Search Results

Search found 20401 results on 817 pages for 'null coalescing operator'.

Page 409/817 | < Previous Page | 405 406 407 408 409 410 411 412 413 414 415 416  | Next Page >

  • How to implement a Linked List in Java?

    - by nbarraille
    Hello! I am trying to implement a simple HashTable in Java that uses a Linked List for collision resolution, which is pretty easy to do in C, but I don't know how to do it in Java, as you can't use pointers... First, I know that those structures are already implemented in Java, I'm not planning on using it, just training here... So I created an element, which is a string and a pointer to the next Element: public class Element{ private String s; private Element next; public Element(String s){ this.s = s; this.next = null; } public void setNext(Element e){ this.next = e; } public String getString(){ return this.s; } public Element getNext(){ return this.next; } @Override public String toString() { return "[" + s + "] => "; } } Of course, my HashTable has an array of Element to stock the data: public class CustomHashTable { private Element[] data; Here is my problem: For example I want to implement a method that adds an element AT THE END of the linked List (I know it would have been simpler and more efficient to insert the element at the beginning of the list, but again, this is only for training purposes). How do I do that without pointer? Here is my code (which could work if e was a pointer...): public void add(String s){ int index = hash(s) % data.length; System.out.println("Adding at index: " + index); Element e = this.data[index]; while(e != null){ e = e.getNext(); } e = new Element(s); } Thanks!

    Read the article

  • calling a trim method in actionscript 2.0

    - by user151013
    Hi I Got a notnull function for a text field as below private function valStringNotNull( val:String ) :Boolean { if ( String(val).length <= 0 ) { _errorCode = "StringNull"; return false; } _errorCode = "NoError"; return true; } and this function is being called here var pCnt:Number = 0; _validateParams[pCnt++] = { type: "notNull", input: win.firstNameInput , isSendData:true, dataName:"firstName"}; _validateParams[pCnt++] = { type: "notNull", input: win.lastNameInput, isSendData:true, dataName:"lastName"}; _validateParams[pCnt++] = { type: "noValidation", input: roleCombo, isSendData:true, dataName:"role" }; Selection.setFocus(win.firstNameInput); and for the not null I defined this way private function validateCases ( param:Object ) :Boolean { _errorObj = param.input || param.input1; switch( param.type ) { case "notNull": return valStringNotNull( param.input.text ); break; } } but as you see as I defined the length should be greater than zero its taking even a space as an input and displaying blank white space in my text field so I got a trim function as below public function ltrim(input:String):String { var size:Number = input.length; for(var i:Number = 0; i < size; i++) { if(input.charCodeAt(i) > 32) { return input.substring(i); } } return ""; } and I need to call this trim function before my not null function so that it trims off all the leftside white space but as I am very new to flash can some one help me how to keep this trim function before the notnull function.Can some one please help me with this please

    Read the article

  • What does it mean when a Perl method returns a "hashref"?

    - by Uri
    I'm trying to decrypt a Perl code which I'm not familiar with, somehow related to HashRef. I'm using Amazon::S3, but my question is a general Perl question. See the code below: use Amazon::S3; my $s3 = Amazon::S3->new( ... ); my $response = $s3->buckets; Documentation (here) sais, about s3-buckets: Returns undef on error, else HASHREF of results The following line is working for me, but I don't understand why: for $b in ( @ { $response->{buckets} } ) { print "bucket: " . $b->bucket . "\n"; } I'm Puzzled by each operator on the first line. What type exactly are $response, $respone->{bucket}. Looks like the expression within the for is an array, but I don't understand this syntax: @{ ... }?

    Read the article

  • guarantee child records either in one table or another, but not both?

    - by user151841
    I have a table with two child tables. For each record in the parent table, I want one and only one record in one of the child tables -- not one in each, not none. How to I define that? Here's the backstory. Feel free to criticize this implementation, but please answer the question above, because this isn't the only time I've encountered it: I have a database that holds data pertaining to user surveys. It was originally designed with one authentication method for starting a survey. Since then, requirements have changed, and now there are two different ways someone could sign on to start a survey. Originally I captured the authentication token in a column in the survey table. Since requirements changed, there are three other bits of data that I want to capture in authentication. So for each record in the survey table, I'm either going to have one token, or a set of three. All four of these are of different types, so my thought was, instead of having four columns where either one is going to be null, or three are going to be null ( or even worse, a bad mashup of either of those scenarios ), I would have two child tables, one for holding the single authentication token, the other for holding the three. Problem is, I don't know offhand how to define that in DDL. I'm using MySQL, so maybe there's a feature that MySQL doesn't implement that lets me do this.

