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  • Entity Framework - Many to Many Subquery

    - by Jorin
    I asked a question about this previously but my database structure has changed, and while it made other things simpler, now this part is more complicated. Here is the previous question. At the time, my EF Context had a UsersProjects object because there were other properties. Now that I've simplified that table, it is just the keys, so all my EF context knows about is Users and Projects and the M2M relationship between them. There is no more UsersProjects as far as EF knows. So my goal is to say "show me all the users who are working on projects with me." in SQL, this would go something like: SELECT * FROM Users INNER JOIN UsersProjects ON Users.ID=UsersProjects.UserID WHERE ProjectID IN (SELECT ProjectID FROM UsersProjects WHERE UserID=@UserID) and I started in EF with something like this: var myProjects = (from p in edmx.Projects where p.Users.Contains(edmx.Users.FirstOrDefault(u => u.Email == UserEmail)) orderby p.Name select p).ToList(); var associatedUsers = (from u in edmx.Users where myProjects.Contains(?????????) //where myProjects.Any(????????) select u); The trick is finding what to put in the ????????. Anyone help here?

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  • Creating reusable chunks of Linq to SQL

    - by tia
    Hi, I am trying to break up horrible linq to sql queries to make them a bit more readable. Say I want to return all orders for product which in the previous year had more than 100 orders. So, original query is: from o in _context.Orders where (from o1 in _context.Orders where o1.Year == o.Year - 1 && o1.Product == o.Product select o1).Count() > 100 select o; Messy. What I'd like to be able to do is to be able to break it down, eg: private IEnumerable<Order> LastSeasonOrders(Order order) { return (from o in _context.Orders where o.Year == order.Year - 1 && o.Product == order.Product select o); } which then lets me change the original query to: from o in _context.Orders where LastSeasonOrders(o).Count() > 100 select o; This doesn't seem to work, as I get method Blah has no supported translation to SQL when the query is run. Any quick tips on the correct way to achieve this?

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  • LINQ to objects: Is there

    - by Charles
    I cannot seem to find a way to have LINQ return the value from a specified accessor. I know the name of the accessors for each object, but am unsure if it is possible to pass the requested accessor as a variable or otherwise achieve the desired refactoring. Consider the following code snippet: // "value" is some object with accessors like: format, channels, language row = new List<String> { String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.format).ToArray()), String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.channels).ToArray()), String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.language).ToArray()), // ... } I'd like to refactor this into a method that uses the specified accessor, or perhaps pass a delegate, though I don't see how that could work. string niceRefactor(myObj myObject, string /* or whatever type */ ____ACCESSOR) { return String.Join(innerSeparator, (from item in myObject.Audio orderby item.Key ascending select item.Value.____ACCESSOR).ToArray()); } I have written a decent amount of C#, but am still new to the magic of LINQ. Is this the right approach? How would you refactor this?

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  • Problem convert column values from VARCHAR(n) to DECIMAL

    - by Kevin Babcock
    I have a SQL Server 2000 database with a column of type VARCHAR(255). All the data is either NULL, or numeric data with up to two points of precision (e.g. '11.85'). I tried to run the following T-SQL query but received the error 'Error converting data type varchar to numeric' SELECT CAST([MyColumn] AS DECIMAL) FROM [MyTable]; I tried a more specific cast, which also failed. SELECT CAST([MyColumn] AS DECIMAL(6,2)) FROM [MyTable]; I also tried the following to see if any data is non-numeric, and the only values returned were NULL. SELECT ISNUMERIC([MyColumn]), [MyColumn] FROM [MyTable] WHERE ISNUMERIC([MyColumn]) = 0; I tried to convert to other data types, such as FLOAT and MONEY, but only MONEY was successful. So I tried the following: SELECT CAST(CAST([MyColumn] AS MONEY) AS DECIMAL) FROM [MyTable]; ...which worked just fine. Any ideas why the original query failed? Will there be a problem if I first convert to MONEY and then to DECIMAL? Thanks!

