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  • Core Data object into an NSDictionary with possible nil objects

    - by Chuck
    I have a core data object that has a bunch of optional values. I'm pushing a table view controller and passing it a reference to the object so I can display its contents in a table view. Because I want the table view displayed a specific way, I am storing the values from the core data object into an array of dictionaries then using the array to populate the table view. This works great, and I got editing and saving working properly. (i'm not using a fetched results controller because I don't have anything to sort on) The issue with my current code is that if one of the items in the object is missing, then I end up trying to put nil into the dictionary, which won't work. I'm looking for a clean way to handle this, I could do the following, but I can't help but feeling like there's a better way. *passedEntry is the core data object handed to the view controller when it is pushed, lets say it contains firstName, lastName, and age, all optional. if ([passedEntry firstName] != nil) { [dictionary setObject:[passedEntry firstName] forKey:@"firstName"] } else { [dictionary setObject:@"" forKey:@"firstName"] } And so on. This works, but it feels kludgy, especially if I end up adding more items to the core data object down the road.

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  • return Queryable<T> or List<T> in a Repository<T>

    - by Danny Chen
    Currently I'm building an windows application using sqlite. In the data base there is a table say User, and in my code there is a Repository<User> and a UserManager. I think it's a very common design. In the repository there is a List method: //Repository<User> class public List<User> List(where, orderby, topN parameters and etc) { //query and return } This brings a problem, if I want to do something complex in UserManager.cs: //UserManager.cs public List<User> ListUsersWithBankAccounts() { var userRep = new UserRepository(); var bankRep = new BankAccountRepository(); var result = //do something complex, say "I want the users live in NY //and have at least two bank accounts in the system } You can see, returning List<User> brings performance issue, becuase the query is executed earlier than expected. Now I need to change it to something like a IQueryable<T>: //Repository<User> class public TableQuery<User> List(where, orderby, topN parameters and etc) { //query and return } TableQuery<T> is part of the sqlite driver, which is almost equals to IQueryable<T> in EF, which provides a query and won't execute it immediately. But now the problem is: in UserManager.cs, it doesn't know what is a TableQuery<T>, I need to add new reference and import namespaces like using SQLite.Query in the business layer project. It really brings bad code feeling. Why should my business layer know the details of the database? why should the business layer know what's SQLite? What's the correct design then?

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  • Python + Expat: Error on &#0; entities

    - by clacke
    I have written a small function, which uses ElementTree and xpath to extract the text contents of certain elements in an xml file: #!/usr/bin/env python2.5 import doctest from xml.etree import ElementTree from StringIO import StringIO def parse_xml_etree(sin, xpath): """ Takes as input a stream containing XML and an XPath expression. Applies the XPath expression to the XML and returns a generator yielding the text contents of each element returned. >>> parse_xml_etree( ... StringIO('<test><elem1>one</elem1><elem2>two</elem2></test>'), ... '//elem1').next() 'one' >>> parse_xml_etree( ... StringIO('<test><elem1>one</elem1><elem2>two</elem2></test>'), ... '//elem2').next() 'two' >>> parse_xml_etree( ... StringIO('<test><null>&#0;</null><elem3>three</elem3></test>'), ... '//elem2').next() 'three' """ tree = ElementTree.parse(sin) for element in tree.findall(xpath): yield element.text if __name__ == '__main__': doctest.testmod(verbose=True) The third test fails with the following exception: ExpatError: reference to invalid character number: line 1, column 13 Is the � entity illegal XML? Regardless whether it is or not, the files I want to parse contain it, and I need some way to parse them. Any suggestions for another parser than Expat, or settings for Expat, that would allow me to do that?

