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  • Monitoring .NET ASP.NET Applications

    - by James Hollingworth
    I have a number of applications running on top of ASP.NET I want to monitor. The main things I care about are: Exceptions: We currently some custom code which will email us when an exception occurs. If the application is failing hard it will crash our outlook... I know (and use) elmah which partly solves the problem however it is still just a big table of exceptions with a pretty(ish) UI. I want something that makes sense of all of these exceptions (e.g. groups exceptions, alerts when new ones occur, tells me what the common ones are that I should fix, etc) Logging: We currently log to files which are then accessible via a shared folder which dev's grep & tail. Does anyone know of better ways of presenting this information. In an ideal world I want to associate it with exceptions. Performance: Request times, memory usage, cpu, etc. whatever stats I can get I'm guessing this is probably going to be solved by a number of tools, has anyone got any suggestions?

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  • .NET Regex: Howto extract IPv6 address parts

    - by Quandary
    Question: How does the .NET regex string to extract IPv6 addresses look like ? I can get it to extract a simple IPv6 address like "1050:0:0:0:5:600:300c:326b" but not the colon format ("ff06::c3"); My problem is, it should extract a 0 for every omitted value between the :: How do I do that? Below my code + description. Specify IPv6 addresses by omitting leading zeros. For example, IPv6 address 1050:0000:0000:0000:0005:0600:300c:326b may be written as 1050:0:0:0:5:600:300c:326b. Double colon Specify IPv6 addresses by using double colons (::) in place of a series of zeros. For example, IPv6 address ff06:0:0:0:0:0:0:c3 may be written as ff06::c3. Double colons may be used only once in an IP address. strInputString = "ff06::c3"; strInputString = "1050:0000:0000:0000:0005:0600:300c:326b"; string strPattern = "([A-Fa-f0-9]{1,4}:){7}([A-Fa-f0-9]{1,4})"; //strPattern = @"\A(?:[0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}\z"; //strPattern = @"(\A([0-9a-f]{1,4}:){1,1}(:[0-9a-f]{1,4}){1,6}\Z)|(\A([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,5}\Z)|(\A([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4}){1,4}\Z)|(\A([0-9a-f]{1,4}:){1,4}(:[0-9a-f]{1,4}){1,3}\Z)|(\A([0-9a-f]{1,4}:){1,5}(:[0-9a-f]{1,4}){1,2}\Z)|(\A([0-9a-f]{1,4}:){1,6}(:[0-9a-f]{1,4}){1,1}\Z)|(\A(([0-9a-f]{1,4}:){1,7}|:):\Z)|(\A:(:[0-9a-f]{1,4}){1,7}\Z)|(\A((([0-9a-f]{1,4}:){6})(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3})\Z)|(\A(([0-9a-f]{1,4}:){5}[0-9a-f]{1,4}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3})\Z)|(\A([0-9a-f]{1,4}:){5}:[0-9a-f]{1,4}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,1}(:[0-9a-f]{1,4}){1,4}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,3}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4}){1,2}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A([0-9a-f]{1,4}:){1,4}(:[0-9a-f]{1,4}){1,1}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A(([0-9a-f]{1,4}:){1,5}|:):(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z)|(\A:(:[0-9a-f]{1,4}){1,5}:(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\Z) "; //strPattern = @"/^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$/"; //strPattern = @"(:?[0-9a-fA-F]{1,4}:){7}([0-9a-fA-F]{1,4})\z"; //strPattern = @"\A((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)::((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)\z"; //strPattern = @"\A((?:[0-9A-Fa-f]{1,4}(?::[0-9A-Fa-f]{1,4})*)?)::((?:[0-9A-Fa-f]{1,4}:)*)(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\z"; //strPattern = @"/^(?:(?:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9](?::|$)){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|(?:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|(?:(?!(?:.*[a-f0-9]:){5,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?))?(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))(?:\.(?:(?:25[0-5])|(?:2[0-4][0-9])|(?:1[0-9]{2})|(?:[1-9]?[0-9]))){3}))$/i"; System.Text.RegularExpressions.Regex reValidationRule = new System.Text.RegularExpressions.Regex("^" + strPattern + "$"); if (reValidationRule.Match(strInputString).Success) // If matching pattern { System.Text.RegularExpressions.Match maResult = System.Text.RegularExpressions.Regex.Match(strInputString, strPattern); // Console.WriteLine(maResult.Groups.Count) string[] astrReturnValues = new string[4]; System.Text.RegularExpressions.GroupCollection gc = maResult.Groups; System.Text.RegularExpressions.CaptureCollection cc; int counter; //System.Web.Script.Serialization.JavaScriptSerializer jssJSONserializer = new System.Web.Script.Serialization.JavaScriptSerializer(); //Console.WriteLine(jssJSONserializer.Serialize()); // Loop through each group. for (int i = 0; i < gc.Count; i++) { Console.WriteLine("Group: {0}", i); cc = gc[i].Captures; counter = cc.Count; // Print number of captures in this group. Console.WriteLine("Captures count = " + counter.ToString()); // Loop through each capture in group. for (int ii = 0; ii < counter; ii++) { Console.WriteLine("Capture: {0}", ii); // Print capture and position. Console.WriteLine(cc[ii] + " Starts at character " + cc[ii].Index); } }