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  • I have a problem with mysql and php

    - by neo skosana
    Hi I have a problem, this is my code: $db = new mysqli("localhost", "root", "", "blah"); $result1 = $db-query("select * from c_register where email = '$eml' and password = '$pass'"); if($result1-fetch_array()) { $auth->createSession(); $_SESSION['user'] = 'client'; promptUser("You have successfully logged in!!!","index.php"); } $db = new mysqli("localhost", "root", "", "blah"); $result2 = $db-query("select * from b_register where email = '$eml' and password = '$pass'"); if($result2-fetch_array()) { $auth->createSession(); $_SESSION['user'] = 'business'; promptUser("You have successfully logged in!!!","index.php"); } $db = new mysqli("localhost", "root", "", "blah"); $result3 = $db-query("select * from g_register where email = '$eml' and password = '$pass'"); if($result3-fetch_array()) { $auth->createSession(); $_SESSION['user'] = 'employee'; promptUser("You have successfully logged in!!!","index.php"); } $db = new mysqli("localhost", "root", "", "blah"); $result4 = $db-query("select * from k_register where email = '$eml' and password = '$pass'"); if($result4-fetch_array()) { $auth->createSession(); $_SESSION['user'] = 'super'; promptUser("You have successfully logged in!!!","index.php"); } else { promptUser("Username/Password do not match. Please try again!!!",""); } Funny enough this code works, but I no that I went about it the wrong way. I am new with php and mysql, so please help. I also tried e.gresult4->free(); for all the variable that save the data, and I got this error: Fatal error: Call to a member function free() on a non-object in...

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  • Lost Array After Validation Error

    - by Georges Kmeid
    I'm working on a CakePHP project and I have User, Post and Location models among others. User hasMany Location and Post belongsTo User so Location is not directly related to Post. This is my code in the Post controller: public function add() { if ($this->request->is('get')) { $this->loadModel('Location'); $this->set('locations', $this->Location->find('all', array('conditions' => array('user_id' => $this->Auth->user('id'))))); } ... } And this is my code in the posts/add view: <?php $i = 0; $j = 0; foreach ($locations as $location): $location_names[$i] = $location['Location']['name']; $i++; endforeach; echo "<select name=\"location\" onchange=\"select(this.value)\">"; echo "<option value=\"\">Select a saved location</option>"; foreach ($locations as $location): echo "<option value=\"" . $location['Location']['latitude'] . "," . $location['Location']['longitude'] . "\">" . $location_names[$j] . "</option>"; $j++; endforeach; ?> </select> If I enter a wrong value in one of the post inputs that has a validation rule in Post model, it redirects to the current add view, shows what is the validation error, but then the $locations array passed from controller to view disappears and can't use it in view and I get this error: Notice (8): Undefined variable: locations [APP\View\Posts\add.ctp, line 68]

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  • Django: DatabaseError column does not exist

    - by Rosarch
    I'm having a problem with Django 1.2.4. Here is a model: class Foo(models.Model): # ... ftw = models.CharField(blank=True) bar = models.ForeignKey(Bar) Right after flushing the database, I use the shell: Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39) [GCC 4.4.5] on linux2 Type "help", "copyright", "credits" or "license" for more information. (InteractiveConsole) >>> from apps.foo.models import Foo >>> Foo.objects.all() Traceback (most recent call last): File "<console>", line 1, in <module> File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 67, in __repr__ data = list(self[:REPR_OUTPUT_SIZE + 1]) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 82, in __len__ self._result_cache.extend(list(self._iter)) File "/usr/local/lib/python2.6/dist-packages/django/db/models/query.py", line 271, in iterator for row in compiler.results_iter(): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/compiler.py", line 677, in results_iter for rows in self.execute_sql(MULTI): File "/usr/local/lib/python2.6/dist-packages/django/db/models/sql/compiler.py", line 732, in execute_sql cursor.execute(sql, params) File "/usr/local/lib/python2.6/dist-packages/django/db/backends/util.py", line 15, in execute return self.cursor.execute(sql, params) File "/usr/local/lib/python2.6/dist-packages/django/db/backends/postgresql_psycopg2/base.py", line 44, in execute return self.cursor.execute(query, args) DatabaseError: column foo_foo.bar_id does not exist LINE 1: ...t_omg", "foo_foo"."ftw", "foo_foo... What am I doing wrong here?

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  • Why NOT use POST method here?