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  • Looping over commits for a file with jGit

    - by Andy Jarrett
    I've managed to get to grips with the basics of jGit file in terms of connecting to a repos and adding, commiting, and even looping of the commit messages for the files. File gitDir = new File("/Users/myname/Sites/helloworld/.git"); RepositoryBuilder builder = new RepositoryBuilder(); Repository repository; repository = builder.setGitDir(gitDir).readEnvironment() .findGitDir().build(); Git git = new Git(repository); RevWalk walk = new RevWalk(repository); RevCommit commit = null; // Add all files // AddCommand add = git.add(); // add.addFilepattern(".").call(); // Commit them // CommitCommand commit = git.commit(); // commit.setMessage("Commiting from java").call(); Iterable<RevCommit> logs = git.log().call(); Iterator<RevCommit> i = logs.iterator(); while (i.hasNext()) { commit = walk.parseCommit( i.next() ); System.out.println( commit.getFullMessage() ); } What I want to do next is be able to get all the commit message for a single file and then be able revert the single file back to a specific reference/point in time.

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  • MVC3 View For Loop values initialization

    - by Ryan
    So I have a for loop in my View that is supposed to render out the input boxes. Now inside these input boxes I want to put lables that disappear when you click on them. This is all simple. Now it's probably because my brain was wired for php first, and it has been difficult to get it to think in lambdas and object orientation, but I can't figure out how to do this: @{ for (int i = 0; i < 3; i++) { <div class="editor-label grid_2">User</div> Model.Users[i].UserFirstName = "First Name"; Model.Users[i].UserLastName = "Last Name"; Model.Users[i].UserEmailAddress = "Email Address"; <div class="grid_10"> @Html.TextBoxFor(m => Model.Users[i].UserFirstName, new { @class = "user-input" }) @Html.TextBoxFor(m => Model.Users[i].UserLastName, new { @class = "user-input" }) @Html.TextBoxFor(m => Model.Users[i].UserEmailAddress, new { @class = "user-input-long" }) @Html.CheckBoxFor(m => Model.Users[i].IsUserAdmin) <span>&nbsp;admin?</span> </div> <div class="clear"> </div> } } And initialize the values for the users. And you're probably thinking "Of course that won't work. You're going to get a Null Reference Exception", and you would be correct. I might need to initialize them somewhere else and I don't realize it but I'm just not sure. I've tried the [DefaultValue("First Name")] route and that doesn't work. I'm probably thinking about this wrong, but my brain is already shot from trying to figure out how to wire up these events to the controller, so any help would be appreciated!

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  • In a Windows forms application, how can I setup can I set up the SelectedIndexChanged handle for 4 d

    - by Alex
    In a Windows forms application, within a DataGridView, I have 4 different DataGridCombobox controlshow can I set up the handler SelectedIndexChanged handler for the first combobox via the EditingControlShowing event. I added code for a second combobox but the SelectedIndexChanged didn't get wired up. Here's my code. Any advice would be appreciated. private ComboBox countryCombo; private EventHandler countryHandler; private ComboBox partCombo; private EventHandler partHandler; private void dataGridView2_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e) { countryCombo = e.Control as ComboBox; if (countryCombo != null) { //remove any existing handler if there is one countryCombo.SelectedIndexChanged -= countryHandler; //add the new handler countryCombo.SelectedIndexChanged += new EventHandler(countryCombo_SelectedIndexChanged); } if (partCombo != null) { partCombo.SelectedIndexChanged -= partHandler; partCombo.SelectedIndexChanged += new EventHandler(partCombo_SelectedIndexChanged); } } private void countryCombo_SelectedIndexChanged(object sender, EventArgs e) { ComboBox box = (ComboBox) sender; //MessageBox.Show(box.Items.Count.ToString()); int rowNum = dataGridView2.CurrentCell.RowIndex; dataGridView2.BeginEdit(false); dataGridView2.Rows[0].Cells[2].Value = "abcdef"; dataGridView2.EndEdit(); } private void dataGridView2_CellContentClick(object sender, DataGridViewCellEventArgs e) { int cellColumn = e.ColumnIndex; //MessageBox.Show("Column is: " + cellColumn.ToString()); } private void partCombo_SelectedIndexChanged(object sender, EventArgs e) { ComboBox box = (ComboBox)sender; string partNumber = box.SelectedValue as string; // ToDo: now we need to get the HTSUS from the database so we can //populate the field int rowNum = dataGridView2.CurrentCell.RowIndex; dataGridView2.BeginEdit(false); dataGridView2.Rows[0].Cells[2].Value = "abcdef"; dataGridView2.EndEdit(); } } Al D.

