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  • Database error when deleting entry in my rails app.

    - by Danny McClelland
    Hi Everyone...again! I have almost everything in my Rails app working, with the exception of detroying entries. I can destroy entries for companies but not kases and people. The following error show when trying to do so: SQLite3::SQLException: no such column: kases_people.kase_id: SELECT * FROM "kases" INNER JOIN "kases_people" ON "kases".id = "kases_people".kase_id WHERE ("kases_people".person_id = 5 ) I suspect this is an error with the party model for the has_many :through associations that I dont fully understand. You can find an up to date version of the app at www.github.com/dannyweb/surveycontrol Thanks, Danny

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  • Optimizing ROW_NUMBER() in SQL Server

    - by BlueRaja
    We have a number of machines which record data into a database at sporadic intervals. For each record, I'd like to obtain the time period between this recording and the previous recording. I can do this using ROW_NUMBER as follows: WITH TempTable AS ( SELECT *, ROW_NUMBER() OVER (PARTITION BY Machine_ID ORDER BY Date_Time) AS Ordering FROM dbo.DataTable ) SELECT [Current].*, Previous.Date_Time AS PreviousDateTime FROM TempTable AS [Current] INNER JOIN TempTable AS Previous ON [Current].Machine_ID = Previous.Machine_ID AND Previous.Ordering = [Current].Ordering + 1 The problem is, it goes really slow (several minutes on a table with about 10k entries) - I tried creating separate indicies on Machine_ID and Date_Time, and a single joined-index, but nothing helps. Is there anyway to rewrite this query to go faster?

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  • How to define a query om a n-m table

    - by user559889
    Hi, I have some troubles defining a query. I have a Product and a Category table. A product can belong to multiple categories and vice versa so there is also a Product-Category table. Now I want to select all products that belong to a certain category. But if the user does not provide a category I want all products. I try to create a query using a join but this results in the product being selected multiple times if it belongs to multiple categories (in the case no specific category is queried). What kind of query do I have to create? Thanks

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  • Address component type in google maps geocoding

    - by user552828
    this is a part of my geocoding code. I want it to show only country of the selected place, but it shows all address components, My problem is I cant specify the address components object. There is a way of doing it that is written on documentation but I didnt understand, can you do it for me. if (geocoder) { geocoder.geocode({'latLng': latlng}, function(results, status) { if (status == google.maps.GeocoderStatus.OK) { var str = ""; $.each(results, function(){ str += "address components: <ul>" $.each(this.address_components, function(){ str +="<li>"+this.types.join(", ")+": "+this.long_name+"</li>"; }); str +="</ul>"; }); $("#geocode_info").html(str);

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  • Microsoft Reporting: Setting subreport parameters in code

    - by Svish
    How can I set a parameter of a sub-report? I have successfully hooked myself up to the SubreportProcessing event, I can find the correct sub-report through e.ReportPath, and I can add datasources through e.DataSources.Add. But I find no way of adding report parameters?? I have found people suggesting to add them to the master report, but I don't really want to do that, since the master report shouldn't have to be connected to the sub-report at all, other than that it is wrapping the sub-report. I am using one report as a master template, printing name of the report, page numbers etc. And the subreport is going to be the report itself. And if I could only find a way to set those report parameters of the sub-report I would be good to go... Clarification: Creating/Defining the parameters is not the problem. The problem is to set their values. I thought the natural thing to do was to do it in the SubreportProcessing event. And the SubreportProcessingEventArgs do in fact have a Parameters property. But it is read only! So how do you use that? How can I set their value?

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  • Deleting objects through foreign key relationship with T-SQL query

    - by LaserBeak
    Looking for a way to write the following LinQ to entities query as a T-SQL statement. repository.ProductShells.Where(x => x.ShellMembers.Any(sm => sm.ProductID == pid)).ToList().ForEach(x => repository.ProductShells.Remove(x)); The below is obviously not correct but I need it to delete respective ProductShell object where any ShellMember contains a ProductID equal to the passed in variable pid. I would presume this would involve a join statement to get the relevant ShellMembers. repository.Database.ExecuteSqlCommand("FROM Shellmembers WHERE ProductID={0} DELETE FK_ProductShell", pid); I have cascade delete enabled for the FK_ShellMembers_ProductShells foreign key, so when I delete the ProductShell it will delete all the ShellMembers that are associated with it. I am going to pass this statement to System.Data.Entity Database.ExecuteSqlCommand method.