    - by Camran
    I have a classifieds website. In the main page (index) I have several form fields which the user may or may not fill in, in order to specify a detailed search of classifieds. Ex: Category: Cars Price from: 3000 Price to: 10000 Color: Red Area: California The forms' action is set to a php page: <form action='query_sql.php' method='post'> In query_sql.php I fetch the variables like this: category=$_POST['category']; etc etc... Then query MySql: $query="SELECT........WHERE category='$category' etc etc.... $results = mysql_query($query); Then I simply display the results of the query to the user by creating a table which is filled in dynamically depending on the results set. However, according to an answer by Col. Shrapnel in my previous Q I shouldn't use POST here: http://stackoverflow.com/questions/3004754/how-to-hide-url-from-users-when-submitting-this-form The reason I use post is simply to hide the "one-page-word-document" long URL in the browsers adress bar. I am very confused, is it okay to use POST or not? It is working fine both when I use GET or POST now... And it is already on a production server... Btw, in the linked question, I wasn't referring to make URL invisible (or hide it) I just wanted it too look better (which I have accomplished with mod_rewrite). UPDATE: If I use GET, then how should I make the url better looking (beautiful)? Check this previous Q out: http://stackoverflow.com/questions/3000524/how-to-make-this-very-long-url-appear-short

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  • 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

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  • how to assign the html value to the php variable without post or get method

    - by Meena
    hi , in my program i had a php value $test = 2 using this value i done some operation for example: in my page i had a 2 block A and B and one select box. If the test value is A it enable the div A, if the value is B it hide div A and also i am able to show and hide the div using the select box onchange event. please check my sample code given below $test = $_GET["id"]; <select name="hideme" id="hideme" onchange="enableme();"> <option value="A">Show</option> <option value="B">Hide</option> </select> if($test == 'A') { <div id="div1" name="div1"> xxxxxxxxxxxxx </div> } Js Function : function enableme() { if(document.getElementByID('hideme').value == "A") { document.getElementById.style.display ="block"; } else { document.getElementById.style.display ="none"; } } my issue is at fist time using the $test($_get) value it show the correct div but the on change event is not working because of , if condition. If i remove the if condition then it show div A even if the value of the $test is B. how could i handle both. Please Help me

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  • VB.NET Syntax Coding

    - by Yiu Korochko
    I know many people ask how some of these are done, but I do not understand the context in which to use the answers, so... I'm building a code editor for a subversion of Python language, and I found a very decent way of highlighting keywords in the RichTextBox through this: bluwords.Add(KEYWORDS GO HERE) If scriptt.Text.Length > 0 Then Dim selectStart2 As Integer = scriptt.SelectionStart scriptt.Select(0, scriptt.Text.Length) scriptt.SelectionColor = Color.Black scriptt.DeselectAll() For Each oneWord As String In bluwords Dim pos As Integer = 0 Do While scriptt.Text.ToUpper.IndexOf(oneWord.ToUpper, pos) >= 0 pos = scriptt.Text.ToUpper.IndexOf(oneWord.ToUpper, pos) scriptt.Select(pos, oneWord.Length) scriptt.SelectionColor = Color.Blue pos += 1 Loop Next scriptt.SelectionStart = selectStart2 End If (scriptt is the richtextbox) But when any decent amount of code is typed (or loaded via OpenFileDialog) chunks of the code go missing, the syntax selection falls apart, and it just plain ruins it. I'm looking for a more efficient way of doing this, maybe something more like visual studio itself...because there is NO NEED to highlight all text, set it black, then redo all of the syntaxing, and the text begins to over-right if you go back to insert characters between text. Also, in this version of Python, hash (#) is used for comments on comment only lines and double hash (##) is used for comments on the same line. Now I saw that someone had asked about this exact thing, and the working answer to select to the end of the line was something like: ^\'[^\r\n]+$|''[^\r\n]+$ which I cannot seem to get into practice. I also wanted to select text between quotes and turn it turquoise, such as between the first quotation mark and the second, the text is turquoise, and the same between the 3rd and 4th etcetera... Any help is appreciated!

