Search Results

Search found 5044 results on 202 pages for 'clausal logic'.

Page 165/202 | < Previous Page | 161 162 163 164 165 166 167 168 169 170 171 172  | Next Page >

  • When are predicates appropriate and what is the best pattern for usage

    - by Maxim Gershkovich
    When are predicates appropriate and what is the best pattern for usage? What are the advantages of predicates? It seems to me like most cases where a predicate can be employed a tight loop would accomplish the same functionality? I don’t see a reusability argument given you will probably only implement a predicate in one method right? They look and feel nice but besides that they seem like you would only employ them when you need a quick hack on the collection classes? UPDATE But why would you be rewriting the tight loop again and again? In my mind/code when it comes to collections I always end up with something like Class Person End Class Class PersonList Inherits List(Of Person) Function FindByName(Name) as Person tight loop.... End Function End Class @Ani By that same logic I could implement the method as such Class PersonList Inherits List(Of Person) Function FindByName(Name) as PersonList End Function Function FindByAge(Age) as PersonList End Function Function FindBySocialSecurityNumber(SocialSecurityNumber) as PersonList End Function End Class And call it as such Dim res as PersonList = MyList.FindByName("Max").FindByAge(25).FindBySocialSecurityNumber(1234) and the result along with the amount of code and its reusability is largely the same, no? I am not arguing just trying to understand.

    Read the article

  • Using JMX classes to notify on events over time

    - by Cincinnati Joe
    I've been looking at JMX for monitoring application and system metrics (partially because MBeans can accessed by various tools such as JConsole). It would seem like the classes included with JMX would be useful for things like notification when metrics have exceeded thresholds. But I'm not sure they fit with the way I want to measure these over a specified time period. For example, let's say I want to notify an admin when the average CPU load is over 95% for more than 5 minutes. Is that something can be done with a GaugeMonitor? From the docs, it doesn't seem quite suited for this, and I'm wondering if instead I should write my own MBean with the necessary logic. A more relevant example is when the login times for users exceed 10s over a period of 5 mins. Slightly different would be the last 20 logins took more than 10s on average. Another case would be when a process crashes 4+ times in an hour. Or the request queue exceeds 15 for 5 mins. Are the JMX Monitor classes useful for this kind of thing?

    Read the article

  • StackPanel loded is not getting fired in.cs page

    - by prince23
    <sdk:DataGridTemplateColumn> <sdk:DataGridTemplateColumn.CellTemplate> <DataTemplate> <StackPanel Loaded ="SPImage_Loaded" Orientation="Horizontal" Background="Transparent" > <Button x:Name="myButton" Click="Btn_Click"> <Image x:Name="imgMarks" " Stretch="None"/> </Button> </StackPanel> </DataTemplate> </sdk:DataGridTemplateColumn.CellTemplate> </sdk:DataGridTemplateColumn> in .cs i have defined the event for stack panel private void SPImage_Loaded(object sender, RoutedEventArgs e) { try { var TargetMarks = sender as StackPanel; Image imgMarks= (Image)TargetScore.FindName("imgMarks"); Marks obj = (Marks )TargetMarks.DataContext; // here marks oject would be containg the details // here if marks.score object value is 1 then bind the image //else // dnt bind the image . that is logic i am trying to do. imgMarks.Source = new BitmapImage(new Uri("/Images/a1.png", UriKind.Relative)); } catch (Exception) { throw; } } any solution on this would be great. is there any better solution to achive this. plz help me out. thank you.

    Read the article

  • Strategies for dealing with Circular references caused by JPA relationships?

    - by ams
    I am trying to partition my application into modules by features packaged into separate jars such as feature-a.jar, feature-b.jar, ... etc. Individual feature jars such as feature-a.jar should contain all the code for a feature a including jpa entities, business logic, rest apis, unit tests, integration test ... etc. The problem I am running into is that bi-directional relationships between JPA entities cause circular references between the jar files. For example Customer entity should be in customer.jar and the Order should be in order.jar but Customer references order and order references customer making it hard to split them into separate jars / eclipse projects. Options I see for dealing with the circular dependencies in JPA entities: Option 1: Put all the entities into one jar / one project Option 2: Don't map certain bi-directianl relationships to avoid circular dependencies across projects. Questions: What rules / principles have you used to decide when to do bi-directional mapping vs. not? Have you been able to break jpa entities into their own projects / jar by features if so how did you avoid the circular dependencies issues?