    Read the article

  • Timer C#. Start, stop, and get the amount of time between the calls

    - by user1886060
    I'm writing UDP chat with reliable data transfer. I need to start a timer when a packet is sent, and stop it as soon it receives an answer from the server(ACK- acknowledgment). Here is my code: private void sendButton_Click(object sender, EventArgs e) { Packet snd = new Packet(ack, textBox1.Text.Trim()); textBox1.Text = string.Empty; Smsg = snd.GetDataStream();//convert message into array of bytes to send. while (true) { try { // Here I need to Start a timer! clientSock.SendTo(Smsg, servEP); clientSock.ReceiveFrom(Rmsg, ref servEP); //Here I need to stop a timer and get elapsed amount of time. Packet rcv = new Packet(Rmsg); if (Rmsg != null && rcv.ACK01 != ack) continue; if (Rmsg != null && rcv.ACK01 == ack) { this.displayMessageDelegate("ack is received :"+ack); ChangeAck(ack); break; } Thank you.

    Read the article

  • C++: Vector3 type "wall" ?

    - by anon
    Say I have: class Vector3 { float x, y, z; ... bunch of cuntions .. static operator+(const Vector3&, const Vector3); }; Now, suppose I want to have classes: Position, Velocity, that are exactly like Vector3 (basically, I want typedef Vector3 Position; typedef Vector3 Velocity; Except, given: Position position; Vector3 vector3; Velocity velocity; I want to make sure the following can't happen: position + vector3; vector3 + velocity; velocity + position; What is the best way to achieve this?

    Read the article

  • More than one JPanel in a Frame / having a brackground Image and another Layer with Components on the top

    - by user1905203
    I've got a JFrame with a JPanel in which there is a JLabel with an ImageIcon(). Everything's working perfectly, problem is i now want to add another JPanel with all the other stuff like buttons and so on to the JFrame. But it still shows the background Image on top and nothing with the second JPanel. Can someone help me? Here is an extract of my code: JFrame window = new JFrame("Http Download"); /* * Background Section */ JPanel panel1 = new JPanel(); JLabel lbl1 = new JLabel(); /* * Component Section */ JPanel panel2 = new JPanel(); JLabel lbl2 = new JLabel(); /* * Dimension Section */ Dimension windowSize = new Dimension(800, 600); Dimension screen = Toolkit.getDefaultToolkit().getScreenSize(); public HTTPDownloadGUI() { window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); panel1.setLayout(null); panel1.setSize(windowSize); panel1.setOpaque(false); panel2.setLayout(null); panel2.setSize(windowSize); panel2.setOpaque(false); lbl1.setSize(windowSize); lbl1.setLocation(0, 0); lbl1.setIcon(new ImageIcon(getClass().getResource("bg1.png"))); panel1.add(lbl1); lbl2.setBounds(0, 0, 100, 100); //lbl2.setIcon(new ImageIcon(getClass().getResource("bg2.png"))); lbl2.setBackground(Color.GREEN); panel2.add(lbl2); panel1.add(panel2); window.add(panel1); int X = (screen.width / 2) - (windowSize.width / 2); int Y = (screen.height / 2) - (windowSize.height / 2); window.setBounds(X,Y , windowSize.width, windowSize.height); window.setVisible(true); }

    Read the article

  • Ajax request ERROR on IE

    - by tinti
    Hello all! I have a small problem on IE browser (actually on Google Chrome too) I have this js code function createDoc(url) { var xhttp = ajaxRequest(); var currentLocationBase = window.location.href; currentLocationBase = currentLocationBase.substr(0,currentLocationBase.lastIndexOf("/") + 1); var u = currentLocationBase + url; xhttp.open("GET", u, false); xhttp.send(null); var xml = xhttp.responseXML; return xml; } /** * Builds an AJAX reques handler. * * @return The handler. */ function ajaxRequest() { var xhttp = null; if (window.XMLHttpRequest) { xhttp = new XMLHttpRequest(); } else if (window.ActiveXObject){ // Internet Explorer 5/6 xhttp = new ActiveXObject("Microsoft.XMLHTTP"); } else { } return xhttp; } In Firefox this code works great, but not in IE and Google Chrome Seems that the error is given at the line xhttp.open("GET", u, false); Can anyone help me to understand what i'm doing wrong? Thanks