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  • MS SQL - Multi-Column substring matching

    - by hamlin11
    One of my clients is hooked on multi-column substring matching. I understand that Contains and FreeText search for words (and at least in the case of Contains, word prefixes). However, based upon my understanding of this MSDN book, neither of these nor their variants are capable of searching substrings. I have used LIKE rather extensively (Select * from A where A.B Like '%substr%') Sample table A: ID | Col1 | Col2 | Col3 | ------------------------------------- 1 | oklahoma | colorado | Utah | 2 | arkansas | colorado | oklahoma | 3 | florida | michigan | florida | ------------------------------------- The following code will give us row 1 and row 2: select * from A where Col1 like '%klah%' or Col2 like '%klah%' or Col3 like '%klah%' This is rather ugly, probably slow, and I just don't like it very much. Probably because the implementations that I'm dealing with have 10+ columns that need searched. The following may be a slight improvement as code readability goes, but as far as performance, we're still in the same ball park. select * from A where (Col1 + ' ' + Col2 + ' ' + Col3) like '%klah%' I have thought about simply adding insert, update, and delete triggers that simply add the concatenated version of the above columns into a separate table that shadows this table. Sample Shadow_Table: ID | searchtext | --------------------------------- 1 | oklahoma colorado Utah | 2 | arkansas colorado oklahoma | 3 | florida michigan florida | --------------------------------- This would allow us to perform the following query to search for '%klah%' select * from Shadow_Table where searchtext like '%klah%' I really don't like having to remember that this shadow table exists and that I'm supposed to use it when I am performing multi-column substring matching, but it probably yields pretty quick reads at the expense of write and storage space. My gut feeling tells me there there is an existing solution built into SQL Server 2008. However, I don't seem to be able to find anything other than research papers on the subject. Any help would be appreciated.

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  • Amazon Product API ResponseGroups and Default results

    - by aboxy
    A. In our application, most of the data we work with is stored as free text .i.e. there is no categorization done as of now. We are using openNLP libraries to make sense of the data(extract keywords/classify) and do a query to Amazon web services to pull the results of the query. We use searchindex=All and keywords=. Results are not always returned and we basically get 'AWS.ECommerceService.NoExactMatches' How to avoid that? 1) Is there a way to specify default results if no match found? e.g. Amazon carousel widget does that if the search query did not return results, it basically show some computer items. 2) Should I batch the request always and add another search criteria to every request? If my first criteria does not pull any results, we can be sure that our 2nd query will always pull results(possibly caching?) Here is one search criteria 'Open Circle Hoop Earrings Polished Stainless Steel Open Circle Hoop Earrings Polished Stainless Steel DiamondShark' This return no results via API. On Amazon site,I get alternative suggestions with some results which are pretty relevant. Is there a way to pull those results? B. We just need a thumbnail image and a title and description for our app. Which responseGroup is appropriate? We are using medium rt now but there is awful lot of information even with that responseGroup. Any help is appreciated. thanks

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  • Is there any performance issue using Row_Number to implement table paging in Sql Server 2008?

    - by majkinetor
    I want to implement table paging using this method: SET @PageNum = 2; SET @PageSize = 10; WITH OrdersRN AS ( SELECT ROW_NUMBER() OVER(ORDER BY OrderDate, OrderID) AS RowNum ,* FROM dbo.Orders ) SELECT * FROM OrdersRN WHERE RowNum BETWEEN (@PageNum - 1) * @PageSize + 1 AND @PageNum * @PageSize ORDER BY OrderDate ,OrderID; Is there anything I should be aware of ? Table has millions of records. Thx. EDIT: After using suggested MAXROWS method for some time (which works really really fast) I had to switch back to ROW_NUMBER method because of its greater flexibility. I am also very happy about its speed so far (I am working with View having more then 1M records with 10 columns). To use any kind of query I use following modification: PROCEDURE [dbo].[PageSelect] ( @Sql nvarchar(512), @OrderBy nvarchar(128) = 'Id', @PageNum int = 1, @PageSize int = 0 ) AS BEGIN SET NOCOUNT ON Declare @tsql as nvarchar(1024) Declare @i int, @j int if (@PageSize <= 0) OR (@PageSize > 10000) SET @PageSize = 10000 -- never return more then 10K records SET @i = (@PageNum - 1) * @PageSize + 1 SET @j = @PageNum * @PageSize SET @tsql = 'WITH MyTableOrViewRN AS ( SELECT ROW_NUMBER() OVER(ORDER BY ' + @OrderBy + ') AS RowNum ,* FROM MyTableOrView WHERE ' + @Sql + ' ) SELECT * FROM MyTableOrViewRN WHERE RowNum BETWEEN ' + CAST(@i as varchar) + ' AND ' + cast(@j as varchar) exec(@tsql) END If you use this procedure make sure u prevented sql injection.