    Read the article

  • Error while reading custom configuration file(app.config)

    - by Newbie
    I am making a custom configuration in my winform application. (It will represent a country-corrency list) First the CountryList class namespace UtilityMethods { public class CountryList : ConfigurationSection { public CountryList() { // // TODO: Add constructor logic here // } [ConfigurationProperty("CountryCurrency", IsRequired = true)] public Hashtable CountryCurrencies { get { return CountryCurrency.GetCountryCurrency(); } } } } The GetCountryCurrency() method is defined in CountryCurrency class as under namespace UtilityMethods { public static class CountryCurrency { public static Hashtable GetCountryCurrency() { Hashtable ht = new Hashtable(); ht.Add("India", "Rupees"); ht.Add("USA", "Dollar"); return ht; } } } The app.config file looks like <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <section name ="CountryList1" type ="UtilityMethods.CountryList,CountryList,Version=2.0.0.0, Culture=neutral"/> </configSections> <appSettings /> </configuration> And I am calling this from a button_click's event as try { CountryList cList = ConfigurationManager.GetSection("CountryList") as CountryList; Hashtable ht = cList.CountryCurrencies; } catch (Exception ex) { string h = ex.Message; } Upon running the application and clicking on the button I am getting this error Could not load type 'UtilityMethods.CountryList' from assembly 'System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' Please help (dotnet framework : 3.5 Language: C#)

    Read the article

  • What, if any, printable character did a user type based on the values in a given System.Windows.Form

    - by Corey Trager
    As a workaround for a problem, I think I have to handle KeyDown events to get the printable character the user actually typed. KeyDown supplies me with a KeyEventArgs object with the properities KeyCode, KeyData, KeyValue, Modifiers, Alt, Shift, Control. My first attempt was just to consider the KeyCode to be the ascii code, but KeyCode on my keyboard is 46, a period ("."), so I end up printing a period when the user types the delete key. So, I know my logic is inadequate. (For those who are curious, the problem is that I have my own combobox in a DataGridView's control collection and somehow SOME characters I type don't produce the KeyPress and TextChanged ComboBox events. These letters include Q, $, %.... This code will reproduce the problem. Generate a Form App and replace the ctor with this code. Run it, and try typing the letter Q into the two comboxes. public partial class Form1 : Form { ComboBox cmbInGrid; ComboBox cmbNotInGrid; DataGridView grid; public Form1() { InitializeComponent(); grid = new DataGridView(); cmbInGrid = new ComboBox(); cmbNotInGrid = new ComboBox(); cmbInGrid.Items.Add("a"); cmbInGrid.Items.Add("b"); cmbNotInGrid.Items.Add("c"); cmbNotInGrid.Items.Add("d"); this.Controls.Add(cmbNotInGrid); this.Controls.Add(grid); grid.Location = new Point(0, 100); this.grid.Controls.Add(cmbInGrid); }

    Read the article

  • AJAX or a server side framework?

    - by Romansky
    I am working with a friend on building a web site, in general this web site will be a custom web app along with a very custom social network type of thing.. Currently I have a mock-up site that uses simple PHP with AJAX and JSON and JQUERY and I love how it works, I love the way it all fits together. But for a mock-up I did not implement any of the Social Network design patterns such as a login, rating, groups etc.. This brought me to a higher level of decision making requirement, I need to decide if I want to develop all this functionality by hand or use some kind of a framework. I spent this entire day researching, and it would seem that using Drupal and such frameworks will make the Social Network part easy (overlooking the customization requirement for now..) but will make client side Web App development less so. I found some other frameworks that are more developer friendly (customizable) such as Zend and Symfony etc.. but these seem to take allot of the power from the client and implement it in the server side, to me this seems a waste (and an unjustified performance bottleneck) .. Finally I found Aptana Jaxer framework that seems to think the same way I feel. That said it seems a bit under-developed, I didn't find modules for a social network and the community around it seems thin.. (searching Jaxer in StackOverflow returns few results) So other then making server side DB comm a bit simpler it does not help me greatly.. My requirements are a good facility to develop web apps on while containing all the user centric logic usually used for social networks in advance. What would you recommend? EDIT: OK, lats fine tune this question, after considering this abit further, is there a good down loadable source of a social network site in PHP that I can work around in building my web app? (I really like using JQUERY AJAX JSON etc..)

