Search Results

Search found 19090 results on 764 pages for 'greatest n per group'.

Page 183/764 | < Previous Page | 179 180 181 182 183 184 185 186 187 188 189 190  | Next Page >

• Database structure for ecommerce site

  - by imanc

  Hey Guys, I have been tasked with designing an ecommerce solution. The aspect that is causing me the most problems is the database. Currently the site consists of 10+ country based shops each with their own database (all residing on the same mysql instance). For the new site I'd rather all these shop databases be merged into one database so that all tables (products, orders, customers etc.) have a shop_id field. From a programming perspective this seems to make the most sense as we won't have to manage data across multiple databases. Currently the entire site generates about 120k orders a year, but is experiencing fairly heavy growth and we need to design a solution that will scale. In 5 years there may be more than a million orders per year and a database that contains 5 years order history (archiving maybe a solution here). The question is - do we use a single database, or do we keep the database-per-shop structure? I am currently trying to find supporting evidence for either avenue. The company I am designing the solution for prefer the per-shop database structure because they believe it will allow the sites to scale. But my argument is that the shop's database probably won't get that busy over the next few years that they exceed the capacity of a mysql database and a "no expenses spared" hardware set-up. I am wondering if anyone has any advice either way? Does anyone have experience with websites / ecommerce sites that have tables containing millions of records? I know there is probably not a clear answer here, but at what stage do we have too many records or too large table files to have a fast loading site? Also, if anyone has any advice on sources of information - books, websites, etc. where I can do further research, it would be highly appreciated! Cheers, imanc

  Read the article

• How is it possible to extend an SWFLoader with MXML?

  - by michael-cereda

  I'm currently doing the following.. Main application: " " In the Component: First Try: ]]> </fx:Script> <fx:Declarations></fx:Declarations> <mx:SWFLoader x="0" y="0" id="loader"/> </s:Group> Second Try: <?xml version="1.0" encoding="utf-8"?> <s:Group xmlns:fx="http://ns.adobe.com/mxml/2009" xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx"> <fx:Script> <![CDATA[ [Bindable] public var source:String; ]]> </fx:Script> <fx:Declarations> <!-- Place non-visual elements (e.g., services, value objects) here --> </fx:Declarations> <mx:SWFLoader x="0" y="0" source="{source}"/> </s:Group> But the component displays only a "Not Found" icon in both cases. Thanks

  Read the article

• Avoiding seasonality assumption for stl() or decompose() in R

  - by user303922

  Hello everybody, I have high frequency commodity price data that I need to analyze. My objective is to not assume any seasonal component and just identify a trend. Here is where I run into problems with R. There are two main functions that I know of to analyze this time series: decompose() and stl(). The problem is that they both take a ts object type with a frequency parameter greater than or equal to 2. Is there some way I can assume a frequency of 1 per unit time and still analyze this time series using R? I'm afraid that if I assume frequency greater than 1 per unit time, and seasonality is calculated using the frequency parameter, then my forecasts are going to depend on that assumption. names(crude.data)=c('Date','Time','Price') names(crude.data) freq = 2 win.graph() plot(crude.data$Time,crude.data$Price, type="l") crude.data$Price = ts(crude.data$Price,frequency=freq) I want frequency to be 1 per unit time but then decompose() and stl() don't work! dim(crude.data$Price) decom = decompose(crude.data$Price) win.graph() plot(decom$random[2:200],type="line") acf(decom$random[freq:length(decom$random-freq)]) Thank you.

  Read the article

• how to use two count or more on one selecting statament ..?