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  • Where is SQLite on Nokia N810? How to get?

    - by klausnrooster
    I need SQLite3 with the TCL interface for a simple command-line app I use on all my PCs and want to use on my new (to me) Nokia N810. But "find" does not find any SQLite on the Nokia N810. Several apps use it, supposedly, like the maps/gps (poi.db), and others. I got sudo gainroot before using find, tried with wildcards * and dot . No luck. I guess it's embedded in the apps that use it? The N810's app manager doesn't offer SQLite. Apt-get has it and then fails with error: "Unable to fetch some archives, ..." The "update" and "--fix-missing" options do not help. I don't really want to get scratchbox and compile SQLite and TCL extension for it from sources. I looked at README and it seems like it might be straightforward. However [1] it's not clear what scratchbox download I would need (there are dozens in the Index of /download/files/sbox-releases/hathor/deb/i386), [2] I've never compiled any C sources successfully before, [3] and the whole mess entails a lot of learning curve for what is a very small one-off personal project. http://www.gronmayer.com/ has a few (sqlite (v. 2.8.17-4), libsqlite0 (v. 2.8.17-4), and libsqlite0-dev (v. 2.8.17-4)) but they appear to part of some huge package, may or may not include the TCL interface, ... and no I don't want to port my tiny app to Python. Is there some option I've overlooked? Must I get scratchbox and compile for ARM myself? Thanks for your time.

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  • F# in ASP.NET, mathematics and testing