    Read the article

  • Is there a way to load an existing connection string for Linq to SQL from an app.config file?

    - by Brian Surowiec
    I'm running into a really annoying problem with my Linq to SQL project. When I add everything in under the web project everything goes as expected and I can tell it to use my existing connection string stored in the web.config file and the Linq code pulls directly from the ConfigurationManager. This all turns ugly once I move the code into its own project. I’ve created an app.config file, put the connection string in there as it was in the web.config but when I try to add another table in the IDE keeps forcing me to either hardcode the connection string or creates a Settings file and puts it in there, which then adds a new entry into the app.config file with a new name. Is there a way keep my Linq code in its own project yet still refer back to my config file without the IDE continuously hardcoding the connection string or creating the Settings file? I’m converting part of my DAL over to use Linq to SQL so I’d like to use the existing connection string that our old code is using as well as keep the value in a common location, and one spot, instead of in a number of spots. Manually changing the mode to WebSettings instead of AppSettings works untill I try to add a new table, then it goes back to hardcoding the value or recreating the Settings file. I also tried to switch the project type to be a web project and then rename my app.config to web.config and then everything works as I’d like it to. I’m just not sure if there are any downfalls to keeping this as a web project since it really isn't one. The project only contains the Linq to SQL code and an implementation of my repository classes. My project layout looks like this Website -connectionString.config -web.config (refers to connectionString.config) Middle Tier -Business Logic -Repository Interfaces -etc. DAL -Linq to SQL code -Existing SPROC code -connectionString.config (linked from the web poject) -app.config (refers to connectionString.config)

    Read the article

  • How do I write this SQL statement to get the ad and posting? (PHP/MySQL)

    - by ggfan
    I am a little confused on the logic of how to write this SQL statement. When a user clicks on a tag, say HTML, it would display all the posts with HTML as its tag. (a post can have multiple tags) I have three tables: Posting--posting_id, title, detail, etc tags--tagID, tagname postingtag--posting_id, tagID I want to display all the title of the post and the date added. global $dbc; $tagID=$_GET['tagID']; //the GET is set by URL //part I need help with. I need another WHERE statment to get to the posting table $query = "SELECT p.title,p.date_added, t.tagname FROM posting as p, postingtag as pt, tags as t WHERE t.tagID=$tagID"; $data = mysqli_query($dbc, $query); echo '<table>'; echo '<tr><td><b>Title</b></td><td><b>Date Posted</b></td></tr>'; while ($row = mysqli_fetch_array($data)) { echo '<tr><td>'.$row['title'].'</td>'; echo '<td>'.$row['date_added'].'</td></tr>'; } echo '</table>'; }

    Read the article

  • Git: HEAD has disappeared, want to merge it into master.

    - by samgoody
    The top image is the output of: git reflog. The bottom is what GITK in GIT GUI (msysgit) shows me when I look at all branch history. The last few commits do not show on GIT GUI. Why do they not show on GITK (at least as a branch or something)? How do I merge them into master? I gather this happened when I checked out tag 0.42. Why is that not the same as master? (I had tagged the master in its latest state) When I click push, why does the remote repo claim to be up to date.. shouldn't it try to update these commits into whatever branch they are in? The first of the questions is important - I would like to begin to understand what GIT is thinking. It's more oracle than logic at this point. If it makes a difference to see the earlier history, the project is a [pretty powerful] JS color picker that can be viewed here in its entirety.

    Read the article

  • In SQL Server what is most efficient way to compare records to other records for duplicates with in

    - by Glenn
    We have an SQL Server that gets daily imports of data files from clients. This data is interrelated and we are always scrubbing it and having to look for suspect duplicate records between these files. Finding and tagging suspect records can get pretty complicated. We use logic that requires some field values to be the same, allows some field values to differ, and allows a range to be specified for how different certain field values can be. The only way we've found to do it is by using a cursor based process, and it places a heavy burden on the database. So I wanted to ask if there's a more efficient way to do this. I've heard it said that there's almost always a more efficient way to replace cursors with clever JOINS. But I have to admit I'm having a lot of trouble with this one. For a concrete example suppose we have 1 table, an "orders" table, with the following 6 fields. order_id, customer_id product_id, quantity, sale_date, price We want to look through the records to find suspect duplicates on the following example criteria. These get increasingly harder. 1. Records that have the same product_id, sale_date, and quantity but different customer_id's should be marked as suspect duplicates for review. 2. Records that have the same customer_id, product_id, quantity and have sale_dates within five days of each other should be marked as suspect duplicates for review 3. Records that have the same customer_id, product_id, but different quantities within 20 units, and sales dates within five days of each other should be considered suspect. Is it possible to satisfy each one of these criteria with a single SQL Query that uses JOINS? Is this the most efficient way to do this?