  - by jjj

  i develop this code: SELECT COUNT(NewEmployee.EmployeeID), NewEmployee.EmployeeId,EmployeeName FROM NewEmployee INNER JOIN NewTimeAttendance ON NewEmployee.EmployeeID = NewTimeAttendance.EmployeeID and NewTimeAttendance.TotalTime is null and (NewTimeAttendance.note = '' or NewTimeAttendance.note is null ) and (month=1 or month =2 or month = 3) GROUP BY NewEmployee.EmployeeID, EmployeeName order by EmployeeID from my previous two question selecting null stuff and counting issue...that amazing code is working beautifully fine..but now i need to select more than one count... ...searched (google) .... found alias...tried: SELECT COUNT(NewEmployee.EmployeeID) as attenddays, COUNT(NewEmployee.EmployeeID) as empabsent , NewEmployee.EmployeeId,EmployeeName FROM NewEmployee INNER JOIN NewTimeAttendance ON empabsent =NewEmployee.EmployeeID = NewTimeAttendance.EmployeeID and NewTimeAttendance.TotalTime is null and (NewTimeAttendance.note = '' or NewTimeAttendance.note is null ) and (month=1 or month =2 or month = 3) , attenddays = NewTimeAttendance.EmployeeID and NewTimeAttendance.TotalTime is null and (NewTimeAttendance.note = '' or NewTimeAttendance.note is null ) and (month=1 or month =2 or month = 3) GROUP BY NewEmployee.EmployeeID, EmployeeName order by EmployeeID Incorrect syntax near '='. second try: SELECT COUNT(NewEmployee.EmployeeID) as attenddays, COUNT(NewEmployee.EmployeeID) as absentdays, NewEmployee.EmployeeId,EmployeeName FROM NewEmployee INNER JOIN NewTimeAttendance ON attenddays(NewEmployee.EmployeeID = NewTimeAttendance.EmployeeID and NewTimeAttendance.TotalTime is null and (NewTimeAttendance.note = '' or NewTimeAttendance.note is null ) and (month=1 or month =2 or month = 3)) , absentdays(NewEmployee.EmployeeID = NewTimeAttendance.EmployeeID and NewTimeAttendance.TotalTime is null and (NewTimeAttendance.note = '' or NewTimeAttendance.note is null ) and (month=1 or month =2 or month = 3)) GROUP BY NewEmployee.EmployeeID, EmployeeName order by EmployeeID Incorrect syntax near '='. not very good ideas... so ...help thanks in advance

  Read the article

• Google Maps - custom icons with infoWindows

  - by hfidgen

  Hiya, As far as I can tell, this code is fine, and should display some custom icons with popup HTML windows. But the popups aren't working! Can anyone point out what I'm doing wrong? I can't seem to debug it myself. Thanks! function initialize() { if (GBrowserIsCompatible()) { var map = new GMap2(document.getElementById("map")); map.setCenter(new GLatLng(51.410416, -0.293884), 15); map.addControl(new GSmallMapControl()); map.addControl(new GMapTypeControl()); var i_parking = new GIcon(); i_parking.image = "http://google-maps-icons.googlecode.com/files/parking.png"; i_parking.iconSize = new GSize(32, 37); i_parking.iconAnchor = new GPoint(16, 37); icon_parking = { icon:i_parking }; var marker_office = new GMarker(new GLatLng(51.410416,-0.293884)); var marker_parking1 = new GMarker((new GLatLng(51.410178,-0.292000)),icon_parking); var marker_parking2 = new GMarker((new GLatLng(51.410152,-0.298948)),icon_parking); marker_parking1.openInfoWindowHtml('<strong>On Street Parking</strong><br>Church Road - 40p per hour'); marker_parking2.openInfoWindowHtml('<strong>Multi Storey - Fairfield</strong><br>Upper Car Park - 90p per half hour<br>Lower Car Park - £1.20 per hour'); map.addOverlay(marker_office); map.addOverlay(marker_parking1); map.addOverlay(marker_parking2); } }

  Read the article

• Calculating and saving space in Postgresql

  - by punkish

  I have a table in Pg like so CREATE TABLE t ( a BIGSERIAL NOT NULL, -- 8 b b SMALLINT, -- 2 b c SMALLINT, -- 2 b d REAL, -- 4 b e REAL, -- 4 b f REAL, -- 4 b g INTEGER, -- 4 b h REAL, -- 4 b i REAL, -- 4 b j SMALLINT, -- 2 b k INTEGER, -- 4 b l INTEGER, -- 4 b m REAL, -- 4 b CONSTRAINT a_pkey PRIMARY KEY (a) ) The above adds up to 50 bytes per row. My experience is that I need another 40% to 50% for system overhead, without even any user-created indexes to the above. So, about 75 bytes per row. I will have many, many rows in the table, potentially upward of 145 billion rows, so the table is going to be pushing 13-14 Terabytes. What tricks, if any, could I use to compact this table? My possible ideas below -- Convert the REAL values to INTEGERs. If they can stored as SMALLINT, that is a saving of 2 bytes per field. Convert the columns b .. m into an array. I don't need to search on those columns, but I do need to be able to return one column's value at a time. So, if I need column g, I could do something like SELECT a, arr[5] FROM t; Would I save space with the array option? Would there be a speed penalty? Any other ideas?

  Read the article

• R: Are there any alternatives to loops for subsetting from an optimization standpoint?