    - by DigiMortal
    Starting from Visual Studio 2010 F# is full member of .NET Framework languages family. It is functional language with syntax specific to functional languages but I think it is time for us also notice and study functional languages. In this posting I will show you some examples about cool things other people have done using F#. F# and ASP.NET As I am ASP/ASP.NET MVP I am – of course – interested in how people use different languages and technologies with ASP.NET. C# MVP Tomáš Petrícek writes about developing ASP.NET MVC applications using F#. He also shows how to use LINQ To SQL in F# (using F# PowerPack) and provides sample solution and Visual Studio 2010 template for F# MVC web applications. You may also find interesting how you can create controllers in F#. Excellent work, Tomáš! Vladimir Matveev has interesting example about how to use F# and ApplicationHost class to process ASP.NET requests ouside of IIS. This is simple and very straight-forward example and I strongly suggest you to take a look at it. Very cool example is project Strom in Codeplex. Storm is web services testing tool that is fully written on F#. Take a look at this site because Codeplex offers also source code besides binaries. Math Functional languages are strong in fields like mathematics and physics. When I wrote my C# example about BigInteger class I found out that recursive version of Fibonacci algorithm in C# is not performing well. In same time I made same experiment on F# and in F# there were no performance problems with recursive version. You can find F# version of Fibonacci algorithm from Bob Palmer’s blog posting Fibonacci numbers in F#. Although golden spiral is useful for solving many problems I looked for some practical code example and found one. Kean Walmsley published in his Through the Interface blog very interesting posting Creating Fibonacci spirals in AutoCAD using F#. There are also other cool examples you may be interested in. Using numerical components by Extreme Optimization  it is possible to make some numerical integration (quadrature method) using F# (also C# example is available). fsharp.it introduces factorials calculation on F#. Robert Pickering has made very good work on programming The Game of Life in Silverlight and F# – I definitely suggest you to try out this example as it is very illustrative too. Who wants something more complex may take a look at Newton basin fractal example in F# by Jonathan Birge. Testing After some searching and surfing I found out that there is almost everything available for F# to write tests and test your F# code. FsCheck - FsCheck is a port of Haskell's QuickCheck. Important parts of the manual for using FsCheck is almost literally "adapted" from the QuickCheck manual and paper. Any errors and omissions are entirely my responsibility. FsTest - This project is designed to Language Oriented Programming constructs around unit testing and behavior testing in F#. The goal of this project is to create a Domain Specific Language for testing F# code in a way that makes sense for functional programming. FsUnit - FsUnit makes unit-testing with F# more enjoyable. It adds a special syntax to your favorite .NET testing framework. xUnit.NET - xUnit.net is a developer testing framework, built to support Test Driven Development, with a design goal of extreme simplicity and alignment with framework features. It is compatible with .NET Framework 2.0 and later, and offers several runners: console, GUI, MSBuild, and Visual Studio integration via TestDriven.net, CodeRush Test Runner and Resharper. It also offers test project integration for ASP.NET MVC. Getting started Well, as a first thing you need Visual Studio 2010. Then take a look at these resources: F# samples @ MSDN Microsoft F# Developer Center @ MSDN F# Language Reference @ MSDN F# blog F# forums Real World Functional Programming: With Examples in F# and C# (Amazon) Happy F#-ing! :)

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  • Is ASP.NET MVC completely (and exclusively) based on conventions?

    - by Mike Valeriano
    --TL;DR Is there a "Hello World!" ASP.NET MVC tutorial out there that doesn't rely on conventions and "stock" projects? Is it even possible to take advantage of the technology without reusing the default file structure, and start from a single "hello_world.asp" file or something (like in PHP)? Am I completely mistaken and I should be looking somewhere else, maybe this? I'm interested in the MVC framework, not Web Forms --Background I've played a bit with PHP in the past, just for fun, and now I'm back to it since web development became relevant for me once again. I'm no professional, but I try to gain as much knowledge and control over the technology I'm working with as possible. I'm using Visual Studio 2012 for C# - my "desktop" language of choice - and since I got the Professional Edition from Dreamspark, the Web Development Tools are available, including ASP.NET MVC 4. I won't touch Web Forms, but the MVC Framework got my attention because the MVC pattern is something I can really relate to, since it provides the control I want but... not quite. Learning PHP was easy - and right form the start I could just create a "hello_world.php" file and just do something like this for immediate results: <!-- file: hello_world.php --> <?php> echo "Hello World!"; <?> But I couldn't find a single ASP.NET (MVC) tutorial out there (I'll be sure to buy one of the upcoming MVC 4 books, only a month away or so) that would start like that. They all start with a sample project, building up knowledge from the basics and heavily using conventions as they go along. Which is fine, I suppose, but it's now the best way for me to learn things. Even the "Empty" project template for a new ASP.NET MVC 4 Application in VS2012 is not empty at all: several files and folders are created for you - much like a new C# desktop application project, but with C# I can in fact start from scratch, creating the project structure myself. It is not the case with PHP: I can choose from a plethora of different MVC frameworks I can just create my own framework I can just skip frameworks altogether, and toss random PHP along with my HTML on a single file and make it work I understand the framework needs to establish some rules, but what if I just want to create a single page website with some C# logic behind it? Do I really need to create a whole bloat of files and folders for the sake of convention? Also, please understand that I haven't gotten far on any of those tutorials mainly because of this reason, but, if that's the only way to do it, I'll go for it using one of the books I've mentioned before. This is my first contact with ASP.NET but from the few comparisons I've read, I believe I should stay the hell away from Web Forms. Thank you. (Please forgive the broken English - it is not my primary language.)