    Read the article

  • Android lifecycle of thread-based game

    - by ehehhh
    I ran into a bit of trouble while trying to get my game to work correctly after being put to the background by the user or a phone call for example. My app has a SurfaceView class called GameView, which has the onDraw() method to do all the necessary drawing for my game and two threads - one for calling the onDraw() and one for doing the necessary calculations for the game's logic. I succesfully implemented onPause() and onResume(). (I paused both threads when back button was pressed and resumed them after user cancelled in the AlertDialog.) Now I would like to have the game paused the same way when onStop() gets called. I put both threads on pause and saved my characters location in the savedInstanceState, but when I start my app again, no method gets called (I checked with Logcat). I believe onRestart() should be called first, then onStart() and then onResume(), but none of that happens. What am I doing wrong? (Didn't include any code, because it seems to be a problem of me not understanding the lifecycle, not a problem in code. If it seems necessary, I'll post the parts you request.)

    Read the article

  • Open closed prinicple, problem

    - by Marcus
    Hi, I'm trying to apply OCP to a code snippet I have that in it's current state is really smelly, but I feel I'm not getting all the way to the end. Current code: public abstract class SomeObject {} public class SpecificObject1 : SomeObject {} public class SpecificObject2 : SomeObject {} // Smelly code public class Model { public void Store(SomeObject someObject) { if (someObject is SpecificObject1) {} else if (someObject is SpecificObject2) {} } } That is really ugly, my new approach looks like this: // No so smelly code public class Model { public void Store(SomeObject someObject) { throw new Expception("Not allowed!"); } public void Store(SpecificObject1 someObject) {} public void Store(SpecificObject2 someObject) {} } When a new SomeObject type comes along I must implement how that specific object is stored, this will break OCP cause I need to alter the Model-class. To move the store logic to SomeObject also feels wrong cause then I will violate SRP (?), becuase in this case the SomeObject is almost like a DTO, it's resposibility it not how to know to store itself. If a new implementation to SomeObject comes along who's store implementation is missing I will get a runtime error due to exception in Store method in Model class, it also feels like a code smell. This is because calling code will in the form of IEnumerable<SomeObject> sequence; I will not know the specific types of the sequence objects. I can't seem to grasp the OCP-concept. Anyone has any concrete examples or links that is a bit more than just some Car/Fruit example?

    Read the article

  • What is the best / proper idiom in django for modifying a field during a .save() where you need to o

    - by MDBGuy
    Hi, say I've got: class LogModel(models.Model): message = models.CharField(max_length=512) class Assignment(models.Model): someperson = models.ForeignKey(SomeOtherModel) def save(self, *args, **kwargs): super(Assignment, self).save() old_person = #????? LogModel(message="%s is no longer assigned to %s"%(old_person, self).save() LogModel(message="%s is now assigned to %s"%(self.someperson, self).save() My goal is to save to LogModel some messages about who Assignment was assigned to. Notice that I need to know the old, presave value of this field. I have seen code that suggests, before super().save(), retrieve the instance from the database via primary key and grab the old value from there. This could work, but is a bit messy. In addition, I plan to eventually split this code out of the .save() method via signals - namely pre_save() and post_save(). Trying to use the above logic (Retrieve from the db in pre_save, make the log entry in post_save) seemingly fails here, as pre_save and post_save are two seperate methods. Perhaps in pre_save I can retrieve the old value and stick it on the model as an attribute? I was wondering if there was a common idiom for this. Thanks.

    Read the article

  • What pattern is layered architecture in asp.net ?