  - by Adam

  A recurring analysis paradigm I encounter in my research is the need to subset based on all different group id values, performing statistical analysis on each group in turn, and putting the results in an output matrix for further processing/summarizing. How I typically do this in R is something like the following: data.mat <- read.csv("...") groupids <- unique(data.mat$ID) #Assume there are then 100 unique groups results <- matrix(rep("NA",300),ncol=3,nrow=100) for(i in 1:100) { tempmat <- subset(data.mat,ID==groupids[i]) #Run various stats on tempmat (correlations, regressions, etc), checking to #make sure this specific group doesn't have NAs in the variables I'm using #and assign results to x, y, and z, for example. results[i,1] <- x results[i,2] <- y results[i,3] <- z } This ends up working for me, but depending on the size of the data and the number of groups I'm working with, this can take up to three days. Besides branching out into parallel processing, is there any "trick" for making something like this run faster? For instance, converting the loops into something else (something like an apply with a function containing the stats I want to run inside the loop), or eliminating the need to actually assign the subset of data to a variable?

  Read the article

• Linq2Sql: query - subquery optimisation

  - by Budda

  I have the following query: IList<InfrStadium> stadiums = (from sector in DbContext.sectors where sector.Type=typeValue select new InfrStadium(sector.TeamId) ).ToList(); and InfrStadium class constructor: private InfrStadium(int teamId) { IList<Sector> teamSectors = (from sector in DbContext.sectors where sector.TeamId==teamId select sector) .ToList<>(); ... work with data } Current implementation perform 1+n queries, where n - number of records fetched the 1st time. I want to optimize that. And another one I would love to do using 'group' operator in way like this: IList<InfrStadium> stadiums = (from sector in DbContext.sectors group sector by sector.TeamId into team_sectors select new InfrStadium(team_sectors.Key, team_sectors) ).ToList(); with appropriate constructor: private InfrStadium(int iTeamId, IEnumerable<InfrStadiumSector> eSectors) { IList<Sector> teamSectors = eSectors.ToList(); ... work with data } But attempt to launch query causes the following error: Expression of type 'System.Int32' cannot be used for constructor parameter of type 'System.Collections.Generic.IEnumerable`1[InfrStadiumSector]' Question 1: Could you please explain, what is wrong here, I don't understand why 'team_sectors' is applied as 'System.Int32'? I've tried to change query a little (replace IEnumerable with IQueryeable): IList<InfrStadium> stadiums = (from sector in DbContext.sectors group sector by sector.TeamId into team_sectors select new InfrStadium(team_sectors.Key, team_sectors.AsQueryable()) ).ToList(); with appropriate constructor: private InfrStadium(int iTeamId, IQueryeable<InfrStadiumSector> eSectors) { IList<Sector> teamSectors = eSectors.ToList(); ... work with data } In this case I've received another but similar error: Expression of type 'System.Int32' cannot be used for parameter of type 'System.Collections.Generic.IEnumerable1[InfrStadiumSector]' of method 'System.Linq.IQueryable1[InfrStadiumSector] AsQueryableInfrStadiumSector' Question 2: Actually, the same question: can't understand at all what is going on here... P.S. I have another to optimize query idea (describe here: Linq2Sql: query optimisation) but I would love to find a solution with 1 request to DB).

  Read the article

• MySQL to PostreSQL and Named Scope

  - by Lowgain

  I've got a named scope for one of my models that works fine. The code is: named_scope :inbox_threads, lambda { |user| { :include => [:deletion_flags, :recipiences], :conditions => ["recipiences.user_id = ? AND deletion_flags.user_id IS NULL", user.id], :group => "msg_threads.id" }} This works fine on my local copy of the app with a MySQL database, but when I push my app to Heroku (which only uses PostgreSQL), I get the following error: ActiveRecord::StatementInvalid (PGError: ERROR: column "msg_threads.subject" must appear in the GROUP BY clause or be used in an aggregate function: SELECT "msg_threads"."id" AS t0_r0, "msg_threads"."subject" AS t0_r1, "msg_threads"."originator_id" AS t0_r2, "msg_thr eads"."created_at" AS t0_r3, "msg_threads"."updated_at" AS t0_r4, "msg_threads"."url_key" AS t0_r5, "deletion_flags"."id" AS t1_r0, "deletion_flags"."user_id" AS t1_r1, "deletion_flags"."msg_thread_id" AS t1_r2, "deletion_flags"."confirmed" AS t1_r3, "deletion_flags"."created_at" AS t1_r4, "deletion_flags"."updated_at" AS t1_r5, "recipiences"."id" AS t2_r0, "recipiences"."user_id" AS t2_r1, "recipiences"."msg_thread_id" AS t2_r2, "recipiences"."created_at" AS t2_r3, "recipien ces"."updated_at" AS t2_r4 FROM "msg_threads" LEFT OUTER JOIN "deletion_flags" ON deletion_flags.msg_thread_id = msg_threads.id LEFT OUTER JOIN "recipiences" ON recipiences.msg_thread_id = msg_threads.id WHERE (recipiences.user_id = 1 AND deletion_flags.user_id IS NULL) GROUP BY msg_threads.id) I'm not as familiar with the working of Postgres, so what would I need to add here to get this working? Thanks!