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  • Retrieve only the superclass from a class hierarchy

    - by user1792724
    I have an scenario as the following: @Entity @Table(name = "ANIMAL") @Inheritance(strategy = InheritanceType.JOINED) public class Animal implements Serializable { @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "S_ANIMAL") @SequenceGenerator(name = "S_ANIMAL", sequenceName = "S_ANIMAL", allocationSize = 1) public int getNumero() { return numero; } public void setNumero(int numero) { this.numero = numero; } . . . } and as the subclass: @Entity @Table(name = "DOG") public class Dog extends Animal { private static final long serialVersionUID = -7341592543130659641L; . . . } I have a JPA Select statement like this: SELECT a FROM Animal a; I'm using Hibernate 3.3.1 As I can see the framework retrieves instances of Animal and also of Dog using a left outer join. Is there a way to Select only the "part" Animal? I mean, the previous Select will get all the Animals, those that are only Animals but not Dogs and those that are Dogs. I want them all, but in the case of Dogs I want to only retrieve the "Animal part" of them. I found the @org.hibernate.annotations.Entity(polymorphism = PolymorphismType.EXPLICIT) but as I could see this only works if Animal isn't an @Entity. Thanks a lot.

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  • linq delegate function checking from objects

    - by Philip
    I am trying to find the list of objects which can be replaced. Class Letter{ int ID; string Name; string AdvCode; int isDeleted; } Class Replacers{ int ID; string MainAdvCode; string ReplacesAdvCode; } example data: Replacers 0 455 400 1 955 400 2 955 455 such that if a Letter has and Advcode of 455 and another has a code of 400 the 400 gets marked for deletion. And then if another Letter has a 955 then the 455 gets marked for deletion and the 400 (which is already marked) is marked for deletion. The problem is with my current code the 400 and 455 is marking itself for deletion?!?!? Public class Main{ List<Letter> Letters; List<Replacers> replaces; //select the ones to replace the replacements aka the little guys //check if the replacements replacer exists if yes mark deleted var filterMethodReplacements = new Func<Letter, bool>(IsAdvInReplacements);//Working var filterMethodReplacers = new Func<Letter, bool>(IsAdvInReplacers);//NOT WORKING???? var resReplacements=letters.Where(filterMethodReplacements);//working foreach (Letter letter in resReplacements) { //select the Replacers aka the ones that contain the little guys var resReplacers = letters.Where(filterMethodReplacers); if (resReplacers != null) letter.isDeleted = 1; } } } private bool IsAdvInReplacements(Letter letter) { return (from a in Replacables where a.ReplaceAdvCode == letter.AdvCode select a).Any(); } private bool IsAdvInReplacers(Letter letter) { //?????????????????????????????? return (from a in Replacables where a.MainAdvCode == letter.AdvCode select a).Any(); } }

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  • Drupal 6 - I am using drupal_execute to insert a CCK node into my site. Everything is working excep

    - by rdurbin
    $form_state['values']['field_prx_mp3_labels'][0][value] = $mp3_labels; $form_state['values']['taxonomy'][0][value] = array('tags'=>array('1'=>'Music')); $errs = drupal_execute('prx_content_node_form', $form_state, (object) $nodeTmp); This is a Drupal 6 site. I am using drupal_execute to create a node programatically. The first line is working for field_prx_mp3_labels. The second (for taxonomy) is not. Here is what my select on the node add for my cck looks like: <select name="taxonomy[2][]" multiple="multiple" class="form-select" id="edit-taxonomy-2" size="9"><option value="">- None -</option><option value="5">Music</option><option value="6">-Rock/Pop</option><option value="7">-Jazz/Blues</option><option value="8">-Classical</option><option value="9">-Music Documentaries</option><option value="10">-Festivals/Concerts</option><option value="11">Arts</option><option value="19">-Literature</option><option value="12">Nature</option><option value="13">History</option><option value="15">-Music</option><option value="14">Culture</option><option value="17">-American Indian</option><option value="18">-Latino</option><option value="16">-Youth Perspective</option></select> I have tried many many variations for line 2 (relating to the taxonomy). This comment seemed close but it hasn't worked for me: http://drupal.org/node/178506#comment-1155576 Thanks!