    Read the article

  • Reverse wildcard search in codeigniter

    - by Andy Platt
    I am implementing a snippet-based content management system into my current project. Snippets can be associated with a page either by exact match of the full url falling back to a wildcard match on a partial url or finally a default snippet. To implement this I have a created table of page associations with a wildcard flag, the system first checks the current url against the non-wildcard associations and if it doesn't find a match it checks against the partial url's where the wildcard flag is set. In order to achieve this I am getting all the partial url's from the database and putting them into an array then walking the array to check for a match against the current url: protected function _check_wildcard($url = NULL) { if($url) { $q = $this->db->where('wildcard' ,'Y') ->from('content') ->get(); $wildcards = $q->result_array(); foreach($wildcards AS $wildcard) { if(strpos($url,$wildcard['url']) > 0) { return $wildcard['snipppet_id']; } } } else { return NULL; } } Can anyone suggest a better way to do this - preferably one that doesn't involve having to constantly download the full list of all the wildcards each time I load a page as I am afraid that this will have a negative effect on the scalability of the system down the line?

    Read the article

  • C# Custom user settings class not saving

    - by Zenox
    I have the following class: [Serializable] [XmlRoot ( ElementName = "TextData", IsNullable = false)] public class TextData { private System.Drawing.Font fontColor; [XmlAttribute ( AttributeName = "Font" )] public System.Drawing.Font Font { get; set; } [XmlAttribute ( AttributeName = "FontColor" )] public System.Drawing.Color FontColor { get; set; } [XmlAttribute ( AttributeName = "Text" )] public string Text { get; set; } public TextData ( ) { } // End of TextData } // End of TextData And Im attempting to save it with the following code: // Create our font dialog FontDialog fontDialog = new FontDialog ( ); fontDialog.ShowColor = true; // Display the dialog and check for an ok if ( DialogResult.OK == fontDialog.ShowDialog ( ) ) { // Save our changes for the font settings if ( null == Properties.Settings.Default.MainHeadlineTextData ) { Properties.Settings.Default.MainHeadlineTextData = new TextData ( ); } Properties.Settings.Default.MainHeadlineTextData.Font = fontDialog.Font; Properties.Settings.Default.MainHeadlineTextData.FontColor = fontDialog.Color; Properties.Settings.Default.Save ( ); } Everytime I load the the application, the Properties.Settings.Default.MainHeadlineTextData is still null. Saving does not seem to take effect. I read on another post that the class must be public and it is. Any ideas why this would not be working properly?

    Read the article

  • Linq2Sql - attempting to update but the Set statement in sql is empty

    - by MrTortoise
    This is weird ... done updates loads of times before but cannot spot why this is different. I have a client class from the dbml I added a method called update public void UpdateSingle() { L2SDataContext dc = new L2SDataContext(); Client c = dc.Clients.Single<Client>(p => p.ID == this.ID); c.CopyToMe(this); c.updatedOn = DateTime.Now; dc.SubmitChanges(); dc.Dispose(); } The CopytoMe method public void CopyToMe(Client theObject) { if (ID != theObject.ID) { ID = theObject.ID; } /// this is redundant as generated code checks field for a change. deleted = theObject.deleted; deletedBy = theObject.deletedBy; deletedOn = theObject.deletedOn; insertedBy = theObject.insertedBy; insertedOn = theObject.insertedOn; name = theObject.name; updatedBy = theObject.updatedBy; updatedOn = theObject.updatedOn; } Im taking a client that was selected, changing its name and then calling this update method. The generated sql is as follows exec sp_executesql N'UPDATE [dbo].[tblClient] SET WHERE ([ID] = @p0) AND ([name] = @p1) AND ([insertedOn] = @p2) AND ([insertedBy] = @p3) AND ([updatedOn] = @p4) AND ([updatedBy] = @p5) AND ([deletedOn] IS NULL) AND ([deletedBy] IS NULL) AND (NOT ([deleted] = 1))',N'@p0 int,@p1 varchar(8000),@p2 datetime,@p3 int,@p4 datetime,@p5 int',@p0=103,@p1='UnitTestClient',@p2=''2010-05-17 11:33:22:520'',@p3=3,@p4=''2010-05-17 11:33:22:520'',@p5=3 I have no idea why this is not working ... used this kind of select object, set field to new value submit the selected object pattern many times and not had this problem. there is also nothing obviously wrong with the dbml - although this is probably a false statement any ideas?