  Read the article

• Entity Framework DateTime update extremely slow

  - by Phyxion

  I have this situation currently with Entity Framework: using (TestEntities dataContext = DataContext) { UserSession session = dataContext.UserSessions.FirstOrDefault(userSession => userSession.Id == SessionId); if (session != null) { session.LastAvailableDate = DateTime.Now; dataContext.SaveChanges(); } } This is all working perfect, except for the fact that it is terribly slow compared to what I expect (14 calls per second, tested with 100 iterations). When I update this record manually through this command: dataContext.Database.ExecuteSqlCommand(String.Format("update UserSession set LastAvailableDate = '{0}' where Id = '{1}'", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fffffff"), SessionId)); I get 55 calls per second, which is more than fast enough. However, when I don't update the session.LastAvailableDate but I update an integer (e.g. session.UserId) or string with Entity Framework, I get 50 calls per second, which is also more than fast enough. Only the datetime field is terrible slow. The difference of a factor 4 is unacceptable and I was wondering how I can improve this as I don't prefer using direct SQL when I can also use the Entity Framework. I'm using Entity Framework 4.3.1 (also tried 4.1).

  Read the article

• .NET 3.5 DataGridView Wont Save To Database

  - by Jimbo

  I have created a test Winforms application in Visual Studio 2008 (SP1) to see just how "RAD" C# and .NET 3.5 can be. So far I have mixed emotions. Added a service-based database to my application (MyDB.mdf) and added two tables - Contact (id [identity], name [varchar] and number [varchar] columns) and Group (id [identity] and name [varchar] columns) Added a DataSource, selected "Database" as the source, used the default connection string as the connection (which points to my database) and selected "All Tables" to be included in the data source and saved as MyDBDataSet Expanded the data source showing my two tables, selected the "Group" table and chose to display it as a DataGridView (from the dropdown option on the right of each entity) and dragged it onto Form1, thus creating a groupBindingNavigator, groupBindingSource, groupTableAdapter, tableAdapterManager, myDBDataset and groupDataGridView Press F5 to test the application, enter the name "Test" under the DataGridView's "name" column and click "Save" on the navigator which has autogenerated code to save the data that looks like this: private void groupBindingNavigatorSaveItem_Click(object sender, EventArgs e) { this.Validate(); this.groupBindingSource.EndEdit(); this.tableAdapterManager.UpdateAll(this.myDBDataSet); } Stop the application and have a look at the database data, you will see no data saved there in the "Group" table. I dont know why and cant find out how to fix it! Googled for about 30 minutes with no luck. The code is auto-generated with the controls, so you'd think that it would work too :)

  Read the article

• SQL problem - select accross multiple tables (user groups)

  - by morpheous

  I have a db schema which looks something like this: create table user (id int, name varchar(32)); create table group (id int, name varchar(32)); create table group_member (foobar_id int, user_id int, flag int); I want to write a query that allows me to so the following: Given a valid user id (UID), fetch the ids of all users that are in the same group as the specified user id (UID) AND have group_member.flag=3. Rather than just have the SQL. I want to learn how to think like a Db programmer. As a coder, SQL is my weakest link (since I am far more comfortable with imperative languages than declarative ones) - but I want to change that. Anyway here are the steps I have identified as necessary to break down the task. I would be grateful if some SQL guru can demonstrate the simple SQL statements - i.e. atomic SQL statements, one for each of the identified subtasks below, and then finally, how I can combine those statements to make the ONE statement that implements the required functionality. Here goes (assume specified user_id [UID] = 1): //Subtask #1. Fetch list of all groups of which I am a member Select group.id from user inner join group_member where user.id=group_member.user_id and user.id=1 //Subtask #2 Fetch a list of all members who are members of the groups I am a member of (i.e. groups in subtask #1) Not sure about this ... select user.id from user, group_member gm1, group_member gm2, ... [Stuck] //Subtask #3 Get list of users that satisfy criteria group_member.flag=3 Select user.id from user inner join group_member where user.id=group_member.user_id and user.id=1 and group_member.flag=3 Once I have the SQL for subtask2, I'd then like to see how the complete SQL statement is built from these subtasks (you dont have to use the SQL in the subtask, it just a way of explaining the steps involved - also, my SQL may be incorrect/inefficient, if so, please feel free to correct it, and point out what was wrong with it). Thanks