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  • Guest (and occasional co-host) on Jesse Liberty's Yet Another Podcast

    - by Jon Galloway
    I was a recent guest on Jesse Liberty's Yet Another Podcast talking about the latest Visual Studio, ASP.NET and Azure releases. Download / Listen: Yet Another Podcast #75–Jon Galloway on ASP.NET/ MVC/ Azure Co-hosted shows: Jesse's been inviting me to co-host shows and I told him I'd show up when I was available. It's a nice change to be a drive-by co-host on a show (compared with the work that goes into organizing / editing / typing show notes for Herding Code shows). My main focus is on Herding Code, but it's nice to pop in and talk to Jesse's excellent guests when it works out. Some shows I've co-hosted over the past year: Yet Another Podcast #76–Glenn Block on Node.js & Technology in China Yet Another Podcast  #73 - Adam Kinney on developing for Windows 8 with HTML5 Yet Another Podcast #64 - John Papa & Javascript Yet Another Podcast #60 - Steve Sanderson and John Papa on Knockout.js Yet Another Podcast #54–Damian Edwards on ASP.NET Yet Another Podcast #53–Scott Hanselman on Blogging Yet Another Podcast #52–Peter Torr on Windows Phone Multitasking Yet Another Podcast #51–Shawn Wildermuth: //build, Xaml Programming & Beyond And some more on the way that haven't been released yet. Some of these I'm pretty quiet, on others I get wacky and hassle the guests because, hey, not my podcast so not my problem. Show notes from the ASP.NET / MVC / Azure show: What was just released Visual Studio 2012 Web Developer features ASP.NET 4.5 Web Forms Strongly Typed data controls Data access via command methods Similar Binding syntax to ASP.NET MVC Some context: Damian Edwards and WebFormsMVP Two questions from Jesse: Q: Are you making this harder or more complicated for Web Forms developers? Short answer: Nothing's removed, it's just a new option History of SqlDataSource, ObjectDataSource Q: If I'm using some MVC patterns, why not just move to MVC? Short answer: This works really well in hybrid applications, doesn't require a rewrite Allows sharing models, validation, other code between Web Forms and MVC ASP.NET MVC Adaptive Rendering (oh, also, this is in Web Forms 4.5 as well) Display Modes Mobile project template using jQuery Mobile OAuth login to allow Twitter, Google, Facebook, etc. login Jon (and friends') MVC 4 book on the way: Professional ASP.NET MVC 4 Windows 8 development Jesse and Jon announce they're working on a new book: Pro Windows 8 Development with XAML and C# Jon and Jesse agree that it's nice to be able to write Windows 8 applications using the same skills they picked up for Silverlight, WPF, and Windows Phone development. Compare / contrast ASP.NET MVC and Windows 8 development Q: Does ASP.NET and HTML5 development overlap? Jon thinks they overlap in the MVC world because you're writing HTML views without controls Jon describes how his web development career moved from a preoccupation with server code to a focus on user interaction, which occurs in the browser Jon mentions his NDC Oslo presentation on Learning To Love HTML as Beautiful Code Q: How do you apply C# / XAML or HTML5 skills to Windows 8 development? Q: If I'm a XAML programmer, what's the learning curve on getting up to speed on ASP.NET MVC? Jon describes the difference in application lifecycle and state management Jon says it's nice that web development is really interactive compared to application development Q: Can you learn MVC by reading a book? Or is it a lot bigger than that? What is Azure, and why would I use it? Jon describes the traditional Azure platform mode and how Azure Web Sites fits in Q: Why wouldn't Jesse host his blog on Azure Web Sites? Domain names on Azure Web Sites File hosting options Q: Is Azure just another host? How is it different from any of the other shared hosting options? A: Azure gives you the ability to scale up or down whenever you want A: Other services are available if or when you want them

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  • Asp.Net membership via ASP.NET Website Administrator Tool