    Read the article

  • How do I put logic in a View a scope or method in a Model?

    - by Angela
    I have the following in the view: <% unless contact_email.statuses.empty?%> (<%= contact_email.statuses.find(:last).status%>) <% end %> contact_email is an instance of a specific model. Could I do something like this? class ContactEmail < ActiveRecord::Base attr_accessible :contact_id, :email_id, :status, :subject, :body, :date_created, :date_sent def status unless contact_email.statuses.empty? contact_email.statuses.find(:last).status end end end is there a better way to do this? is there a way to use the || operator for a default if empty? Basically, I would like to be able to do the following in the View: <%= contact_email.status = IF there is a value, then display it, if not, show nothing.

    Read the article

  • Mobile web apps - Is this the right approach?

    - by Pasta
    I need to build a cross platform mobile app (iphone, android, etc). The app is for a company like a cellular operator (Tmobile, ATT). The app needs to do the following: Show previous bills (cached so that it does not have to download everytime) Need an internet connection to download newer bills, view recent data, etc. Can I build a mobile web app to handle this? I understand that there is offline storage and iPhone has good support for web apps (full screen, good icons, offline, etc). Will a web app be the best approach to take as the app requires to be online? The app will not be used by lots of people, just customers of the website who don't want to use an existing website. We are all web developers and a mobile web app looks like the best way to approach this.

    Read the article

  • calling a java class in a servlet

    - by kawtousse
    hi, in my servlet i called an instance of a class.java( a class that construct an html table) in order to create this table in my jsp. the servlet is like the following: String report=request.getParameter("selrep"); String datev=request.getParameter("datepicker"); String op=request.getParameter("operator"); String batch =request.getParameter("selbatch"); System.out.println("report kind was:"+report); System.out.println("date was:"+datev); System.out.println("operator:"+op); System.out.println("batch:"+batch); if(report.equalsIgnoreCase("Report Denied")) { DeniedReportDisplay rd = new DeniedReportDisplay(); rd.ConstruireReport(); } else if(report.equalsIgnoreCase("Report Locked")) { LockedReportDisplay rl = new LockedReportDisplay(); rl.ConstruireReport(); } request.getRequestDispatcher("EspaceValidation.jsp").forward(request, response); in my jsp i can not display this table even empty or full. note: exemple a class that construct denied Report has this structure: /*constructeur*/ public DeniedReportDisplay() {} /*Methodes*/ @SuppressWarnings("unchecked") public StringBuffer ConstruireReport() { StringBuffer retour=new StringBuffer(); int i = 0; retour.append("<table border = 1 width=900 id=sheet align=left>"); retour.append("<tr bgcolor=#0099FF>" ); retour.append("<label> Denied Report</label>"); retour.append("</tr>"); retour.append("<tr>"); String[] nomCols ={"Nom","Prenom","trackingDate","activity","projectcode","WAName","taskCode","timeSpent","PercentTaskComplete","Comment"}; //String HQL_QUERY = null; for(i=0;i< nomCols.length;i++) { retour.append(("<td bgcolor=#0066CC>")+ nomCols[i] + "</td>"); } retour.append("</tr>"); retour.append("<tr>"); try { s= HibernateUtil.currentSession(); tx=s.beginTransaction(); Query query = s.createQuery("select opcemployees.Nom,opcemployees.Prenom,dailytimesheet.TrackingDate,dailytimesheet.Activity," + "dailytimesheet.ProjectCode,dailytimesheet.WAName,dailytimesheet.TaskCode," + "dailytimesheet.TimeSpent,dailytimesheet.PercentTaskComplete from Opcemployees opcemployees,Dailytimesheet dailytimesheet " + "where opcemployees.Matricule=dailytimesheet.Matricule and dailytimesheet.Etat=3 " + "group by opcemployees.Nom,opcemployees.Prenom" ); for(Iterator it=query.iterate();it.hasNext();) { if(it.hasNext()){ Object[] row = (Object[]) it.next(); retour.append("<td>" +row [0]+ "</td>");//Nom retour.append("<td>" + row [1] + "</td>");//Prenom retour.append("<td>" + row [2] + "</td>");//trackingdate retour.append("<td>" + row [3]+ "</td>");//activity retour.append("<td>" + row [4] +"</td>");//projectcode retour.append("<td>" + row [5]+ "</td>");//waname retour.append("<td>" + row [6] + "</td>");//taskcode retour.append("<td>" + row [7] + "</td>");//timespent retour.append("<td>" + row [8] + "</td>");//perecnttaskcomplete retour.append("<td><input type=text /></td>");//case de commentaire } retour.append("</tr>"); } //terminer la table. retour.append ("</table>"); tx.commit(); } catch (HibernateException e) { retour.append ("</table><H1>ERREUR:</H1>" +e.getMessage()); e.printStackTrace(); } return retour; } thanks for help.