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  • Select return dynamic columns

    - by Ascalonian
    I have two tables: Standards and Service Offerings. A Standard can have multiple Service Offerings. Each Standard can have a different number of Service Offerings associated to it. What I need to be able to do is write a view that will return some common data and then list the service offerings on one line. For example: Standard Id | Description | SO #1 | SO #2 | SO #3 | ... | SO #21 | SO Count 1 | One | A | B | C | ... | G | 21 2 | Two | A | | | ... | | 1 3 | Three | B | D | E | ... | | 3 I have no idea how to write this. The number of SO columns is set to a specific number (21 in this case), so we cannot exceed past that. Any ideas on how to approach this? A place I started is below. It just returned multiple rows for each Service Offering, when they need to be on one row. SELECT * FROM SERVICE_OFFERINGS WHERE STANDARD_KEY IN (SELECT STANDARD_KEY FROM STANDARDS)

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  • Linq, should I join those two queries together?

    - by 5YrsLaterDBA
    I have a Logins table which records when user is login, logout or loginFailed and its timestamp. Now I want to get the list of loginFailed after last login and the loginFailed happened within 24 hrs. What I am doing now is get the last login timestamp first. then use second query to get the final list. do you think I should join those two queris together? why not? why yes? var lastLoginTime = (from inRecord in db.Logins where inRecord.Users.UserId == userId && inRecord.Action == "I" orderby inRecord.Timestamp descending select inRecord.Timestamp).Take(1); if (lastLoginTime.Count() == 1) { DateTime lastInTime = (DateTime)lastLoginTime.First(); DateTime since = DateTime.Now.AddHours(-24); String actionStr = "F"; var records = from record in db.Logins where record.Users.UserId == userId && record.Timestamp >= since && record.Action == actionStr && record.Timestamp > lastInTime orderby record.Timestamp select record; }

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  • Incrementing value by one over a lot of rows

    - by Andy Gee
    Edit: I think the answer to my question lies in the ability to set user defined variables in MySQL through PHP - the answer by Multifarious has pointed me in this direction Currently I have a script to cycle over 10M records, it's very slow and it goes like this: I first get a block of 1000 results in an array similar to this: $matches[] = array('quality_rank'=>46732, 'db_id'=>5532); $matches[] = array('quality_rank'=>12324, 'db_id'=>1234); $matches[] = array('quality_rank'=>45235, 'db_id'=>8345); $matches[] = array('quality_rank'=>75543, 'db_id'=>2562); I then cycle through them one by one and update the record $mult = count($matches)*2; foreach($matches as $m) { $rank++; $score = (($m[quality_rank] + $rank)/($mult))*100; $s = "UPDATE `packages_sorted` SET `price_rank` = '".$rank."', `deal_score` = '".$score."' WHERE `db_id` = '".$m[db_id]."' LIMIT 1"; } It seems like this is a very slow way of doing it but I can't find another way to increment the field price_rank by one each time. Can anyone suggest a better method. Note: Although I wouldn't usually store this kind of value in a database I really do need on this occasion for comparison search queries later on in the project. Any help would be kindly appreciated :)

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  • MySQL query against pseudo-key-value pair data in WordPress custom query

    - by andrevr
    I'm writing a custom WordPress query to use some of the data which the Woothemes Diarise theme creates. Diarise is an event planner theme with calendar blah, blah... and uses custom fields to store the event start and end dates in WP custom fields in the *wp_postmeta* table, which implements a key-value store. So for each post in the "event" category, there are 2 records in *wp_postmeta*, named *event_start_date* and *event_end_date* that I'm interested in. The task is to compare a tourist's arrival and departure dates with the start and end dates of events, yielding a what's on list of events available. We thought we'd killed it with a grand flash of logic, that goes like this: Disregard any event that ends before the tourist arrives, and any that begin after the departure date. I wrote this query: SELECT wposts.* FROM wp_posts wposts LEFT JOIN wp_postmeta wpostmeta ON wposts.ID = wpostmeta.post_id LEFT JOIN wp_term_relationships ON (wposts.ID = wp_term_relationships.object_id) LEFT JOIN wp_term_taxonomy ON (wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id) WHERE wp_term_taxonomy.taxonomy = 'category' AND wp_term_taxonomy.term_id IN(3,4) AND ( wpostmeta.meta_key = 'event_start_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) > '2010-07-31' ) ) AND ( wpostmeta.meta_key = 'event_end_date' AND NOT ( concat(subst(wpostmeta.meta_value,7,4),'-',subst(wpostmeta.meta_value,4,2),'-',subst(wpostmeta.meta_value,1,2) < '2010-05-01' ) ) ) ORDER BY wpostmeta.meta_value ASC And, of course it returns no records. The problem I believe is in the dual reference to wpostmeta.meta_key, but how to get around that?