    - by luppi
    I created a database with aspnet_regsql, the database was created in sql sever 2008 and not in data folder in my project (do I need to move it to the folder manually?). Next, in Web Site Administration Tool I went to provider section and clicked don Test button. I got an error: Could not establish a connection to the database. If you have not yet created the SQL Server database, exit the Web Site Administration tool, use the aspnet_regsql command-line utility to create and configure the database, and then return to this tool to set the provider. Maybe I need to set something in a web.config, like membership settings or connection strings (or ASP.NET Website Administrator Tool should create those settings for me)? Update: Maybe it happens because I am using SQL server 2008 full and not express? Update 2: After setting membership section and connection string to my aspnetdb database in Web Site Administration Tool I've opened security-Security Setup Wizard-Define Roles (stage 4) I got this error: An error was encountered. Please return to the previous page and try again. The following message may help in diagnosing the problem: Unable to connect to SQL Server database. at System.Web.Administration.WebAdminPage.CallWebAdminHelperMethod(Boolean isMembership, String methodName, Object[] parameters, Type[] paramTypes) at ASP.security_wizard_wizardpermission_ascx.OnInit(EventArgs e) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Control.InitRecursive(Control namingContainer) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

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  • creating Linq to sqlite dbml from DbLinq source code

    - by Veer
    Hi All, I tried to create linq-to-sqlite dbml using DbLinq but in vain. Each time I get different type of errors. May be I'm somewhere wrong. Can anyone tell me the step by step procedure to create the dbml file from the Dblinq source code. Edit: Steps I Followed: I downloaded the source file from this link. Edited the "run_sqliteMetal.bat" file in \\DbLinq-0.19\src\DbMetal folder as 'DbMetal.exe -database:myDb.db3 -namespace:myNS -code:myCode.cs' -dbml:myDbml.dbml Tried to run the DbMetal project file to produce the executable but there was a runtime error since Options object in Parameters.cs was null. Hence downloaded the readymade exe file from this location Copied it into the \DbLinq-0.19\src\DbMetal folder Executed the "run_sqliteMetal.bat" file I got a blank screen and Windows Error Msg "DbLinq has stopped Working" Any help? Thanks in advance, Veer

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  • ADD COLUMN to sqlite db IF NOT EXISTS - flex/air sqlite?

    - by Adam
    I've got a flex/air app I've been working on, it uses a local sqlite database that is created on the initial application start. I've added some features to the application and in the process I had to add a new field to one of the database tables. My questions is how to I go about getting the application to create one new field that is located in a table that already exists? this is a the line that creates the table stmt.text = "CREATE TABLE IF NOT EXISTS tbl_status ("+"status_id INTEGER PRIMARY KEY AUTOINCREMENT,"+" status_status TEXT)"; And now I'd like to add a status_default field. thanks! Thanks - MPelletier I've add the code you provided and it does add the field, but now the next time I restart my app I get an error - 'status_default' already exists'. So how can I go about adding some sort of a IF NOT EXISTS statement to the line you provided?

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  • Studying MySQL, SQLite source code to learn about RDBMS implementation

    - by Yang
    I know implementing database is a huge topic, but I want to have a basic understanding of how database systems work (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database. Since there are a few already proven very robust open source databases like mysql, sqlite and so on. However, the code are very complicated and I have no clue where to start. Also I find that the old school database textbooks are only explaining the theory, not the implementation details. Can anyone suggest how I should get started and if there are any books that emphasis on the technology and techniques of building dbms used in modern database industry?

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  • Pylons, SQlite and autoincrementing fields

    - by Maxfrank
    Hey! Just started working with Pylons in conjunction with SQLAlchemy, and my model looks something like this: from sqlalchemy import Column from sqlalchemy.types import Integer, String from helloworld.model.meta import Base class Person(Base): __tablename__ = "person" id = Column(Integer, primary_key=True) name = Column(String(100)) email = Column(String(100)) def __init__(self, name='', email=''): self.name = name self.email = email def __repr__(self): return "<Person('%s')" % self.name To avoid sqlite reusing id's that might have been deleted, I want to add AUTOINCREMENT to the column "id". I've looked through the documentation for sqlalchemy and saw that the sqlite_autoincrement can be issued. An example where this attribute is given can be found here. sqlite_autoincrement seems though to be issued when creating the table itself, and I just wondered how it can be supplied when using a declarative style of the model such as mine.