    Read the article

  • How to use strtok in C properly so there is no memory leak?

    - by user246392
    I am somewhat confused by what happens when you call strtok on a char pointer in C. I know that it modifies the contents of the string, so if I call strtok on a variable named 'line', its content will change. Assume I follow the bellow approach: void function myFunc(char* line) { // get a pointer to the original memory block char* garbageLine = line; // Do some work // Call strtok on 'line' multiple times until it returns NULL // Do more work free(garbageLine); } Further assume that 'line' is malloced before it is passed to myFunc. Am I supposed to free the original string after using strtok or does it do the job for us? Also, what happens if 'line' is not malloced and I attempt to use the function above? Is it safer to do the following instead? (Assume the programmer won't call free if he knows the line is not malloced) Invocation char* garbageLine = line; myFunc(line); free(garbageLine); Function definition void function myFunc(char* line) { // Do some work // Call strtok on 'line' multiple times until it returns NULL // Do more work }

    Read the article

  • Clarification of a some code

    - by Legend
    I have come across a website that appears to use Ajax but does not include any js file except one file called ajax.js which has the following: function run(c, f, b, a, d) { var e = null; if (b && f) { document.getElementById(b).innerHTML = f } if (window.XMLHttpRequest) { e = new XMLHttpRequest() } else { if (window.ActiveXObject) { e = new ActiveXObject(Microsoft.XMLHTTP) } } e.onreadystatechange = function () { if (e.readyState == 4) { if (e.status == 200 || e.statusText == "OK") { if (b) { document.getElementById(b).innerHTML = e.responseText } if (a) { setTimeout(a, 0) } } else { console.log("AJAX Error: " + e.status + " | " + e.statusText); if (b && d != 1) { document.getElementById(b).innerHTML = "AJAX Error. Please try refreshing." } } } }; e.open("GET", c, true); e.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); e.send(null) } Like you might have guessed, the way it issues queries inside the page with queries like this: run('page.php',loadingText,'ajax-test', 'LoadSamples()'); I must admit that this is the first time I've seen a page from which I could not figure how things are being done. I have a few questions: Is this Server-Side Ajax or something similar? If not, can someone clarify what exactly is this? Why does one use this? Is it for hiding the design details? (which are otherwise revealed in plain text by javascript) How difficult would it be to convert my existing application into this design pattern? (maybe a subjective question but any short suggestion will do) Any suggestions?

    Read the article

  • Kill process started with System.Diagnostic.Process.Start("FileName")

    - by PedroC88
    Hello; I am trying to create an app that will perform actions on specific times (much like the Windows Task Scheduler). I am currently using Process.Start() to lunch the file (or exe) required by the task. I am initiating a process by calling a file (an .mp3) and the process starts WMP (since it is the default application), so far so good. Now I wan't to kill that process. I know that it is normal behavior for the Process.Start(string, string) to return nothing (null in C#) in this case. So I am asking how can i close WMP when I called it through Process.Start(string, string)?? Edit: Please note that I am not opening WMP directly with Process.Start() and this is the line with which I run the process: VB: Me._procs.Add(Process.Start(Me._procInfo)) C#: this._procs.Add(Process.Start(this._procInfo)) _procInfo is a ProcessStartInfo instance. _procInfo.FileName is "C:\route\myFile.mp3". That is why WMP opens. In any case, all of the Start() methods, except for the instance-one which returns a boolean, return nothing (null in C#), because WMP is not the process that was directly created (please note that WMP is run and the song does play).