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  • identifier ... is undefined when trying to run pure C code in Cuda using nvcc

    - by Lostsoul
    I'm new and learning Cuda. A approach that I'm trying to use to learn is to write code in C and once I know its working start converting it to Cuda since I read that nvcc compiles Cuda code but complies everything else using plain old c. My code works in c(using gcc) but when I try to compile it using nvcc(after changing the file name from main.c to main.cu) I get main.cu(155): error: identifier "num_of_rows" is undefined main.cu(155): error: identifier "num_items_in_row" is undefined 2 errors detected in the compilation of "/tmp/tmpxft_00002898_00000000-4_main.cpp1.ii". Basically in my main method I send data to a function like this: process_list(count, countListItem, list); the first two items are ints and the last item(list) is a matrix. Then I create my function like this: void process_list(int num_of_rows, int num_items_in_row, int current_list[num_of_rows][num_items_in_row]) { This line is where I get my errors when using nvcc(line 155). I need to convert this code to cuda anyway so no need to troubleshoot this specific issue(plus code is quite large) but I'm wondering if I'm wrong about nvcc treating the C part of your code like plain C. In the book cuda by example I just used nvcc to compile but do I need any extra flags when just using pure c?

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  • TypeError when using v 0.8.1 of FLOT library, but no error with v. 0.7

    - by DanielAttard
    I need some help to figure out why I am getting an error when trying to create a simple graph using the jQuery FLOT library. When I reference version 0.7 of the FLOT library, the page renders correctly: http://attardpropertytax.ca/flot07.html But when I switch to version 0.8.1 of the FLOT library, the page returns an error saying: Uncaught TypeError: Cannot read property 'left' of null http://attardpropertytax.ca/flot81.html The HTML is the same for both pages, so I cannot figure out why the new version 0.8.1 of FLOT returns an error, but the old version 0.7 does not. Any ideas? I somehow stumbled across a work-around that managed to fix my problem. I'm nut sure why, but I had to comment-out the following two sections of code from the v. 0.8.1 FLOT library: This was the first spot: // If the grid is visible, add its border width to the offset for (var a in plotOffset) { if(typeof(options.grid.borderWidth) == "object") { plotOffset[a] += showGrid ? options.grid.borderWidth[a] : 0; } else { plotOffset[a] += showGrid ? options.grid.borderWidth : 0; } } And this was the second spot: if (isNaN(v) || v < axis.min || v > axis.max // skip those lying on the axes if we got a border || (t == "full" && ((typeof bw == "object" && bw[axis.position] > 0) || bw > 0) && (v == axis.min || v == axis.max))) continue; I'm sure eventually @DNS will be taking a look at this question and maybe he will be able to help me understand what is going wrong with my code. Thanks.

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  • How can I merge two Linq IEnumerable<T> queries without running them?