  Read the article

• Conditional row count in linq to nhibernate doesn't work

  - by Lucasus

  I want to translate following simple sql query into Linq to NHibernate: SELECT NewsId ,sum(n.UserHits) as 'HitsNumber' ,sum(CASE WHEN n.UserHits > 0 THEN 1 ELSE 0 END) as 'VisitorsNumber' FROM UserNews n GROUP BY n.NewsId My simplified UserNews class: public class AktualnosciUzytkownik { public virtual int UserNewsId { get; set; } public virtual int UserHits { get; set; } public virtual User User { get; set; } // UserId key in db table public virtual News News { get; set; } // NewsId key in db table } I've written following linq query: var hitsPerNews = (from n in Session.Query<UserNews>() group n by n.News.NewsId into g select new { NewsId = g.Key, HitsNumber = g.Sum(x => x.UserHits), VisitorsNumber = g.Count(x => x.UserHits > 0) }).ToList(); But generated sql just ignores my x => x.UserHits > 0 statement and makes unnecessary 'left outer join': SELECT news1_.NewsId AS col_0_0_, CAST(SUM(news0_.UserHits) AS INT) AS col_1_0_, CAST(COUNT(*) AS INT) AS col_2_0_ FROM UserNews news0_ LEFT OUTER JOIN News news1_ ON news0_.NewsId=news1_.NewsId GROUP BY news1_.NewsId How Can I fix or workaround this issue? Maybe this can be done better with QueryOver syntax?

  Read the article

• What are some arguments to support the position that the Dojo JavasScript library is secure, accessi

  - by LES2

  We have developed a small web application for a client. We decided on the Dojo framework to develop the app (requirements included were full i18n and a11y). Originally, the web app we developed was to be a "prototype", but we made the prototype production quality anyway, just in case. It turns out that the app we developed (or a variant of it) is going to production (many months hence), but it's so awesome that the enterprise architecture group is a little afraid. 508c compliant is a concern, as is security for this group. I now need to justify the use of Dojo to this architecture group, explicitly making the case that Dojo does not pose a security risk and that Dojo will not hurt accessibility (and that Dojo is there to help meet core requirements). Note: the web app currently requires JavaScript to be turned on and a stylesheet to work. We use a relatively minor subset of Dojo: of course, dojo core, and dijit.form.Form, ValidationTextBox and a few others. We do use dojox.grid.DataGrid (but no drag N drop or editable cells, which are not fully a11y). I have done some research of my own, of course, but I any information or advice you have would be most helpful. Regards, LES2

  Read the article

• Copy folder contents using VBScript

  - by LukeR

  I am trying to copy the contents of certain folders to another folder using VBScript. The goal is to enumerate a user's AD groups and then copy specific folder content based on those groups. I have code, which is currently not working. Dim Group,User,objFSO,objFolder,source,target,StrDomain StrDomain = "domain.local" FolderBase = "\\domain.local\netlogon\workgrps\icons" Set net = CreateObject("wscript.network") Struser = net.username target = "\\fs1\users\"&net.username&"\Desktop\AppIcons\" DispUserInWhichGroup() Function DispUserInWhichGroup() On Error Resume Next Set objFSO=CreateObject("Scripting.FileSystemObject") Set User = GetObject("WinNT://" & strDomain & "/" & strUser & ",user") For Each Group In User.Groups source = FolderBase & Group.name Set objFolder = GetFolder(source) For Each file in objFolder.Files objFSO.CopyFile source &"\"& file.name, target&"\"&file.name Next Next End Function This has been cobbled together from various sources, and I'm sure most of it is right, I just can't get it working completely. Any assistance would be great. Cheers.