    Read the article

  • Switching from php to python

    - by ts
    Hello I am trying to make a list of things which can be difficult/surprising to someone who is changing language from PHP to Python. so far i have rather short list: forget require / include, learn import (this was most difficult to me - to understand package - module - class - object hierarchy and its mapping to filesystem) you can't just upload file on server to have webpage (-mod_python, wsgi etc) learn the python way for use variable class names (new $class() vs import + getattr) / operator in python 2.x and all float-related horrors those were difficult to me, it takes few days before mind adapts a new paradigm after i found that there is few other areas which could be challenging for someone with (too) many years of php: everything is an object you have to live with exceptions array vs list, set, dictionary, tuple ... learn (effective) list comprehensions learn generators any other ideas / personal experiences ?

    Read the article

  • Implementing an iterator over binary tree using C++ 11

    - by user1459339
    I would like to create an iterator over the binary tree so as to be able to use range-based for loop. I understand I ought to implement the begin() and end() function first. Begin should probably point to the root. According to the specification, however, the end() functions returns "the element following the last valid element". Which element (node) is that? Would it not be illegal to point to some "invalid" place? The other thing is the operator++. What is the best way to return "next" element in tree? I just need some advice to begin with this programming.

    Read the article

  • How to know if the argument that is passed to the function is a class, union or enum in c++?

    - by Narek
    I want to define an operator<< for all enums, to cout the value and print that it is an enum like this: code: enum AnyEnum{A,B,C}; AnyEnum enm = A; cout << enm <<endl; output: This is an enum which has a value equal to 0 I know a way of doing this with Boost library by using is_enum struct. But I don’t understand how it works. So that's why, in general, I am interested how to identify if the veriable is a class type, union type or an enum (in compile time).

    Read the article

  • What's the simplest way of defining lexicographic comparison for elements of a class?

    - by the_mandrill
    If I have a class that I want to be able to sort (ie support a less-than concept), and it has several data items such that I need to do lexicographic ordering then I need something like this: struct MyData { string surname; string forename; bool operator<(const MyData& other) const { return surname < other.surname || (surname==other.surname && forename < other.forename); } }; This becomes pretty unmanageable for anything with more than 2 data members. Are there any simpler ways of achieving it? The data members may be any Comparable class.

    Read the article

  • Query to bring count from comma seperated Value

    - by Mugil
    I have Two Tables One for Storing Products and Other for Storing Orders List. CREATE TABLE ProductsList(ProductId INT NOT NULL PRIMARY KEY, ProductName VARCHAR(50)) INSERT INTO ProductsList(ProductId, ProductName) VALUES(1,'Product A'), (2,'Product B'), (3,'Product C'), (4,'Product D'), (5,'Product E'), (6,'Product F'), (7,'Product G'), (8,'Product H'), (9,'Product I'), (10,'Product J'); CREATE TABLE OrderList(OrderId INT NOT NULL PRIMARY KEY AUTO_INCREMENT, EmailId VARCHAR(50), CSVProductIds VARCHAR(50)) SELECT * FROM OrderList INSERT INTO OrderList(EmailId, CSVProductIds) VALUES('[email protected]', '2,4,1,5,7'), ('[email protected]', '5,7,4'), ('[email protected]', '2'), ('[email protected]', '8,9'), ('[email protected]', '4,5,9'), ('[email protected]', '1,2,3'), ('[email protected]', '9,10'), ('[email protected]', '1,5'); Output ItemName NoOfOrders Product A 4 Product B 3 Product C 1 Product D 3 Product E 4 Product F 0 Product G 2 Product H 1 Product I 2 Product J 1 The Order List Stores the ItemsId as Comma separated value for every customer who places order.Like this i am having more than 40k Records in my dB table Now I am assigned with a task of creating report in which I should display Items and No of People ordered Items as Shown Below I Used Query as below in my PHP to bring the Orders One By One and storing in array. SELECT COUNT(PL.EmailId) FROM OrderList PL WHERE CSVProductIds LIKE '2' OR CSVProductIds LIKE '%,2,%' OR CSVProductIds LIKE '%,2' OR CSVProductIds LIKE '2,%'; 1.Is it possible to get the same out put by using Single Query 2.Does using a like in mysql query slows down the dB when the table has more no of records i.e 40k rows