    - by makerofthings7
    How do I merge a List<T> of TPL-based tasks for later execution? public async IEnumerable<Task<string>> CreateTasks(){ /* stuff*/ } My assumption is .Concat() but that doesn't seem to work: void MainTestApp() // Full sample available upon request. { List<string> nothingList = new List<string>(); nothingList.Add("whatever"); cts = new CancellationTokenSource(); delayedExecution = from str in nothingList select AccessTheWebAsync("", cts.Token); delayedExecution2 = from str in nothingList select AccessTheWebAsync("1", cts.Token); delayedExecution = delayedExecution.Concat(delayedExecution2); } /// SNIP async Task AccessTheWebAsync(string nothing, CancellationToken ct) { // return a Task } I want to make sure that this won't spawn any task or evaluate anything. In fact, I suppose I'm asking "what logically executes an IQueryable to something that returns data"? Background Since I'm doing recursion and I don't want to execute this until the correct time, what is the correct way to merge the results if called multiple times? If it matters I'm thinking of running this command to launch all the tasks var AllRunningDataTasks = results.ToList(); followed by this code: while (AllRunningDataTasks.Count > 0) { // Identify the first task that completes. Task<TableResult> firstFinishedTask = await Task.WhenAny(AllRunningDataTasks); // ***Remove the selected task from the list so that you don't // process it more than once. AllRunningDataTasks.Remove(firstFinishedTask); // TODO: Await the completed task. var taskOfTableResult = await firstFinishedTask; // Todo: (doen't work) TrustState thisState = (TrustState)firstFinishedTask.AsyncState; // TODO: Update the concurrent dictionary with data // thisState.QueryStartPoint + thisState.ThingToSearchFor Interlocked.Decrement(ref thisState.RunningDirectQueries); Interlocked.Increment(ref thisState.CompletedDirectQueries); if (thisState.RunningDirectQueries == 0) { thisState.TimeCompleted = DateTime.UtcNow; } }

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  • Working with fields which can mutate or be new instances altogether

    - by dotnetdev
    Structs are usually used for immutable data, eg a phone number, which does not mutate, but instead you get a new one (eg the number 000 becoming 0001 would mean two seperate numbers). However, pieces of information like Name, a string, can either mutate (company abc changing its name to abcdef, or being given a new name like def). For fields like this, I assume they should reside in the mutable class and not an immutable structure? My way of structuring code is to have an immutable concept, like Address (any change is a new address completely), in a struct and then reference it from a class like Customer, since Customer always has an address. So I would put CompanyName, or Employer, in the class as it is mutable. But a name can either mutate and so be the same 1 instance, or a new name setup and while the company still owning the first name too. Would the correct pattern for assigning a new instance (eg a new company name but the old name still owned by the company) be?: string name = ""; string newName = new string(); newName = "new"; name = newName; And a mutation just the standard assignment pattern? Thanks

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  • Creating sublines on Joomla menu items

    - by ploughansen
    In my toplevel menu items, I would like to make a subline for each item. I don't think it's possible to do by default, byt YooTheme has done it in many of their templates. The menu output look like this <div class="moduletable_menu"> <ul id="mainmenu" class="menu"> <li class="active item1" id="current"> <a href="URL_HIDDEN"> <span>Services</span> </a> </li> </ul> This basically outputs a one line menu item like so: Services What I would like to do is have a menu item like this: Services Service x, Service y, Service z For reference, have a look at the main menu on the YooTheme demo page. The way YooTheme does this, is using two pipes (||) as a linebreak, so in the Joomla backend you type "Services||Service x, Service y, Service z" as the menu title, and then there must be some fancy javascript that breaks this title into two spans, ready to be styled using css. Does anyone know of an easy way to code this? Please note that I am looking to build this feature into a custom template (ie. non-yootheme). Also note that I am not using MooTools, but Jquery instead.

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  • How can I use a compound condition in a join in Linq?

    - by Gary McGill
    Let's say I have a Customer table which has a PrimaryContactId field and a SecondaryContactId field. Both of these are foreign keys that reference the Contact table. For any given customer, either one or two contacts may be stored. In other words, PrimaryContactId can never be NULL, but SecondaryContactId can be NULL. If I drop my Customer and Contact tables onto the "Linq to SQL Classes" design surface, the class builder will spot the two FK relationships from the Customer table to the Contact table, and so the generated Customer class will have a Contact field and a Contact1 field (which I can rename to PrimaryContact and SecondaryContact to avoid confusion). Now suppose that I want to get details of all the contacts for a given set of customers. If there was always exactly one contact then I could write something like: from customer in customers join contact in contacts on customer.PrimaryContactId equals contact.id select ... ...which would be translated into something like: SELECT ... FROM Customer INNER JOIN Contact ON Customer.FirstSalesPersonId = Contact.id But, because I want to join on both the contact fields, I want the SQL to look something like: SELECT ... FROM Customer INNER JOIN Contact ON Customer.FirstSalesPersonId = Contact.id OR Customer.SecondSalesPersonId = Contact.id How can I write a Linq expression to do that?