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  • Merge computed data from two tables back into one of them

    - by Tyler McHenry
    I have the following situation (as a reduced example). Two tables, Measures1 and Measures2, each of which store an ID, a Weight in grams, and optionally a Volume in fluid onces. (In reality, Measures1 has a good deal of other data that is irrelevant here) Contents of Measures1: +----+----------+--------+ | ID | Weight | Volume | +----+----------+--------+ | 1 | 100.0000 | NULL | | 2 | 200.0000 | NULL | | 3 | 150.0000 | NULL | | 4 | 325.0000 | NULL | +----+----------+--------+ Contents of Measures2: +----+----------+----------+ | ID | Weight | Volume | +----+----------+----------+ | 1 | 75.0000 | 10.0000 | | 2 | 400.0000 | 64.0000 | | 3 | 100.0000 | 22.0000 | | 4 | 500.0000 | 100.0000 | +----+----------+----------+ These tables describe equivalent weights and volumes of a substance. E.g. 10 fluid ounces of substance 1 weighs 75 grams. The IDs are related: ID 1 in Measures1 is the same substance as ID 1 in Measures2. What I want to do is fill in the NULL volumes in Measures1 using the information in Measures2, but keeping the weights from Measures1 (then, ultimately, I can drop the Measures2 table, as it will be redundant). For the sake of simplicity, assume that all volumes in Measures1 are NULL and all volumes in Measures2 are not. I can compute the volumes I want to fill in with the following query: SELECT Measures1.ID, Measures1.Weight, (Measures2.Volume * (Measures1.Weight / Measures2.Weight)) AS DesiredVolume FROM Measures1 JOIN Measures2 ON Measures1.ID = Measures2.ID; Producing: +----+----------+-----------------+ | ID | Weight | DesiredVolume | +----+----------+-----------------+ | 4 | 325.0000 | 65.000000000000 | | 3 | 150.0000 | 33.000000000000 | | 2 | 200.0000 | 32.000000000000 | | 1 | 100.0000 | 13.333333333333 | +----+----------+-----------------+ But I am at a loss for how to actually insert these computed values into the Measures1 table. Preferably, I would like to be able to do it with a single query, rather than writing a script or stored procedure that iterates through every ID in Measures1. But even then I am worried that this might not be possible because the MySQL documentation says that you can't use a table in an UPDATE query and a SELECT subquery at the same time, and I think any solution would need to do that. I know that one workaround might be to create a new table with the results of the above query (also selecting all of the other non-Volume fields in Measures1) and then drop both tables and replace Measures1 with the newly-created table, but I was wondering if there was any better way to do it that I am missing.

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  • Python : How to close a UDP socket while is waiting for data in recv ?

    - by alexroat
    Hello, let's consider this code in python: import socket import threading import sys import select class UDPServer: def __init__(self): self.s=None self.t=None def start(self,port=8888): if not self.s: self.s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM) self.s.bind(("",port)) self.t=threading.Thread(target=self.run) self.t.start() def stop(self): if self.s: self.s.close() self.t.join() self.t=None def run(self): while True: try: #receive data data,addr=self.s.recvfrom(1024) self.onPacket(addr,data) except: break self.s=None def onPacket(self,addr,data): print addr,data us=UDPServer() while True: sys.stdout.write("UDP server> ") cmd=sys.stdin.readline() if cmd=="start\n": print "starting server..." us.start(8888) print "done" elif cmd=="stop\n": print "stopping server..." us.stop() print "done" elif cmd=="quit\n": print "Quitting ..." us.stop() break; print "bye bye" It runs an interactive shell with which I can start and stop an UDP server. The server is implemented through a class which launches a thread in which there's a infinite loop of recv/*onPacket* callback inside a try/except block which should detect the error and the exits from the loop. What I expect is that when I type "stop" on the shell the socket is closed and an exception is raised by the recvfrom function because of the invalidation of the file descriptor. Instead, it seems that recvfrom still to block the thread waiting for data even after the close call. Why this strange behavior ? I've always used this patter to implements an UDP server in C++ and JAVA and it always worked. I've tried also with a "select" passing a list with the socket to the xread argument, in order to get an event of file descriptor disruption from select instead that from recvfrom, but select seems to be "insensible" to the close too. I need to have a unique code which maintain the same behavior on Linux and Windows with python 2.5 - 2.6. Thanks.