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  • Benefits of migrating my work to a new web development framework?

    - by John
    When I first started programming with PHP, I was ignorant of other php frameworks (like code igniter, cake php, etc...). So I fell into the trap of re-inventing wheels, which had the benefit of being "fun" and "educational". Overtime, I discovered other open source products that I found useful, like smarty templating engine, jquery library, tcpdf library, fdf etc...so I started bundling these technologies along with things I've built over the years into a LAMP development framework to make life easier for myself. This pass year, I've been having fun developing on the code igniter framework. It does many of the things I do in my framework. Coding in CI feels natural because the MVC and ORM feels similar to the MVC and ORM of my framework. So now I'm contemplating migrating a lot of the plugins in my framework over to CI. The pros and cons I can think of for such a project are: Pros: benefit from the vast community of CI developers lots of other developers will be familiar with it better documentation Cons: I've built a lot of useful plugins against my own framework, and it will take a lot of time to move even just the essential ones at the moment, I still, work faster against my own framework than CI, just because I'm more familiar with it even if I did migrate to CI, there will always be newer and better frameworks in the near future, and i'll be contemplating this scenario again So my question is the following: perhaps I should leave my old framework as is, and for each new project I receive, I make a decision on whether the requirements are best served by developing with CI or my own framework. Is this the right approach?

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  • MySQL - display rows of names and addresses grouped by name, where name occures more than once

    - by Stoob
    I have two tables, "name" and "address". I would like to list the last_name and joined address.street_address of all last_name in table "name" that occur more than once in table "name". The two tables are joined on the column "name_id". The desired output would appear like so: 213 | smith | 123 bluebird | 14 | smith | 456 first ave | 718 | smith | 12 san antonia st. | 244 | jones | 78 third ave # 45 | 98 | jones | 18177 toronto place | Note that if the last_name "abernathy" appears only once in table "name", then "abernathy" should not be included in the result. This is what I came up with so far: SELECT name.name_id, name.last_name, address.street_address, count(*) FROM `name` JOIN `address` ON name.name_id = address.name_id GROUP BY `last_name` HAVING count(*) > 1 However, this produces only one row per last name. I'd like all the last names listed. I know I am missing something simple. Any help is appreciated, thanks!

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  • Why Eventmachine Defer slower than Ruby Thread?

    - by allenwei
    I have two scripts which using mechanize to fetch google index page. I assuming Eventmachine will faster than ruby thread, but not. Eventmachine code cost "0.24s user 0.08s system 2% cpu 12.682 total" Ruby Thread code cost "0.22s user 0.08s system 5% cpu 5.167 total " Am I use eventmachine in wrong way? Who can explain it to me, thanks! 1 Eventmachine require 'rubygems' require 'mechanize' require 'eventmachine' trap("INT") {EM.stop} EM.run do num = 0 operation = proc { agent = Mechanize.new sleep 1 agent.get("http://google.com").body.to_s.size } callback = proc { |result| sleep 1 puts result num+=1 EM.stop if num == 9 } 10.times do EventMachine.defer operation, callback end end 2 Ruby Thread require 'rubygems' require 'mechanize' threads = [] 10.times do threads << Thread.new do agent = Mechanize.new sleep 1 puts agent.get("http://google.com").body.to_s.size sleep 1 end end threads.each do |aThread| aThread.join end

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  • How to set document.domain for a dynamically generated IFRAME?

    - by Paras Chopra
    I am implementing CodeMirror (http://marijn.haverbeke.nl/codemirror/) on a page where document.domain needs to be declared (because of other IFRAMES on the page). CodeMirror generates a dynamic IFRAME to provide syntax highlighted code editing. The problem is that IE throws up 'Access Denied' (other browsers are fine) at the following piece of code mirror code: this.win = frame.contentWindow; ... var doc = this.win.document; <-- ERROR doc.open(); doc.write(html.join("")); doc.close(); It turns out IE doesn't inherit document.domain from parent IE. I can set document.domain in the IFRAME contents but IE throws up the error before I can even set the contents. Any ideas how to tackle this problem?