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  • Compilation problem in the standard x86_64 libraries

    - by user350282
    Hi everyone, I am having trouble compiling a program I have written. I have two different files with the same includes but only one generates the following error when compiled with g++ /usr/lib/gcc/x86_64-linux-gnu/4.4.1/../../../../lib/crt1.o: In function `_start': /build/buildd/eglibc-2.10.1/csu/../sysdeps/x86_64/elf/start.S:109: undefined reference to `main' collect2: ld returned 1 exit status The files I am including in my header are as follows: #include <google/sparse_hash_map> using google::sparse_hash_map; #include <ext/hash_map> #include <math.h> #include <iostream> #include <queue> #include <vector> #include <stack> using std::priority_queue; using std::stack; using std::vector; using __gnu_cxx::hash_map; using __gnu_cxx::hash; using namespace std; Searching the internet for those two lines hasn't resulted in anything to help me. I would be very grateful for any advice. Thank you

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  • Testing ActionMailer's receive method (Rails)

    - by Brian Armstrong
    There is good documentation out there on testing ActionMailer send methods which deliver mail. But I'm unable to figure out how to test a receive method that is used to parse incoming mail. I want to do something like this: require 'test_helper' class ReceiverTest < ActionMailer::TestCase test "parse incoming mail" do email = TMail::Mail.parse(File.open("test/fixtures/emails/example1.txt",'r').read) assert_difference "ProcessedMail.count" do Receiver.receive email end end end But I get the following error on the line which calls Receiver.receive NoMethodError: undefined method `index' for #<TMail::Mail:0x102c4a6f0> /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/stringio.rb:128:in `gets' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/mail.rb:392:in `parse_header' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/mail.rb:139:in `initialize' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/stringio.rb:43:in `open' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/port.rb:340:in `ropen' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/mail.rb:138:in `initialize' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/mail.rb:123:in `new' /Library/Ruby/Gems/1.8/gems/tmail-1.2.7.1/lib/tmail/mail.rb:123:in `parse' /Library/Ruby/Gems/1.8/gems/actionmailer-2.3.4/lib/action_mailer/base.rb:417:in `receive' Tmail is parsing the test file I have correctly. So that's not it. Thanks!

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  • PHP DELETE immediately after select

    - by teehoo
    I have a PHP server script that SELECTs some data from a MySQL database. As soon as I have the result from mysql_query and mysql_fetch_assoc stored in my own local variables, I want to delete the row I just selected. The problem with this approach is that it seems that PHP has done pass-by-reference to my local variables instead of pass-by-value, and my local variables become undefined after the delete command. Is there anyway to get around this? Here is my code: $query="SELECT id, peerID, name FROM names WHERE peer = $userID AND docID = '$docID' AND seqNo = $nid"; $result = mysql_query($query); if (!$result) self::logError("FAIL:1 getUsersNamesUpdate() query: ".$query."\n"); if (mysql_num_rows($result) == 0) return array(); $row = mysql_fetch_assoc($result); $result = array(); $result["id"] = $row["id"]; $result["peerID"] = $row["peerID"]; $result["name"] = $row["name"]; $query="DELETE FROM names WHERE id = $result[id];"; $result = mysql_query($query); if (!$result) self::logError("FAIL:2 getUsersNamesUpdate() query: ".$query."\n"); return $result;

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  • Eliminate full table scan due to BETWEEN (and GROUP BY)