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  • Mysql for update

    - by shantanuo
    MySQL supports "for update" keyword. Here is how I tested that it is working as expected. I opened 2 browser tabs and executed the following commands in one window. mysql> start transaction; Query OK, 0 rows affected (0.00 sec) mysql> select * from myxml where id = 2 for update; .... mysql> update myxml set id = 3 where id = 2 limit 1; Query OK, 1 row affected, 1 warning (0.00 sec) Rows matched: 1 Changed: 1 Warnings: 0 mysql> commit; Query OK, 0 rows affected (0.08 sec) In another window, I started the transaction and tried to take an update lock on the same record. mysql> start transaction; Query OK, 0 rows affected (0.00 sec) mysql> select * from myxml where id = 2 for update; Empty set (43.81 sec) As you can see from the above example, I could not select the record for 43 seconds as the transaction was being processed by another application in the Window No 1. Once the transaction was over, I got to select the record, but since the id 2 was changed to id 3 by the transaction that was executed first, no record was returned. My question is what are the disadvantages of using "for update" syntax? If I do not commit the transaction that is running in window 1 will the record be locked for-ever?

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  • Getting the last User ID in Zend Framework

    - by Ryan Murphy
    Using MySQL query browser, I manually made a table called users and input some date in the fields. I set the primary key to id and set it to auto increment. There are 3 rows, the highest id is 3. I then made the following class in the method directory to call upon the data in the table etc. class Application_Model_DbTable_User extends Zend_Db_Table_Abstract { protected $_name = 'user'; public function getLatestUserId() { $id = $this->getAdapter()->lastInsertId(); return $id; } } In the controller I do the following which gets the value generated by the method and lets the view access it: $usersDbModel = new Application_Model_DbTable_User(); $lastUserId = $usersDbModel->getLatestUserId(); $this->view->lastUserId = $lastUserId; In the view I then echo it to display it to the user: echo $this->lastUserId; However, even though my last id in the users table is 3. It displays 0. I have also tried: public function getLatestUserId() { $sql = 'SELECT max(id) FROM user'; $query = $this->query($sql); $result = $query->fetchAll(); return $result; } But this just throws out a server error. What have I done wrong? Am I missing something? Is there another way of doing this?

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  • merge my code with Ajax code>>> problem

    - by sandy
    I want to help me In the following link i found nice code in Ajax http://www.w3schools.com/php/php_ajax_livesearch.asp I want to link my code with the code you see in the link above and replace dropdown list How can I do it for I could not where is it change in code even my code work as Ajax ?? I wish .... I wish .... I wish any somebody can help me <?php include ("connect.php"); print_r($_POST['sector_list']); $member_id = intval($_POST['sector_list']); if($member_id == 0) { // Default choice was selected } else { $res = mysql_query("SELECT * FROM members WHERE MemberID = $member_id LIMIT 1"); if(mysql_num_rows($res) == 0) { // Not a valid member } else { // The member is in the database } } ?> <form method="POST" action=<?php echo $_SERVER["PHP_SELF"]; ?> > <input type="hidden" name="sector" value="sector_list"> <select name="sector_list[]" class="inputstandard" multiple="multiple"> <option size ="40" value="default">send to </option> <?php $result = mysql_query('SELECT * from members') or die(mysql_error()); while ($row = mysql_fetch_assoc($result)) { echo '<option value="' . $row['MemberName'] . '">' . $row['MemberName']. '</option>'; } ?> <input type ="submit" name ="go" value = "go" > </select> </form>

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  • Incorrect syntax inserting data into table