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  • TreeMap sort by value

    - by vito huang
    I'm new to java, i want to write an comparator to that will let me sort TreeMap by value instead of the default natural sorting. i tried something like this, but can't find out what went wrong: import java.util.*; class treeMap { public static void main(String[] args) { System.out.println("the main"); byValue cmp = new byValue(); Map<String, Integer> map = new TreeMap<String, Integer>(cmp); map.put("de",10); map.put("ab", 20); map.put("a",5); for (Map.Entry<String,Integer> pair: map.entrySet()) { System.out.println(pair.getKey()+":"+pair.getValue()); } } } class byValue implements Comparator<Map.Entry<String,Integer>> { public int compare(Map.Entry<String,Integer> e1, Map.Entry<String,Integer> e2) { if (e1.getValue() < e2.getValue()){ return 1; } else if (e1.getValue() == e2.getValue()) { return 0; } else { return -1; } } } I guess what am i asking is what controls what get pass to comparator function, can i get an Map.Entry pass to comparator?

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  • Sencha touch 2/ app workflow with navigation view

    - by eplatonov
    I am trying to understand how can I implement the same functionality which provides navigation view in sencha touch 2, but .... Each item of the 'Ext.NavigationView' component should have it's own unique set of 'navigationBar' elements. I mean set of buttons, for example. I know that I can do something like this: this.getMain().getNavigationBar().rightBox.removeAll(); this.getMain().getNavigationBar().rightBox.add(this.getSettingButton()); //where 'getSettingButton' predefined by me a button And do this action each time when 'push' event happens (clear 'navigationBar' and add appropriate set of buttons) Of course, I even can implement 'Ext.Panel' with 'layout: card' and set of 'Ext.panel' elements in the 'items' property, each of which will be have unique 'toolbar'. To control the behavior I can use 'setActiveItem' method. But, I think each of these approaches is a bit weird, isn't it? I expected that would be much more natural approach to implement it. Most likely I don't know what I need. Confirm my doubts. What is the best way to do it.

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  • Combine Hibernate class with @Bindable for SwingBuilder without Griffon?

    - by Misha Koshelev
    Dear All: I have implemented a back-end for my application in Groovy/Gradle, and am now trying to implement a GUI. I am using Hibernate for my data storage (with HSQLDB) per http://groovy.codehaus.org/Using+Hibernate+with+Groovy (with Jasypt for encryption) and it is working quite well. I was wondering if there are any good tips for using @Bindable with, e.g., an @Entity class such as @Entity class Book { @Id @GeneratedValue(strategy = GenerationType.AUTO) public Long id @OneToMany(cascade=CascadeType.ALL) public Set<Author> authors public String title String toString() { "$title by ${authors.name.join(', ')}" } } or if I am: (i) asking for Griffon (ii) completely on the wrong track? Thank you! Misha

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  • How would I UPDATE these table entries with SQL?

    - by CT
    I am working on an Asset Database problem. I enter assets into a database. Every object is an asset and has variables within the asset table. An object is also a type of asset. In this example the type is server. Here is the Query to retrieve all necessary data: SELECT asset.id ,asset.company ,asset.location ,asset.purchaseDate ,asset.purchaseOrder ,asset.value ,asset.type ,asset.notes ,server.manufacturer ,server.model ,server.serialNumber ,server.esc ,server.warranty ,server.user ,server.prevUser ,server.cpu ,server.memory ,server.hardDrive FROM asset LEFT JOIN server ON server.id = asset.id WHERE asset.id = '$id' How would I write a query to update an asset?

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  • SQL Server ORDER BY/WHERE with nested select

    - by Echilon
    I'm trying to get SQL Server to order by a column from a nested select. I know this isn't the best way of doing this but it needs to be done. I have two tables, Bookings and BookingItems. BookingItems contains StartDate and EndDate fields, and there can be multiple BookingItems on a Booking. I need to find the earliest startdate and latest end date from BookingItems, then filter and sort by these values. I've tried with a nested select, but when I try to use one of the selected columns in a WHERE or ORDER BY, I get an "Invalid Column Name". SELECT b.*, (SELECT COUNT(*) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS TotalRooms, (SELECT MIN(i.StartDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS StartDate, (SELECT MAX(i.EndDate) FROM bookingitems i WHERE b.BookingID = i.BookingID) AS EndDate FROM bookings b LEFT JOIN customers c ON b.CustomerID = c.CustomerID WHERE StartDate >= '2010-01-01' Am I missing something about SQL ordering? I'm using SQL Server 2008.