    - by Dave Jarvis
    Description According to the explain command, there is a range that is causing a query to perform a full table scan (160k rows). How do I keep the range condition and reduce the scanning? I expect the culprit to be: Y.YEAR BETWEEN 1900 AND 2009 AND Code Here is the code that has the range condition (the STATION_DISTRICT is likely superfluous). SELECT COUNT(1) as MEASUREMENTS, AVG(D.AMOUNT) as AMOUNT, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, STATION_DISTRICT SD, YEAR_REF Y FORCE INDEX(YEAR_IDX), MONTH_REF M, DAILY D WHERE -- For a specific city ... -- C.ID = 10663 AND -- Find all the stations within a specific unit radius ... -- 6371.009 * SQRT( POW(RADIANS(C.LATITUDE_DECIMAL - S.LATITUDE_DECIMAL), 2) + (COS(RADIANS(C.LATITUDE_DECIMAL + S.LATITUDE_DECIMAL) / 2) * POW(RADIANS(C.LONGITUDE_DECIMAL - S.LONGITUDE_DECIMAL), 2)) ) <= 50 AND -- Get the station district identification for the matching station. -- S.STATION_DISTRICT_ID = SD.ID AND -- Gather all known years for that station ... -- Y.STATION_DISTRICT_ID = SD.ID AND -- The data before 1900 is shaky; insufficient after 2009. -- Y.YEAR BETWEEN 1900 AND 2009 AND -- Filtered by all known months ... -- M.YEAR_REF_ID = Y.ID AND -- Whittled down by category ... -- M.CATEGORY_ID = '003' AND -- Into the valid daily climate data. -- M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR Update The SQL is performing a full table scan, which results in MySQL performing a "copy to tmp table", as shown here: +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | 1 | SIMPLE | C | const | PRIMARY | PRIMARY | 4 | const | 1 | | | 1 | SIMPLE | Y | range | YEAR_IDX | YEAR_IDX | 4 | NULL | 160422 | Using where | | 1 | SIMPLE | SD | eq_ref | PRIMARY | PRIMARY | 4 | climate.Y.STATION_DISTRICT_ID | 1 | Using index | | 1 | SIMPLE | S | eq_ref | PRIMARY | PRIMARY | 4 | climate.SD.ID | 1 | Using where | | 1 | SIMPLE | M | ref | PRIMARY,YEAR_REF_IDX,CATEGORY_IDX | YEAR_REF_IDX | 8 | climate.Y.ID | 54 | Using where | | 1 | SIMPLE | D | ref | INDEX | INDEX | 8 | climate.M.ID | 11 | Using where | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ Related http://dev.mysql.com/doc/refman/5.0/en/how-to-avoid-table-scan.html http://dev.mysql.com/doc/refman/5.0/en/where-optimizations.html http://stackoverflow.com/questions/557425/optimize-sql-that-uses-between-clause Thank you!

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  • WPF or Silverlight Learning Resources for Business Applications

    - by Refracted Paladin
    I am the only developer at a non-profit organization(~200 employees) where we are a M$ shop and 90% of the things I develop are specific to our company and are internal only. I am given a lot of latitude on how I accomplish my goals so using new technologies is in my best interest. So far I have developed all winform & asp.net applications. I would now like to focus on XAML driven development(WPF & Silverlight) and would like your help. I am subscribed to numerous Silverlight blogs and I have went through a few good tutorials however, I would really appreciate a GOOD SOLID book in my hands going forward. I prefer learning books versus reference books and I REALLY would like one from a Business standpoint as well. Shameless, self-promoting is welcomed if you happen to be an author or reviewer for one that meets my criteria. I would, however, prefer that recomendations were based on first-hand experience(no, 'my friend as this awesome book he told me about', please). Though, I don't mind un-released books if say they are an updated version of an existing. disclaimer -- I know there are an insane amount of Book posts here(SO) but none I believe for my specific need. If there is and I missed it I apologize.