  Read the article

• Dynamically loading external HTML in a div using Java Script

  - by user354051

  I have prepared some demo examples for the topic. There is page name "changelog.html" here: http://pantheon-studios.in/test/jquery/changelog.html This is working fine if loaded directly. I am trying to load this page dynamically into: http://pantheon-studios.in/test/jquery/index.html Here changelog.html doesn't behaving as expected. I think the init script on changelog.html is not getting executed or something else is happening when loading it dynamically. Like wise I do have couple of other pages using various jQuery and other java scripts plugins. Some of those needs initialization like animatedcollapse.js in the above example, and couple of them doesn't need initialization, you can directly call the script and go. I also gave a try using: jQuery.getScript("anim.js") after dynamically loading "changelog.html" but doesn't work. The "anim.js" contains animatedcollapse.addDiv('cat', 'fade=0,speed=400,group=pets,hide=1'); animatedcollapse.addDiv('dog', 'fade=0,speed=400,group=pets,hide=1'); animatedcollapse.addDiv('rabbit', 'fade=0,speed=400,group=pets,hide=1'); animatedcollapse.init(); I would really appreciate is some one point me out the right direction. I am completely new to web programming so please have some patience with me. Thanks

  Read the article

• Why is short project lifetime and other situation-specific reasons used to excuse crappy code? [clos

  - by sharptooth

  Every now and then (including on SO) people say things implying that "if the project is short lived you can leave obvious defects there" or "that memory leak only accounts for 100 bytes per whole program lifetime and could be left". Now in my practice I always reuse company-owned code to the greatest extent I can. Like if I need something and I can find it in the company codebase I take it from there and reuse or adapt. This means that any crappy code will be reused as well and I might notice or not notice defects therein. So the defect in some "test we only need for a month" can slip into a proram we ship to customers. And a leak that "only accounted for 100 bytes per lifetime" now could account for 100 bytes 10 times per second in a server application intended to run for months. That's why I don't understand why excuses like that are offered. Is our compamy the only one having a source control? Or are we the only company that requires writing human-readable code? Could anyone shed a light on why people seriously offer such excuses?

  Read the article

• MySQL - What is wrong with this query or my database? Terrible performance.

  - by Moss

  SELECT * from `employees` a LEFT JOIN (SELECT phone1 p1, count(*) c, FROM `employees` GROUP BY phone1) b ON a.phone1 = b.p1; I'm not sure if it is this query in particular that has the problem. I have been getting terrible performance in general with this database. The table in question has 120,000 rows. I have tried this particular query remotely and locally with the MyISAM and InnoDB engines, with different types of joins, and with and without an index on phone1. I can get this to complete in about 4 minutes on a 10,000 row table successfully but performance drops exponentially with larger tables. Remotely it will lose connection to the server and locally it brings my system to its knees and seems to go on forever. This query is only a smaller step I was trying to do when a larger query couldn't complete. Maybe I should explain the whole scenario. I have one big flat ugly table that lists a bunch of people and their contact info and the info of the companies they work for. I'm trying to normalize the database and intelligently determine which phone numbers apply to individual people and which apply to an office location. My reasoning is that if a phone number occurs multiple times and the number of occurrence equals the number of times that the street address it is attached to occurs then it must be an office number. So the first step is to count each phone number grouping by phone number. Normally if you just use COUNT()...GROUP BY it will only list the first record it finds in that group so I figured I have to join the full table to the count table where the phone number matches. This does work but as I said I can't successfully complete it on any table much larger than 10,000 rows. This seems pathetic and this doesn't seem like a crazy query to do. Is there a better way to achieve what I want or do I have to break my large table into 12 pieces or is there something wrong with the table or db?

  Read the article

• RegEx: difference between "(?:...) and normal parentheses

  - by N0thing

  >>> re.findall(r"(?:do|re|mi)+", "mimi") ['mimi'] >>> re.findall(r"(do|re|mi)+", "mimi") ['mi'] According to my understanding of the definitions, it should produce the same answer. The only difference between (...) and (?:...) should be whether or not we can use back-references later. Am I missing something? (...) Matches whatever regular expression is inside the parentheses, and indicates the start and end of a group; the contents of a group can be retrieved after a match has been performed, and can be matched later in the string with the \number special sequence, described below. To match the literals '(' or ')', use ( or ), or enclose them inside a character class: [(] [)]. (?:...) A non-capturing version of regular parentheses. Matches whatever regular expression is inside the parentheses, but the substring matched by the group cannot be retrieved after performing a match or referenced later in the pattern.