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  • LINQ DataLoadOptions - Retrieval of data via Fulltext/Broken Foreign Key Relationship

    - by Alex
    I've hit a brick wall: I have an SQL Function: FUNCTION [dbo].[ContactsFTS] (@searchtext nvarchar(4000)) RETURNS TABLE AS RETURN SELECT * FROM Contacts INNER JOIN CONTAINSTABLE(Contacts, *, @searchtext) AS KEY_TBL ON Contacts.Id = KEY_TBL.[KEY] which I am calling via LINQ public IQueryable<ContactsFTSResult> SearchByFullText(String searchText) { return db.ContactsFTS(searchText); } I am projecting the ContactsFTSResult collection into a List<Contact> which is then given to my viewmodel. Here is the problem: My Contacts table (and therefore the Contact object created via LINQ to SQL) has multiple FK relationships to other information, such as Contact.BillingAddressId is an FK to an Address.Id. That information is missing after I do the fulltext search (e.g. if I try to access Contact.BillingAddress it is null). Can I add this information somehow via DataLoadOptions? I tried LoadWith<Contact>(c => c.BillingAddress) but this doesn't work, I assume because of the fact that I'm calling the function instead of doing the whole query via LINQ.

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  • Practical rules for premature optimization

    - by DougW
    It seems that the phrase "Premature Optimization" is the buzz-word of the day. For some reason, iphone programmers in particular seem to think of avoiding premature optimization as a pro-active goal, rather than the natural result of simply avoiding distraction. The problem is, the term is beginning to be applied more and more to cases that are completely inappropriate. For example, I've seen a growing number of people say not to worry about the complexity of an algorithm, because that's premature optimization (eg http://stackoverflow.com/questions/2190275/help-sorting-an-nsarray-across-two-properties-with-nssortdescriptor/2191720#2191720). Frankly, I think this is just laziness, and appalling to disciplined computer science. But it has occurred to me that maybe considering the complexity and performance of algorithms is going the way of assembly loop unrolling, and other optimization techniques that are now considered unnecessary. What do you think? Are we at the point now where deciding between an O(n^n) and O(n!) complexity algorithm is irrelevant? What about O(n) vs O(n*n)? What do you consider "premature optimization"? What practical rules do you use to consciously or unconsciously avoid it? This is a bit vague, but I'm curious to hear other peoples' opinions on the topic.

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  • pass an ID with hyperlik but cant get this ID value from a fk in one table when i click in insert