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  • Out of memory when creating a lot of objects C#

    - by Bas
    I'm processing 1 million records in my application, which I retrieve from a MySQL database. To do so I'm using Linq to get the records and use .Skip() and .Take() to process 250 records at a time. For each retrieved record I need to create 0 to 4 Items, which I then add to the database. So the average amount of total Items that has to be created is around 2 million. while (objects.Count != 0) { using (dataContext = new LinqToSqlContext(new DataContext())) { foreach (Object objectRecord in objects) { // Create a list of 0 - 4 Random Items and add each Item to the Object for (int i = 0; i < Random.Next(0, 4); i++) { Item item = new Item(); item.Id = Guid.NewGuid(); item.Object = objectRecord.Id; item.Created = DateTime.Now; item.Changed = DateTime.Now; dataContext.InsertOnSubmit(item); } } dataContext.SubmitChanges(); } amountToSkip += 250; objects = objectCollection.Skip(amountToSkip).Take(250).ToList(); } Now the problem arises when creating the Items. When running the application (and not even using dataContext) the memory increases consistently. It's like the items are never getting disposed. Does anyone notice what I'm doing wrong? Thanks in advance!

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  • What's the SQL function for timestamp manipulation?

    - by Eric Leroy
    I'm new to SQL and the time functions are different than mySQL so I'm having a terrible time finding a good site reference with USEFUL timestamp queries. I'm not able to locate the correct way of doing this query in SQL: Id Timestamp ----------------------------------- 1145744 2012-10-10 18:15:11.500 1145743 2012-10-10 18:15:11.313 1145742 2012-10-10 18:15:11.313 1145741 2012-10-10 18:15:11.253 1145740 2012-10-10 18:15:11.190 1145739 2012-10-10 18:15:11.190 1145738 2012-10-10 18:15:11.127 1145737 2012-10-10 18:15:11.067 1145736 2012-10-10 18:15:11.063 1145735 2012-10-10 18:15:10.940 1145734 2012-10-10 18:15:10.817 SELECT * from table WHERE Timestamp ... RANGE I need the range of 2 timestamps so I can select rows by the following parameters: second range minute range hour range day range week range month range year range Is there one function to put in 2 timestamps and get the range? or is this a mix of functions I need? Any good site references would be greatly appriceated. MSDN site isn't helping me isolate the proper way of doing this. I've been searching for about an hour trying to get the last day from 1:30PM to 1:30PM today.

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  • Does "delegate" mean a type or an object?

    - by Michal Czardybon
    Reading from MSDN: "A delegate is a type that references a method. Once a delegate is assigned a method, it behaves exactly like that method." Does then "delegate" mean a type or an object?! ...It cannot be both. It seems to me that the single word is used in two different meanings: a type containing a reference to a method of some specified signature, an object of that type, which can be actually called like a method. I would prefer a more precise vocabulary and use "delegate type" for the first case. I have been recently reading a lot about events and delegates and that ambiguity was making me confused many times. Some other uses of "delegate" word in MSDN in the first meaning: "Custom event delegates are needed only when an event generates event data" "A delegate declaration defines a class that is derived from the class System.Delegate" Some other uses of "delegate" word in MSDN in the second meaning: "specify a delegate that will be called upon the occurrence of some event" "Delegates are objects that refer to methods. They are sometimes described as type-safe function pointers" What do you think? Why did people from Microsoft introduced this ambiguity? Am I the only person to have conceptual problems with different notions being referenced with the same word.

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  • Mouse management in JavaScript games

    - by Jakob
    Im using JavaScript, the HTML5 canvas-element and WebGL to make a simple 3D-game in first person view for fun. Ideally, I would like to control my movement by using the keyboard to move and the mouse to look around, like you usually do in FPS-games. As you probably understand, there are some limits to this in the browser, since the mouse cant be captured: When using the onmousemove event, no further movement will be detected when the mouse pointer reaches the border of my screen (which means that I wont be able to run in a circle for example) Seeing the mouse move across the screen is not the end of the world, but it is a little annoying From what I know, it's impossible to hide the mouse as well as setting it's position in JavaScript. Hence, my question is this: If we cant to those things, what can we do in order to get close to the desktop gaming experience when it comes to the mouse in the browser? And I mean right now, using current APIs. Not "what could be changed in some standard to make life easier". Also, I realize that I could use the keyboard to look around, but then we're back in 1995 when Quake were actually played like that. And of course I know that it would be easier to write a desktop application or use Flash at least, but Im trying to push JavaScript's limits here. Apart from those things, what are your suggestions? Any kind of reference, existing game, crazy idea, hack or even browser specific solution would be appreciated.

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