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  • SQLITE problem in rowid

    - by Saurabh
    I am using SQLite C# library and as per my requirement, before going to add I am retreving the rowid of that table. It is working fine but hetting error when table is empty. Once we add any data(a row) then it’s working fine . mDbCon = GetConnection(); SQLiteCommand cmd = mDbCon.CreateCommand(); cmd.CommandText = " SELECT MAX(rowid) FROM " + “MYTABLE”; cmd.CommandType = CommandType.Text; mDbCon.Open(); SQLiteDataReader sqReader = cmd.ExecuteReader(); while (sqReader.Read()) { if ( sqReader.IsDBNull(0) ) { max = (Int32)sqReader.GetInt32(0); } } mDbCon.Close(); It’s throwing exception when table “MYTABLE” don’t have any data.

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  • sqlite on iphone can open db but not prepare statements

    - by jan
    I'm brand new to using sqlite so I may have missed something basic. I've created a database and copied it into my app's document's directory. I'm able to open it but when I make a call to sqlite3_prepare_v2 I receive SQLITE_ERROR, "SQL error or missing database". here's my code: sqlite3 *database; if(sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) { sqlite3_stmt *compiledStatement; NSString *sqlStatement = @"select * from dbname"; int result = sqlite3_prepare_v2(database, [sqlStatement UTF8String], -1, &compiledStatement, nil); ... } the same sql statement works in the terminal. I've found this question in a few places either without answers or with solutions that don't fix my problem. I'm hoping someone here will be able to help. Thanks.

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  • Declaring data types in SQLite

    - by dan04
    I'm familiar with how type affinity works in SQLite: You can declare column types as anything you want, and all that matters is whether the type name contains "INT", "CHAR", "FLOA", etc. But is there a commonly-used convention on what type names to use? For example, if you have an integer column, is it better to distinguish between TINYINT, SMALLINT, MEDIUMINT, and BIGINT, or just declare everything as INTEGER? So far, I've been using the following: INTEGER REAL CHAR(n) -- for strings with a known fixed with VARCHAR(n) -- for strings with a known maximum width TEXT -- for all other strings BLOB BOOLEAN DATE -- string in "YYYY-MM-DD" format TIME -- string in "HH:MM:SS" format TIMESTAMP -- string in "YYYY-MM-DD HH:MM:SS" format (Note that the last three are contrary to the type affinity.)

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  • mysql, sqlite database source code

    - by Yang
    hi guys, i know implementing database is a huge topic, but i want to have a basic understanding of how database systems works (e.g. memory management, binary tree, transaction, sql parsing, multi-threading, partitions, etc) by investigating the source code of the database, since there are a few already proven very robust open source databases like mysql, sqlite and so on. however, the code are very complicated and i have no clue where to start. also i find that the old school database textbooks are only explaining the theory, not the implementation details. Can anyone suggest how should i get started and is there any books that emphasis on the technology and techniques of building dbms used in modern database industry? Thank in advance!

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  • Trying to speed up a SQLITE UNION QUERY

    - by user142683
    I have the below SQLITE code SELECT x.t, CASE WHEN S.Status='A' AND M.Nomorebets=0 THEN S.PriceText ELSE '-' END AS Show_Price FROM sb_Market M LEFT OUTER JOIN (select 2010 t union select 2020 t union select 2030 t union select 2040 t union select 2050 t union select 2060 t union select 2070 t ) as x LEFT OUTER JOIN sb_Selection S ON S.MeetingId=M.MeetingId AND S.EventId=M.EventId AND S.MarketId=M.MarketId AND x.t=S.team WHERE M.meetingid=8051 AND M.eventid=3 AND M.Name='Correct Score' With the current interface restrictions, I have to use the above code to ensure that if one selection is missing, that a '-' appears. Some feed would be something like the following SelectionId Name Team Status PriceText =================================== 1 Barney 2010 A 10 2 Jim 2020 A 5 3 Matt 2030 A 6 4 John 2040 A 8 5 Paul 2050 A 15/2 6 Frank 2060 S 10/11 7 Tom 2070 A 15 Is using the above SQL code the quickest & efficient?? Please advise of anything that could help. Messages with updates would be preferable.

