Also, I feel kind of done being a student, having a degree in another field. I just need another, relevant diploma to work as a programmer, so I'm going back for that. Studying computer science for 5 years is not for me anymore, even though I enjoy learning and solving problems in my free time. Second, let me highlight that I don't expect it to be like the industry at all, quite the contrary. I expect it to be academic, dry and unnecessarily correct. No, it's not just math. Every professor I have had in math, or Japanese (major) or Chinese (minor) have been very very academic, discussing subtle points for hours with passion. But the courses I'm taking now and a previous one in programming don't seem serious. They neither resemble industry NOR academia. That is the problem. And it's not because I can't learn programming anyway. Third, I don't necessarily want to learn C++ or Android development, and I know I could teach myself those and anything else if I wanted to. But I am going back to school anyway, and those platform-independent languages and mobile stuff made me think that maybe they're serious about teaching something relevant here. Seems like I got this wrong, but we'll see.

  Read the article

• View overlapping with RelativeLayout on Android 1.5

  - by Justin

  I am having a problem with views overlapping in a RelativeLayout on Android 1.5... Everything is working fine on Android 1.6 and above. I do understand that Android 1.5 has some issues with RelativeLayout, but I was not able to find anything on StackOverflow or the android beginners group for my specific problem. My layout consists of four sections, each of which are made up of a TextView, a Gallery, and another TextView aligned vertically: Running Apps Recent Apps Services Processes When all four sets of these items are displayed everything works fine. However, my app allows the user to specify that some of these are not displayed. If the user turns off Running Apps, Recent Apps, or Services then the remaining sections all of a sudden overlap eachother. Here is my code for the layout. I'm not sure what I am doing wrong. When the user turns off display of a section I use the View.GONE visibility setting: <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center_vertical" android:layout_gravity="center_vertical" android:background="@null" > <!-- Running Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/running_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/running_title" /> <Gallery android:id="@+id/running_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/running_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_id" android:gravity="center_horizontal" /> <!-- Recent Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/recent_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/running_gallery_current_text_id" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/recent_title" /> <Gallery android:id="@+id/recent_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/recent_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_id" android:gravity="center_horizontal" /> <!-- Service Gallery View Items --> <TextView style="@style/TitleText" android:id="@+id/service_gallery_title_text_id" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_below="@id/recent_gallery_current_text_id" android:gravity="left" android:paddingLeft="1sp" android:paddingRight="10sp" android:text="@string/service_title" /> <Gallery android:id="@+id/service_gallery_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/service_gallery_title_text_id" android:spacing="5sp" android:clipChildren="false" android:clipToPadding="false" android:unselectedAlpha=".5" /> <TextView style="@style/SubTitleText" android:id="@+id/service_gallery_current_text_id" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_below="@id/service_gallery_id" android:gravity="center_horizontal" /> </RelativeLayout> I ommitted the xml for the Processes section in a (somewhat vain) attempt to keep this shorter... What can I do to make this work in Android 1.5? I don't think it is just a matter of reordering the views in the xml because it works fine when everything is displayed.

  Read the article

< Previous Page | 12 13 14 15 16 17 18  | Next Page >