    - by haansi
    Hi, I am a asp.net developer and don't know much about patterns and architecture. I will very thankful if you can please guide me here. In my web applications I use 4 layers. Web site project (having web forms + code behind cs files, user controls + code behind cs files, master pages + code behind cs files) CustomTypesLayer a class library (having custom types, enumerations, DTOs, constructers, get, set and validations) BusinessLogicLayer a class library (having all business logic, rules and all calls to DAL functions) DataAccessLayer a class library( having just classes communicating to database.) -My user interface just calls BusinessLogicLayer. BusinessLogicLayer do proecessign in it self and for data it calls DataAccessLayer funtions. -Web forms do not calls directly DAL. -CustomTypesLayer is shared by all layers. Please guide me is this approach a pattern ? I though it may be MVC or MVP but pages have there code behind files as well which are confusing me. If it is no patren is it near to some patren ? pleaes guide thanks

    Read the article

  • tiemout for a function that waits indefiinitely (like listen())

    - by Fantastic Fourier
    Hello, I'm not quite sure if it's possible to do what I'm about to ask so I thought I'd ask. I have a multi-threaded program where threads share a memory block to communicate necessary information. One of the information is termination of threads where threads constantly check for this value and when the value is changed, they know it's time for pthread_exit(). One of the threads contains listen() function and it seems to wait indefinitely. This can be problematic if there are nobody who wants to make connection and the thread needs to exit but it can't check the value whether thread needs to terminate or not since it's stuck on listen() and can't move beyond. while(1) { listen(); ... if(value == 1) pthread_exit(NULL); } My logic is something like that if it helps illustrate my point better. What I thought would solve the problem is to allow listen() to wait for a duration of time and if nothing happens, it moves on to next statement. Unfortunately, none of two args of listen() involves time limit. I'm not even sure if I'm going about the right way with multi-threaded programming, I'm not much experienced at all. So is this a good approach? Perhaps there is a better way to go about it? Thanks for any insightful comments.

    Read the article

  • How Best to Replace PL/SQL with C#?

    - by Mike
    Hi, I write a lot of one-off Oracle SQL queries/reports (in Toad), and sometimes they can get complex, involving lots of unions, joins, and subqueries, and/or requiring dynamic SQL, and/or procedural logic. PL/SQL is custom made for handling these situations, but as a language it does not compare to C#, and even if it did, it's tooling does not, and if even that did, forcing yet another language on the team is something to be avoided whenever possible. Experience has shown me that using SQL for the set based processing, coupled with C# for the procedural processing, is a powerful combination indeed, and far more readable, maintainable and enhanceable than PL/SQL. So, we end up with a number of small C# programs which typically would construct a SQL query string piece by piece and/or run several queries and process them as needed. This kind of code could easily be a disaster, but a good developer can make this work out quite well, and end up with very readable code. So, I don't think it's a bad way to code for smaller DB focused projects. My main question is, how best to create and package all these little C# programs that run ad hoc queries and reports against the database? Right now I create little report objects in a DLL, developed and tested with NUnit, but then I continue to use NUnit as the GUI to select and run them. NUnit just happens to provide a nice GUI for this kind of thing, even after testing has been completed. I'm also interested in suggestions for reporting apps generally. I feel like there is a missing piece or product. The perfect tool would allow writing and running C# inside of Toad, or SQL inside of Visual Studio, along with simple reporting facilities. All ideas will be appreciated, but let's make the assumption that PL/SQL is not the solution.

    Read the article

  • Organising UI code in .NET forms

    - by sb3700
    Hi I'm someone who has taught myself programming, and haven't had any formal training in .NET programming. A while back, I started C# in order to develop a GUI program to control sensors, and the project has blossomed. I was just wondering how best to organise the code, particularly UI code, in my forms. My forms currently are a mess, or at least seem a mess to me. I have a constructor which initialises all the parameters and creates events. I have a giant State property, which updates the Enabled state of all my form control as users progress through the application (ie: disconnected, connected, setup, scanning) controlled by a States enum. I have 3-10 private variables accessed through properties, some of which have side-effects in changing the values of form elements. I have a lot of "UpdateXXX" functions to handle UI elements that depend on other UI elements - ie: if a sensor is changed, then change the baud rate drop down list. They are separated into regions I have a lot of events calling these Update functions I have a background worker which does all the scanning and analysis. My problem is this seems like a mess, particularly the State property, and is getting unmaintainable. Also, my application logic code and UI code are in the same file and to some degree, intermingled which seems wrong and means I need to do a lot of scrolling to find what I need. How do you structure your .net forms? Thanks