    Read the article

  • C++ Iterators and inheritance

    - by jomnis
    Have a quick question about what would be the best way to implement iterators in the following: Say I have a templated base class 'List' and two subclasses "ListImpl1" and "ListImpl2". The basic requirement of the base class is to be iterable i.e. I can do: for(List<T>::iterator it = list->begin(); it != list->end(); it++){ ... } I also want to allow iterator addition e.g.: for(List<T>::iterator it = list->begin()+5; it != list->end(); it++){ ... } So the problem is that the implementation of the iterator for ListImpl1 will be different to that for ListImpl2. I got around this by using a wrapper ListIterator containing a pointer to a ListIteratorImpl with subclasses ListIteratorImpl2 and ListIteratorImpl2, but it's all getting pretty messy, especially when you need to implement operator+ in the ListIterator. Any thoughts on a better design to get around these issues?

    Read the article

  • Implementing search functionality with multiple optional parameters against database table.

    - by quarkX
    Hello, I would like to check if there is a preferred design pattern for implementing search functionality with multiple optional parameters against database table where the access to the database should be only via stored procedures. The targeted platform is .Net with SQL 2005, 2008 backend, but I think this is pretty generic problem. For example, we have customer table and we want to provide search functionality to the UI for different parameters, like customer Type, customer State, customer Zip, etc., and all of them are optional and can be selected in any combinations. In other words, the user can search by customerType only or by customerType, customerZIp or any other possible combinations. There are several available design approaches, but all of them have some disadvantages and I would like to ask if there is a preferred design among them or if there is another approach. Generate sql where clause sql statement dynamically in the business tier, based on the search request from the UI, and pass it to a stored procedure as parameter. Something like @Where = ‘where CustomerZip = 111111’ Inside the stored procedure generate dynamic sql statement and execute it with sp_executesql. Disadvantage: dynamic sql, sql injection Implement a stored procedure with multiple input parameters, representing the search fields from the UI, and use the following construction for selecting the records only for the requested fields in the where statement. WHERE (CustomerType = @CustomerType OR @CustomerType is null ) AND (CustomerZip = @CustomerZip OR @CustomerZip is null ) AND ………………………………………… Disadvantage: possible performance issue for the sql. 3.Implement separate stored procedure for each search parameter combinations. Disadvantage: The number of stored procedures will increase rapidly with the increase of the search parameters, repeated code.

    Read the article

  • Sqlite3 INSERT INTO Question × 377

    - by user316717
    Hi, My 1st post. I am creating an exercise app that will record the weight used and the number of "reps" the user did in 4 "Sets" per day over a period of 7 days so the user may view their progress. I have built the database table named FIELDS with 2 columns ROW and FIELD_DATA and I can use the code below to load the data into the db. But the code has a sql statement that says, INSERT OR REPLACE INTO FIELDS (ROW, FIELD_DATA)VALUES (%d, '%@'); When I change the statment to: INSERT INTO FIELDS (ROW, FIELD_DATA)VALUES (%d, '%@'); Nothing happens. That is no data is recorded in the db. Below is the code: #define kFilname @"StData.sqlite3" - (NSString *)dataFilePath { NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; return [documentsDirectory stringByAppendingPathComponent:kFilname]; } -(IBAction)saveData:(id)sender; { for (int i = 1; i <= 8; i++) { NSString *fieldName = [[NSString alloc]initWithFormat:@"field%d", i]; UITextField *field = [self valueForKey:fieldName]; [fieldName release]; NSString *insert = [[NSString alloc] initWithFormat: @"INSERT OR REPLACE INTO FIELDS (ROW, FIELD_DATA) VALUES (%d, '%@');",i, field.text]; // sqlite3_stmt *stmt; char *errorMsg; if (sqlite3_exec (database, [insert UTF8String], NULL, NULL, &errorMsg) != SQLITE_OK) { // NSAssert1(0, @"Error updating table: %s", errorMsg); sqlite3_free(errorMsg); } } sqlite3_close(database); } So how do I modify the code to do what I want? It seemed like a simple sql statement change at first but obviously there must be more. I am new to Objective-C and iPhone programming. I am not new to using sql statements as I have been creating web apps in ASP for a number of years. Any help will be greatly appreciated, this is driving me nuts! Thanks in advance Dave

    Read the article

< Previous Page | 405 406 407 408 409 410 411 412 413 414 415 416  | Next Page >