    - by SelectDistinct
    I am having some trouble with my update() method. The idea is that the user Provides a recipe name, ingredients, instructions and then selects an image using Filestream. Once the user clicks 'Add Recipe' this will call the update method, however as things stand I am getting an error which is mentioning the contents of the text box: Here is the update() method code: private void updatedata() { // filesteam object to read the image // full length of image to a byte array try { // try to see if the image has a valid path if (imagename != "") { FileStream fs; fs = new FileStream(@imagename, FileMode.Open, FileAccess.Read); // a byte array to read the image byte[] picbyte = new byte[fs.Length]; fs.Read(picbyte, 0, System.Convert.ToInt32(fs.Length)); fs.Close(); //open the database using odp.net and insert the lines string connstr = @"Server=mypcname\SQLEXPRESS;Database=RecipeOrganiser;Trusted_Connection=True"; SqlConnection conn = new SqlConnection(connstr); conn.Open(); string query; query = "insert into Recipes(RecipeName,RecipeImage,RecipeIngredients,RecipeInstructions) values (" + textBox1.Text + "," + " @pic" + "," + textBox2.Text + "," + textBox3.Text + ")"; SqlParameter picparameter = new SqlParameter(); picparameter.SqlDbType = SqlDbType.Image; picparameter.ParameterName = "pic"; picparameter.Value = picbyte; SqlCommand cmd = new SqlCommand(query, conn); cmd.Parameters.Add(picparameter); cmd.ExecuteNonQuery(); MessageBox.Show("Image successfully saved"); cmd.Dispose(); conn.Close(); conn.Dispose(); Connection(); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } Can anyone see where I have gone wrong with the insert into Recipes query or suggest an alternative approach to this part of the code?

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  • How to filter node list based on the contents of another node list

    - by ~otakuj462
    Hi, I'd like to use XSLT to filter a node list based on the contents of another node list. Specifically, I'd like to filter a node list such that elements with identical id attributes are eliminated from the resulting node list. Priority should be given to one of the two node lists. The way I originally imagined implementing this was to do something like this: <xsl:variable name="filteredList1" select="$list1[not($list2[@id_from_list1 = @id_from_list2])]"/> The problem is that the context node changes in the predicate for $list2, so I don't have access to attribute @id_from_list1. Due to these scoping constraints, it's not clear to me how I would be able to refer to an attribute from the outer node list using nested predicates in this fashion. To get around the issue of the context node, I've tried to create a solution involving a for-each loop, like the following: <xsl:variable name="filteredList1"> <xsl:for-each select="$list1"> <xsl:variable name="id_from_list1" select="@id_from_list1"/> <xsl:if test="not($list2[@id_from_list2 = $id_from_list1])"> <xsl:copy-of select="."/> </xsl:if> </xsl:for-each> </xsl:variable> But this doesn't work correctly. It's also not clear to me how it fails... Using the above technique, filteredList1 has a length of 1, but appears to be empty. It's strange behaviour, and anyhow, I feel there must be a more elegant approach. I'd appreciate any guidance anyone can offer. Thanks.

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  • Cache layer for MVC - Model or controller?

    - by Industrial
    Hi everyone, I am having some second thoughts about where to implement the caching part. Where is the most appropriate place to implement it, you think? Inside every model, or in the controller? Approach 1 (psuedo-code): // mycontroller.php MyController extends Controller_class { function index () { $data = $this->model->getData(); echo $data; } } // myModel.php MyModel extends Model_Class{ function getData() { $data = memcached->get('data'); if (!$data) { $query->SQL_QUERY("Do query!"); } return $data; } } Approach 2: // mycontroller.php MyController extends Controller_class { function index () { $dataArray = $this->memcached->getMulti('data','data2'); foreach ($dataArray as $key) { if (!$key) { $data = $this->model->getData(); $this->memcached->set($key, $data); } } echo $data; } } // myModel.php MyModel extends Model_Class{ function getData() { $query->SQL_QUERY("Do query!"); return $data; } } Thoughts: Approach 1: No multiget/multi-set. If a high number of keys would be returned, overhead would be caused. Easier to maintain, all database/cache handling is in each model Approach 2: Better performancewise - multiset/multiget is used More code required Harder to maintain Tell me what you think!

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