    Read the article

  • Generating jquery 'rules' from business model to UI in asp.net mvc

    - by jim
    Hi all, I've had a good look around and am certain that there's no matching question on SO, so here goes. Has anyone created a 'helper' method on their model that generates jquery (or plain javascript) rules validation dynamically, based on the criteria/rules that are contained within the object and taken from a repository (i.e. DB). What i'm thinking of is a discrete set of partial views (and associated models) that have rules at the business logic 'level' and rather than (or in combination with) validating the rule(s) at postback, translating the same rules into tightly focussed jquery methods that work identically at client (js) and server (c#) levels. I can see benefits here re performance. Also, the rules definitions could be created in a single place (in c#) and the jquery generated off of that, thus allowing single edits to update both code streams. I appreciate that there would be limitations imposed by language specific contstraints but the general principle could be quite interesting if used appropriately. I'm also aware that testibility could be an issue when using two different language structures and hoping to achieve similar test outcomes - but those aside... any thoughts or experiences of similar out there?? cheers jimi

    Read the article

  • Inversion of control domain objects construction problem

    - by Andrey
    Hello! As I understand IoC-container is helpful in creation of application-level objects like services and factories. But domain-level objects should be created manually. Spring's manual tells us: "Typically one does not configure fine-grained domain objects in the container, because it is usually the responsibility of DAOs and business logic to create/load domain objects." Well. But what if my domain "fine-grained" object depends on some application-level object. For example I have an UserViewer(User user, UserConstants constants) class. There user is domain object which cannot be injected, but UserViewer also needs UserConstants which is high-level object injected by IoC-container. I want to inject UserConstants from the IoC-container, but I also need a transient runtime parameter User here. What is wrong with the design? Thanks in advance! UPDATE It seems I was not precise enough with my question. What I really need is an example how to do this: create instance of class UserViewer(User user, UserService service), where user is passed as the parameter and service is injected from IoC. If I inject UserViewer viewer then how do I pass user to it? If I create UserViewer viewer manually then how do I pass service to it?

    Read the article

  • is this a design pattern?

    - by Michel
    Hi all, i have to build some financial data report, and for making the calculation, there are a lot of 'if then' situations: if it's a large client, subtract 10%, if it's postal code equals '10101', add 10%, if the day is on a saturday, make a difficult calculation etc. so i once read about this kind of example, and what they did was (hope i remember well) create a class with some base info and make it possible to add all kinds of calculationobjects to it. So to put what i remembered in pseudo code Basecalc bc = new baseCalc(); //put the info in the bc so other objects can do their if bc.Add(new Largecustomercalc()); bc.Add(new PostalcodeCalc()); bc.add(new WeekdayCalc()); the the bc would run the Calc() methods of all of the added Calc objects. As i type this i think all the Calc objects must be able to see the Basecalc properties to correctly perform their calculation logic. So all the if's are in the different Calc objects and not ALL in the Basecalc. does this make sense? I was wondering if this is some kind of design pattern?

    Read the article

  • Grails GORM rarely works in domain classes

    - by Vena
    I have many to many relationship between User and Organization. I want to delete user from all his organizations when the user is being deleted, so this is basically what I came up with: class User { ... def beforeDelete() { def user = User.get(id) Organization.all.each { it.removeFromMembers(user) it.save() } } } This surprisingly doesn't work because User.get(id) returns null even though the user with the given id is in the database, when I look at the log, no sql statement is even executed. So I tried to use load() method insted. ObjectNotFoundException is the result then. So I tried this as I was quite desperate: def user = User.find("from User as u where u.id = ?", [1L]) This, for some reason, works. But now, the line with it.removeFromMembers(user) throws NullPointerException. I tried to put this logic in my UserController and it works! Why is this? Why can't I do this in domain classes? This makes beforeDelete hook (and all the others too) pretty useless.