    - by susan
    Something strange happened in my codes, actually I have a hyperlink that pass ID value in a query string to second page.in second page i have 2 sql datasource that both these sql datasources should get this id value and pass it to a filter parameter to show sth in datalist. so in another word I have a first page that has an hyperlink read ID value from a datasource and pass it to second page.its like below: <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%# "~/forumpage.aspx?ID="+Eval("ID")%>'><%#Eval("title")%> </asp:HyperLink> then in second page i have one sql datasource with a query like this ...where ID=@id and get this id in query string from db.it work great . but i have problem with second sql datasource in second page it has a query sth like below:...forms.question_id=@id then in sql reference both to query string as ID that get by first page in hyperlink. but when i click in insert button show me error with fk. error:Error:The INSERT statement conflicted with the FOREIGN KEY constraint "FK_forumreply_forumquestions". The conflict occurred in database "forum", table "dbo.forumquestions", column 'ID'. The statement has been terminated. my tables (question(ID,user_id(fk),Cat_id(fk),title,bodytext) (reply(ID,userr_id(fk),questionn_id(fk),titlereply,bodytestreply); When by hand in cb i gave a number in questionn_id like 1 it show me successful but when it want read from a filter by datasource this field face with problem. plzzzz help i really need skip from this part.and cause i am new i guess I cant understand the logic way clearly. <asp:SqlDataSource ID="sdsreply" runat="server" ConnectionString="<%$ ConnectionStrings:forumConnectionString %>" SelectCommand="SELECT forumreply.ID, forumreply.userr_id, forumreply.questionn_id, forumreply.bodytextreply, forumreply.datetimereply, forumquestions.ID AS Expr1, forumusers.ID AS Expr2, forumusers.username FROM forumquestions INNER JOIN forumreply ON forumquestions.ID = forumreply.questionn_id INNER JOIN forumusers ON forumquestions.user_id = forumusers.ID AND forumreply.userr_id = forumusers.ID where forumreply.questionn_id=@questionn_id"> <SelectParameters> <asp:QueryStringParameter Name="questionn_id" QueryStringField="ID" /> </SelectParameters> </asp:SqlDataSource> it is cb for second page in insert button: { if (Session["userid"] != null) { lblreply.Text = Session["userid"].ToString(); } else { Session["userid"]=null; } if (HttpContext.Current.User.Identity.IsAuthenticated) { lblshow.Text = string.Empty; string d = HttpContext.Current.User.Identity.Name; lblshow.Text =d + "???? ??? ?????." ; foreach (DataListItem item in DataList2.Items) { Label questionn_idLabel = (Label)item.FindControl("questionn_idLabel"); Label userr_idLabel = (Label)item.FindControl("userr_idLabel"); lbltest.Text = string.Empty; lbltest.Text = questionn_idLabel.Text; lblreply.Text = string.Empty; lblreply.Text = userr_idLabel.Text; } } else { lblshow.Text = "??? ??? ??? ??? ?? ?? ?????? ???? ???? ???? ????? ??? ??? ? ??? ????? ???????."; } } { if(HttpContext.Current.User.Identity.IsAuthenticated) { if (Page.IsValid) { SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["forumConnectionString"].ConnectionString); try { con.Open(); SqlCommand cmd = new SqlCommand("insert into forumreply (userr_id,questionn_id,bodytextreply,datetimereply)values(@userr_id,@questionn_id,@bodytextreply,@datetimereply)", con); cmd.Parameters.AddWithValue("userr_id",lblreply.Text); cmd.Parameters.AddWithValue("questionn_id",lbltest.Text); cmd.Parameters.AddWithValue("bodytextreply",txtbody.Text); cmd.Parameters.AddWithValue("datetimereply",DateTime.Now ); cmd.ExecuteNonQuery(); } catch (Exception exp) { Response.Write("<b>Error:</b>"); Response.Write(exp.Message); } finally { con.Close(); } lblmsg.Text = "???? ??? ?? ?????? ??? ?????.thx"; lblshow.Visible = false; //lbltxt.Text = txtbody.Text; txtbody.Text = string.Empty; } } else { lblmsg.Text = string.Empty; Session["rem"] = Request.UrlReferrer.AbsoluteUri; Response.Redirect("~/login.aspx"); } }

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  • MySQL FULLTEXT aggravation

    - by southof40
    Hi - I'm having problems with case-sensitivity in MySQL FULLTEXT searches. I've just followed the FULLTEXT example in the MySQL doco at http://dev.mysql.com/doc/refman/5.1/en/fulltext-boolean.html . I'll post it here for ease of reference ... CREATE TABLE articles ( id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY, title VARCHAR(200), body TEXT, FULLTEXT (title,body) ); INSERT INTO articles (title,body) VALUES ('MySQL Tutorial','DBMS stands for DataBase ...'), ('How To Use MySQL Well','After you went through a ...'), ('Optimizing MySQL','In this tutorial we will show ...'), ('1001 MySQL Tricks','1. Never run mysqld as root. 2. ...'), ('MySQL vs. YourSQL','In the following database comparison ...'), ('MySQL Security','When configured properly, MySQL ...'); SELECT * FROM articles WHERE MATCH (title,body) AGAINST ('database' IN NATURAL LANGUAGE MODE); ... my problem is that the example shows that SELECT returning the first and fifth rows ('..DataBase..' and '..database..') but I only get one row ('database') ! The example doesn't demonstrate what collation the table in the example had but I have ended up with latin1_general_cs on the title and body columns of my example table. My version of MySQL is 5.1.39-log and the connection collation is utf8_unicode_ci . I'd be really grateful is someone could suggest why my experience differs from the example in the manual ! Be grateful for any advice.

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  • Exit Tks mainloop in Python?