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  • SQLite - a smart way to remove and add new objects

    - by Ilya
    Hi, I have a table in my database and I want for each row in my table to have an unique id and to have the rows named sequently. For example: I have 10 rows, each has an id - starting from 0, ending at 9. When I remove a row from a table, lets say - row number 5, there occurs a "hole". And afterwards I add more data, but the "hole" is still there. It is important for me to know exact number of rows and to have at every row data in order to access my table arbitrarily. There is a way in sqlite to do it? Or do I have to manually manage removing and adding of data? Thank you in advance, Ilya.

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  • [C#] SQLite - Creating and changing databases on the fly

    - by Oskar Kjellin
    Today I use SQLite and send a database-file with the project. However I want the database to be created when the user first starts the software. Is there a way to copy the code needed to create a database based on the existing database? The problem is that when a user downloads a new version he might be tricked into copying over his last database and lose the data. I'd like a nice way to check the version of the database and modify it if I need new columns or tables etc. Or, if it does not exist at all, create a new database? I know I can probably make create the code to make the database from the beginning but I want it to be based on the existing database I have created by a gui.

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  • Eager loading vs. many queries with PHP, SQLite

    - by Mike
    I have an application that has an n+1 query problem, but when I implemented a way to load the data eagerly, I found absolutely no performance gain. I do use an identity map, so objects are only created once. Here's a benchmark of ~3000 objects. first query + first object creation: 0.00636100769043 sec. memory usage: 190008 bytes iterate through all objects (queries + objects creation): 1.98003697395 sec. memory usage: 7717116 bytes And here's one when I use eager loading. query: 0.0881109237671 sec. memory usage: 6948004 bytes object creation: 1.91053009033 sec. memory usage: 12650368 bytes iterate through all objects: 1.96605396271 sec. memory usage: 12686836 bytes So my questions are Is SQLite just magically lightning fast when it comes to small queries? (I'm used to working with MySQL.) Does this just seem wrong to anyone? Shouldn't eager loading have given much better performance?

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  • Slow SQLite access on iPhone

    - by georgij
    I have a quite slow data retrieval from a sqlite database on my iPhone and perhaps someone have an alternative idea to explain this. From what I tracked down so far sqlite3_step(statement) is sometimes unusually slow. While retrieving e.g. 50 rows from the database to execute this step takes normally some milliseconds but sometimes it takes several seconds. My database is not small (80MB) and my theory is that the reason is paging. But can someone else think of an other reason for this?

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  • How to transfer SQLite db to web server

    - by Shane
    Hi, I have an application that creates an SQLite database and saves information to it over the course of a day. At the end of the day i want to export this database to a web server. Could anyone point me in the right direction for this? Should I use httppost or put. I have researched this myself online but there seems to be so many different ways to explore. The server side does not exist yet either. I have access to an apache server so i am hoping to use that. Could anyone advise me the best/most simple way to do this? Thanks

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  • sqlite with Perl for Windows; suitable for relocation

    - by Paul Nathan
    I need to set up sqllite for Perl on a Windows box. However - Perl is probably being run over the network from a central server, and I do not know what modules will be available on initial running of my script. I can guarantee Perl 5.8+ (activestate) or Perl 5.10+ (strawberry). Therefore, I need to package sqlite & the associated Perl module(s) in the project directory itself. Having Goggled around, I don't see any immediate zipfile to do this.

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  • SQLite Modify Column

    - by Nathan
    I need to modify a column in a SQLite database but I have to do it programatically due to the database already being in production. From my research I have found that in order to do this I must do the following. Create a new table with new schema Copy data from old table to new table Drop old table Rename new table to old tables name That seems like a ridiculous amount of work for something that should be relatively easy. Is there not an easier way? All I need to do is change a constraint on a existing column and give it a default value.

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  • Next step for Python app using Sqlite db

    - by ChrisC
    I want to write a db program in Python using Sqlite. I have the db table structure planned, and am ready to move to the next step, which I think is to work any bugs out of the db structure. I am totally inexperienced in development except for writing the original db (written in MS Access), and an Intro to C++ class (OOP concepts and console C++ programs). Is it time to test the db structure? If so, what's the best way, and what tool(s) should I use? Thank you.

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