  Read the article

• Search and Matching algorithm

  - by Tony

  Hello everyone. I am trying to come up with an algorithm to do the following: I have total 12 cells that I need to fill until program stops. I have 3 rows and each row has 4 columns. As an example, let me illustrate this as in airplane. So you have 3 rows and each row has 4 columns and you have window/aisle seats. Each row will have a window seat, aisle seat, aisle seat and window seat (|WA AW| Just like seat arrangement in airplane). At each iteration (different set of passengers), there would be some number of passengers (between 1 and 12) and I need to seat them closest together possible (Seat together). And I do this for next group (each iteration) until program stops (It will stop when I am done with every group). For example, I have 3 passengers (A,B,and C) and A wants to seat in Window, B wants to seat in Aisle and C wants to seat in Window. Assuming that all the seats (all 12) are available, I could place them like |A# BC| or |CB #A| and mark the seats dirty (so I don’t pick same seats again for next passengers). And I do this for next group (iteration). I am not sure if this right forum, but if somebody can advise me how I should accomplish, I would really appreciate it. Thanks.

  Read the article

• MySQL: SELECT highest column value when WHERE finds similar entries

  - by Ike

  My question is comparable to this one, but not quite the same. I have a database with a huge amount of books, with different editions of some of the same book titles. I'm looking for an SQL statement giving me the highest edition number of each of the titles I'm selecting with a WHERE clause (to find specific book series). Here's what the table looks like: |id|title |edition|year| |--|-------------------------|-------|----| |01|Serie One Title One |1 |2007| |02|Serie One Title One |2 |2008| |03|Serie One Title One |3 |2009| |04|Serie One Title Two |1 |2001| |05|Serie One Title Three |1 |2008| |06|Serie One Title Three |2 |2009| |07|Serie One Title Three |3 |2010| |08|Serie One Title Three |4 |2011| |--|-------------------------|-------|----| The result I'm looking for is this: |id|title |edition|year| |--|-------------------------|-------|----| |03|Serie One Title One |3 |2009| |04|Serie One Title Two |1 |2001| |08|Serie One Title Three |4 |2011| |--|-------------------------|-------|----| The closest I got was using this statement: select id, title, max(edition), max(year) from books where title like "serie one%" group by name; but it returns the highest edition and year and includes the first id it finds: |--|-----------------------|-------|----| |01|Serie One Title One |3 |2009| |04|Serie One Title Two |1 |2001| |05|Serie One Title Three |4 |2011| |--|-----------------------|-------|----| This fancy join also comes close, but doesn't give the right result: select b.id, b.title, b.edition, b.year from books b inner join (select name, max(edition) as maxedition from books group by title) g on b.edition = g.maxedition where b.title like "serie one%" group by title; Using this I'm getting unique titles, but mostly old editions.

  Read the article

• Computation overhead in C# - Using getters/setters vs. modifying arrays directly and casting speeds

  - by Jeffrey Kern

  I was going to write a long-winded post, but I'll boil it down here: I'm trying to emulate the graphical old-school style of the NES via XNA. However, my FPS is SLOW, trying to modify 65K pixels per frame. If I just loop through all 65K pixels and set them to some arbitrary color, I get 64FPS. The code I made to look-up what colors should be placed where, I get 1FPS. I think it is because of my object-orented code. Right now, I have things divided into about six classes, with getters/setters. I'm guessing that I'm at least calling 360K getters per frame, which I think is a lot of overhead. Each class contains either/and-or 1D or 2D arrays containing custom enumerations, int, Color, or Vector2D, bytes. What if I combined all of the classes into just one, and accessed the contents of each array directly? The code would look a mess, and ditch the concepts of object-oriented coding, but the speed might be much faster. I'm also not concerned about access violations, as any attempts to get/set the data in the arrays will done in blocks. E.g., all writing to arrays will take place before any data is accessed from them. As for casting, I stated that I'm using custom enumerations, int, Color, and Vector2D, bytes. Which data types are fastest to use and access in the .net Framework, XNA, XBox, C#? I think that constant casting might be a cause of slowdown here. Also, instead of using math to figure out which indexes data should be placed in, I've used precomputed lookup tables so I don't have to use constant multiplication, addition, subtraction, division per frame. :)