    - by Olof
    I'm writing a slideshow program with Tkinter, but I don't know how to go to the next image without binding a key. import os, sys import Tkinter import Image, ImageTk import time root = Tkinter.Tk() w, h = root.winfo_screenwidth(), root.winfo_screenheight() root.overrideredirect(1) root.geometry("%dx%d+0+0" % (w, h)) root.focus_set() root.bind("<Escape>", lambda e: e.widget.quit()) image_path = os.path.join(os.getcwd(), 'images/') dirlist = os.listdir(image_path) for f in dirlist: try: image = Image.open(image_path+f) tkpi = ImageTk.PhotoImage(image) label_image = Tkinter.Label(root, image=tkpi) # ? label_image.place(x=0,y=0,width=w,height=h) root.mainloop(0) except IOError: pass root.destroy() I would like to add a time.sleep(10) "instead" of the root.mainloop(0) so that it would go to the next image after 10s. Now it changes when I press ESC. How can I have a timer there?

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  • Getting error on inserting tuple values in postgreSQL table using python

    - by rahman.bd
    Hello, I want to keep last.fm's user recent music tracks list to postgresql database table using pylast interface.But when I tried to insert values to the table it shows errors.Code example: for i, artist in enumerate(recent_tracks): for key in sorted(artist): cur.execute(""" INSERT INTO u_recent_track(Playback_date,Time_stamp,Track) VALUES (%s,%s)""", (key, artist[key])) conn.commit() cur.execute("SELECT * FROM u_recent_track;") cur.fetchone() for row in cur: print ' '.join(row[1:]) cur.close() conn.close() Here "recent_tracks" tuple have the values for example: artist 0 - playback_date : 5 May 2010, 11:14 - timestamp : 1273058099 - track : Brian Eno - Web I want to store these value under u_recent_track(Tid,Playback_date,Time_stamp,Track).Can anybody have idea how to sort out this problem? when I tried to run, it shows error: Traceback (most recent call last): File "F:\JavaWorkspace\Test\src\recent_track_database.py", line 50, in <module> VALUES (%s,%s,%s)""", (key, artist[key])) IndexError: tuple index out of range Thanks in advanced!

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  • Why is insertion into my tree faster on sorted input than random input?

    - by Juliet
    Now I've always heard binary search trees are faster to build from randomly selected data than ordered data, simply because ordered data requires explicit rebalancing to keep the tree height at a minimum. Recently I implemented an immutable treap, a special kind of binary search tree which uses randomization to keep itself relatively balanced. In contrast to what I expected, I found I can consistently build a treap about 2x faster and generally better balanced from ordered data than unordered data -- and I have no idea why. Here's my treap implementation: http://pastebin.com/VAfSJRwZ And here's a test program: using System; using System.Collections.Generic; using System.Linq; using System.Diagnostics; namespace ConsoleApplication1 { class Program { static Random rnd = new Random(); const int ITERATION_COUNT = 20; static void Main(string[] args) { List<double> rndTimes = new List<double>(); List<double> orderedTimes = new List<double>(); rndTimes.Add(TimeIt(50, RandomInsert)); rndTimes.Add(TimeIt(100, RandomInsert)); rndTimes.Add(TimeIt(200, RandomInsert)); rndTimes.Add(TimeIt(400, RandomInsert)); rndTimes.Add(TimeIt(800, RandomInsert)); rndTimes.Add(TimeIt(1000, RandomInsert)); rndTimes.Add(TimeIt(2000, RandomInsert)); rndTimes.Add(TimeIt(4000, RandomInsert)); rndTimes.Add(TimeIt(8000, RandomInsert)); rndTimes.Add(TimeIt(16000, RandomInsert)); rndTimes.Add(TimeIt(32000, RandomInsert)); rndTimes.Add(TimeIt(64000, RandomInsert)); rndTimes.Add(TimeIt(128000, RandomInsert)); string rndTimesAsString = string.Join("\n", rndTimes.Select(x => x.ToString()).ToArray()); orderedTimes.Add(TimeIt(50, OrderedInsert)); orderedTimes.Add(TimeIt(100, OrderedInsert)); orderedTimes.Add(TimeIt(200, OrderedInsert)); orderedTimes.Add(TimeIt(400, OrderedInsert)); orderedTimes.Add(TimeIt(800, OrderedInsert)); orderedTimes.Add(TimeIt(1000, OrderedInsert)); orderedTimes.Add(TimeIt(2000, OrderedInsert)); orderedTimes.Add(TimeIt(4000, OrderedInsert)); orderedTimes.Add(TimeIt(8000, OrderedInsert)); orderedTimes.Add(TimeIt(16000, OrderedInsert)); orderedTimes.Add(TimeIt(32000, OrderedInsert)); orderedTimes.Add(TimeIt(64000, OrderedInsert)); orderedTimes.Add(TimeIt(128000, OrderedInsert)); string orderedTimesAsString = string.Join("\n", orderedTimes.Select(x => x.ToString()).ToArray()); Console.WriteLine("Done"); } static double TimeIt(int insertCount, Action<int> f) { Console.WriteLine("TimeIt({0}, {1})", insertCount, f.Method.Name); List<double> times = new List<double>(); for (int i = 0; i < ITERATION_COUNT; i++) { Stopwatch sw = Stopwatch.StartNew(); f(insertCount); sw.Stop(); times.Add(sw.Elapsed.TotalMilliseconds); } return times.Average(); } static void RandomInsert(int insertCount) { Treap<double> tree = new Treap<double>((x, y) => x.CompareTo(y)); for (int i = 0; i < insertCount; i++) { tree = tree.Insert(rnd.NextDouble()); } } static void OrderedInsert(int insertCount) { Treap<double> tree = new Treap<double>((x, y) => x.CompareTo(y)); for(int i = 0; i < insertCount; i++) { tree = tree.Insert(i + rnd.NextDouble()); } } } } And here's a chart comparing random and ordered insertion times in milliseconds: Insertions Random Ordered RandomTime / OrderedTime 50 1.031665 0.261585 3.94 100 0.544345 1.377155 0.4 200 1.268320 0.734570 1.73 400 2.765555 1.639150 1.69 800 6.089700 3.558350 1.71 1000 7.855150 4.704190 1.67 2000 17.852000 12.554065 1.42 4000 40.157340 22.474445 1.79 8000 88.375430 48.364265 1.83 16000 197.524000 109.082200 1.81 32000 459.277050 238.154405 1.93 64000 1055.508875 512.020310 2.06 128000 2481.694230 1107.980425 2.24 I don't see anything in the code which makes ordered input asymptotically faster than unordered input, so I'm at a loss to explain the difference. Why is it so much faster to build a treap from ordered input than random input?