    Read the article

  • Application Code Redesign to reduce no. of Database Hits from Performance Perspective

    - by Rachel
    Scenario I want to parse a large CSV file and inserts data into the database, csv file has approximately 100K rows of data. Currently I am using fgetcsv to parse through the file row by row and insert data into Database and so right now I am hitting database for each line of data present in csv file so currently database hit count is 100K which is not good from performance point of view. Current Code: public function initiateInserts() { //Open Large CSV File(min 100K rows) for parsing. $this->fin = fopen($file,'r') or die('Cannot open file'); //Parsing Large CSV file to get data and initiate insertion into schema. while (($data=fgetcsv($this->fin,5000,";"))!==FALSE) { $query = "INSERT INTO dt_table (id, code, connectid, connectcode) VALUES (:id, :code, :connectid, :connectcode)"; $stmt = $this->prepare($query); // Then, for each line : bind the parameters $stmt->bindValue(':id', $data[0], PDO::PARAM_INT); $stmt->bindValue(':code', $data[1], PDO::PARAM_INT); $stmt->bindValue(':connectid', $data[2], PDO::PARAM_INT); $stmt->bindValue(':connectcode', $data[3], PDO::PARAM_INT); // Execute the statement $stmt->execute(); $this->checkForErrors($stmt); } } I am looking for a way wherein instead of hitting Database for every row of data, I can prepare the query and than hit it once and populate Database with the inserts. Any Suggestions !!! Note: This is the exact sample code that I am using but CSV file has more no. of field and not only id, code, connectid and connectcode but I wanted to make sure that I am able to explain the logic and so have used this sample code here. Thanks !!!

    Read the article

  • Django: returning a selection of fields from a model based on their values?

    - by AP257
    I am working with some data over which I have little control. I'd like to return ONLY the fields of my model that aren't certain 'uninteresting' values (e.g. '0', 'X' or '-'), and access them individually in the template. My model is like this: class Manors(models.Model): structidx = models.IntegerField(primary_key=True, verbose_name="ID") hills = models.CharField(max_length=100, null=True, blank=True, verbose_name="Number of fields") In my template, I return a QuerySet of Manors, and I'd like to output something like this if the hills field isn't uninteresting: {% for manor in manors %} {% if manor.hills %}<li>Hills blah blah: {{ manor.hills }}</li>{% endif %} {% endfor %} I want to avoid too much logic in the template. Ideally, the manor object would simply not return with the uninteresting fields attached, then I could just do {% if manor.hills %}. I tried writing a model method that returns a dictionary of the interesting values, like this: def get_field_dictionary(self): interesting_fields = {} for field in Manors._meta.fields: if field.value_to_string(self) != "N" and field.value_to_string(self) != "0" and field.value_to_string(self) != "-" and field.value_to_string(self) != "X": interesting_fields[field.name] = field.value_to_string(self) return interesting_fields But I don't know how to access individual values of the dictionary in the template: {% if manor.get_field_dictionary['hills'] %}<li>Hills blah blah: {{ manor.get_field_dictionary['hills'] }}</li>{% endif %} gives a TemplateSyntaxError. Is there a better way to do this?

    Read the article

  • Mutually beneficial IP/copyright clauses for contract-based freelance work

    - by Nathan de Vries
    I have a copyright section in the contract I give to my clients stating that I retain copyright on any works produced during my work for them as an independent contractor. This is most definitely not intended to place arbitrary restrictions on my clients, but rather to maintain my ability to decide on how the software I create is licensed and distributed. Almost every project I work on results in at least one part of it being released as open source. Every project I work on makes use of third-party software released in the same fashion, so returning the favour is something I would like to continue doing. Unfortunately, the contract is not so clear when it comes to defining the rights of the client in the use of said software. I mention that the code will be licensed to them, but do not mention specifics about exclusivity, ability to produce derivatives etc. As such, a client has raised concerns about the copyright section of my contract, and has suggested that I reword it such that all copyrights are transferred entirely to the client on final payment for the project. This will almost certainly reduce my ability to distribute the software I have created; I would much prefer to find a more mutually beneficial agreement where both our concerns are appeased. Are there any tried and true approaches to licensing software in this kind of situation? To summarise: I want to maintain the ability to license (parts of) the software under my own terms, independently of my relationship with the client; with some guarantee to the client that no trade-secrets or critical business logic will be shared; giving them the ability to re-use my code in their future projects; but not necessarily letting them sell it (I'm not sure about this, though...what happens if they sell their business and the software along with it?) I realise that everyone's feedback is going to be prefixed with "IANAL", however I appreciate any thoughts you might have on the matter.

    Read the article

< Previous Page | 161 162 163 164 165 166 167 168 169 170 171 172  | Next Page >