  Read the article

• Mysql count and sum from two diferent tables

  - by Agent_x

  Hi all, i have a problem with some querys in php and mysql: I have 2 diferent tables with one field in common: table 1 id | hits | num_g | cats | usr_id |active 1 | 10 | 11 | 1 | 53 | 1 2 | 13 | 16 | 3 | 53 | 1 1 | 10 | 22 | 1 | 22 | 1 1 | 10 | 21 | 3 | 22 | 1 1 | 2 | 6 | 2 | 11 | 1 1 | 11 | 1 | 1 | 11 | 1 table 2 id | usr_id | points 1 | 53 | 300 Now i use this statement to sum just the total from the table 1 every id count + 1 too SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) AS tot_h FROM table1 WHERE usr_id!='0' GROUP BY usr_id ASC LIMIT 0 , 15 and i get the total for each usr_id usr_id| tot_h | 53 | 50 22 | 63 11 | 20 until here all is ok, now i have a second table with extra points (table2) I try this: SELECT usr_id, COUNT( id ) + SUM( num_g + hits ) + (SELECT points FROM table2 WHERE usr_id != '0' ) AS tot_h FROM table1 WHERE usr_id != '0' GROUP BY usr_id ASC LIMIT 0 , 15 but it seems to sum the 300 extra points to all users: usr_id| tot_h | 53 | 350 22 | 363 11 | 320 Now how i can get the total like the first try but + the secon table in one statement? because now i have just one entry in the second table but i can be more there. thanks for all the help. =============================================================================== hi thomas thanks for your reply, i think is in the right direction, but im getting weirds results, like usr_id | tot_h 22 | NULL <== i think the null its because that usr_id as no value in the table2 53 | 1033 Its like the second user is getting all the the values. then i try this one: SELECT table1.usr_id, COUNT( table1.id ) + SUM( table1.num_g + table1.hits + table2.points ) AS tot_h FROM table1 LEFT JOIN table2 ON table2.usr_id = table1.usr_id WHERE table1.usr_id != '0' AND table2.usr_id = table1.usr_id GROUP BY table1.usr_id ASC Same result i just get the sum of all values and not by each user, i need something like this result: usr_id | tot_h 53 | 53 <==== plus 300 points on table1 22 | 56 <==== plus 100 points on table2 /////////the result i need //////////// usr_id | tot_h 53 | 353 <==== plus 300 points on table2 22 | 156 <==== plus 100 points on table2 I think the structure need to be something like this Pseudo statements ;) from table1 count all id to get the number of record where the usr_id are then sum hits + num_g and from table2 select the extra points where the usr_id are the same as table1 and get teh result: usr_id | tot_h 53 | 353 22 | 156

  Read the article

• How to delete ProgIDs from other user accounts when uninstalling from Windows?

  - by Mordachai

  I've been investigating "how should a modern windows c++ application register its file types" with Windows (see http://stackoverflow.com/questions/2828637/c-how-do-i-correctly-register-and-unregister-file-type-associations-for-our-ap). And having combed through the various MSDN articles on the subject, the summary appears to be as follows: The installer (elevated) should register the global ProgID HKLM\Software\Classes\my-app.my-doc[.version] (e.g. HKLM\Software\Classes\TextPad.text) The installer also configures default associations for its document types (e.g. .myext) and points this to the aforementioned global ProgID in HKLM. NOTE: a user interface should be provided here to allow the user to either accept all default associations, or to customize which associations should be set. The application, running standard (unelevated), should provide a UI for allowing the current user to set their personal associations as is available in the installer, except that these associations are stored in HKCU\Software\Classes (per user, not per machine). The UN-installer is then responsible for deleting all registered ProgIDs (but should leave the actual file associations alone, as Windows is smart enough to handle associations pointing to missing ProgIDs, and this is the specified desired behavior by MSDN). So that schema sounds reasonable to me, except when I consider #4: How does an uninstaller, running elevated for a given user account, delete any per-user ProgIDs created in step #3 for other users? As I understand things, even in elevated mode, an uninstaller cannot go into another user's registry hive and delete items? Or can it? Does it have to load each given user hive first? What are the rules here? Thanks for any insight you might have to offer! EDIT: See below for the solution (My question was founded in confusion)

  Read the article

• How can I build value for "for-each" expression in XSLT with help of parameter

  - by Artic

  I need to navigate through this xml tree. <publication> <corporate> <contentItem> <metadata>meta</metadata> <content>html</content> </contentItem> <contentItem > <metadata>meta1</metadata> <content>html1</content> </contentItem> </corporate> <eurasia-and-africa> ... </eurasia-and-africa> <europe> ... </europe> </publication> and convert it to html with this stylesheet <ul> <xsl:variable name="itemsNode" select="concat('publicationManifest/',$group,'/contentItem')"></xsl:variable> <xsl:for-each select="$itemsNode"> <li> <xsl:value-of select="content"/> </li> </xsl:for-each> </ul> $group is a parameter with name of group for example "corporate". I have an error with compilation of this stylsheet. SystemID: D:\1\contentsTransform.xslt Engine name: Saxon6.5.5 Severity: error Description: The value is not a node-set Start location: 18:0 What the matter?

  Read the article

< Previous Page | 179 180 181 182 183 184 185 186 187 188 189 190  | Next Page >