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  • SharePoint filtered column that only allows item to be used once

    - by Jason
    I have a WSS 3.0 site that I use for change management. There are three primary lists on it -- a bug list, an enhancement list, and a release list. The release list has two lookup columns that provide a list of bugs and enhancements that are included in that particular release. I am trying to figure out how to filter the bug and enhancement list to include only items that have not already been included in another release. All the docs and examples I have seen regarding filtered lookups deal with a query on the list itself. For my situation, and if this was a SQL query, I would need to use a LEFT JOIN to generate the list.

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  • Dynamically determining table name given field name in SQL server

    - by Salman A
    Strange situation: I am trying to remove some hard coding from my code. There is a situation where I have a field, lets say "CityID", and using this information, I want to find out which table contains a primary key called CityID. Logically, you'd say that it's probably a table called "City" but it's not... that table is called "Cities". There are some other inconsistencies in database naming hence I can never be sure if removing the string "ID" and finding out the plural will be sufficient. Note: Once I figure out that CityID refers to a table called Cities, I will perform a join to replace CityID with city name on the fly. I will appreciate if someonw can also tell me how to find out the first varchar field in a table given its name.

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  • Ordering recursive result set in SQL Server

    - by Ben
    I am having extreme difficulty constructing a query which returns an XML style hierarchy. We have a database table which contains a hierarchy of URLs for our website. The table contains the columns: ID, URL, DisplayName, ParentID, ItemOrder The parent ID forms a recursive relationship between the current item and it's parent. The item should site below it's parent in the hierarchy and it should also be ordered using the item order against items at the same level in the hierarchy. I have managed to get a recursive query working so it drills down the hierarchy sequentially but I cannot order this by the item order as well. My current query is below: WITH Parents AS ( SELECT MenuItemId, URL, ParentItemId, ItemOrder FROM CambsMenu UNION ALL SELECT si.MenuItemId, si.URL, si.ParentItemId, si.ItemOrder FROM CambsMenu si INNER JOIN Parents p ON si.ParentItemId = p.MenuItemId ) SELECT DISTINCT * FROM Parents

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