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  • Oracle User definied aggregate function for varray of varchar

    - by baju
    I am trying to write some aggregate function for the varray and I get this error code when I'm trying to use it with data from the DB: ORA-00600 internal error code, arguments: [kodpunp1], [], [], [], [], [], [], [], [], [], [], [] [koxsihread1], [0], [3989], [45778], [], [], [], [], [], [], [], [] Code of the function is really simple(in fact it does nothing ): create or replace TYPE "TEST_VECTOR" as varray(10) of varchar(20) ALTER TYPE "TEST_VECTOR" MODIFY LIMIT 4000 CASCADE create or replace type Test as object( lastVector TEST_VECTOR, STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number, MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number, MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number, MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number ); create or replace type body Test is STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number is begin sctx := Test(TEST_VECTOR()); return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number is begin self.lastVector := value; return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number is begin return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number is begin returnValue := self.lastVector; return ODCIConst.Success; end; end; create or replace FUNCTION test_fn (input TEST_VECTOR) RETURN TEST_VECTOR PARALLEL_ENABLE AGGREGATE USING Test; Next I create some test data: create table t1_test_table( t1_id number not null, t1_value TEST_VECTOR not null, Constraint PRIMARY_KEY_1 PRIMARY KEY (t1_id) ) Next step is to put some data to the table insert into t1_test_table (t1_id,t1_value) values (1,TEST_VECTOR('x','y','z')) Now everything is prepared to perform queries: Select test_fn(TEST_VECTOR('y','x')) from dual Query above work well Select test_fn(t1_value) from t1_test_table where t1_id = 1 Version of Oracle DBMS I use: 11.2.0.3.0 Does anyone tried do such a thing? What can be the reason that it does not work? How to solve it? Thanks in advance for help.

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  • PHP array checkbox and radio default value

    - by Arg Geo
    I have the code below in my wordpress options page. I can't define the default values for checkbox and radio. array( "name" => "Post Thumbnails", "desc" => "Choose if you want to display <strong>post thumbnails</strong> or not.", "id" => $shortname."_post_thumbs", "type" => "checkbox", "std" => "checked" ), array( "name" => "Example", "desc" => " The Descriptions", "id" => $shortname."_case_thumb", "type" => "radio", "options" => array("nothumb" => " Display nothing", "defthumb" => " Display thumbnail"), "std" => "nothumb" ), For the checkbox tried also "std" => "true" and "std" => " "... but didn't work. Thanks!

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  • iPhone: Low memory crash...

    - by MacTouch
    Once again I'm hunting memory leaks and other crazy mistakes in my code. :) I have a cache with frequently used files (images, data records etc. with a TTL of about one week and a size limited cache (100MB)). There are sometimes more then 15000 files in a directory. On application exit the cache writes an control file with the current cache size along with other useful information. If the applications crashes for some reason (sh.. happens sometimes) I have in such case to calculate the size of all files on application start to make sure I know the cache size. My app crashes at this point because of low memory and I have no clue why. Memory leak detector does not show any leaks at all. I do not see any too. What's wrong with the code below? Is there any other fast way to calculate the total size of all files within a directory on iPhone? Maybe without to enumerate the whole contents of the directory? The code is executed on the main thread. NSUInteger result = 0; NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; NSDirectoryEnumerator *dirEnum = [[[NSFileManager defaultManager] enumeratorAtPath:path] retain]; int i = 0; while ([dirEnum nextObject]) { NSDictionary *attributes = [dirEnum fileAttributes]; NSNumber* fileSize = [attributes objectForKey:NSFileSize]; result += [fileSize unsignedIntValue]; if (++i % 500 == 0) { // I tried lower values too [pool drain]; } } [dirEnum release]; dirEnum = nil; [pool release]; pool = nil; Thanks, MacTouch

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  • How to convert string with double high/wide characters to normal string [VC++6]

    - by Shaitan00
    My application typically recieves a string in the following format: " Item $5.69 " Some contants I always expect: - the LENGHT always 20 characters - the start index of the text always [5] - and most importantly the index of the DECIMAL for the price always [14] In order to identify this string correctly I validate all the expected contants listed above .... Some of my clients have now started sending the string with Doube-High / Double-Wide values (pair of characters which represent a single readable character) similar to the following: " Item $x80x90.x81x91x82x92 " For testing I simply scan the string character-by-character, compare char[i] and char[i+1] and replace these pairs with their corresponding single character when a match is found (works fine) as follows: [Code] for (int i=0; i < sData.length(); i++) { char ch = sData[i] & 0xFF; char ch2 = sData[i+1] & 0xFF; if (ch == '\x80' && ch2 == '\x90') zData.replace("\x80\x90", "0"); else if (ch == '\x81' && ch2 == '\x91') zData.replace("\x81\x91", "1"); else if (ch == '\x82' && ch2 == '\x92') zData.replace("\x82\x92", "2"); ... ... ... } [/Code] But the result is something like this: " Item $5.69 " Notice how this no longer matches my expectation: the lenght is now 17 (instead of 20) due to the 3 conversions and the decimal is now at index 13 (instead of 14) due to the conversion of the "5" before the decimal point. Ideally I would like to convert the string to a normal readable format keeping the constants (length, index of text, index of decimal) at the same place (so the rest of my application is re-usable) ... or any other suggestion (I'm pretty much stuck with this)... Is there a STANDARD way of dealing with these type of characters? Any help would be greatly appreciated, I've been stuck on this for a while now ... Thanks,

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  • xml parser not able to read all the nodes of the xml

    - by pankaj
    Hi i am trying to get values from all the nodes of a xml returned from a web service. But my code only reads first node, it does not read it further. code: -(void)parseData{ NuanceAppDelegate *appDel = (NuanceAppDelegate *)[[UIApplication sharedApplication] delegate]; NSString *url = @"http://cmweb.bpomatrix.net/SmartPhoneService.svc/login/"; url = [[[url stringByAppendingString:UserName] stringByAppendingString:@"/"] stringByAppendingString:Password]; url = [[url stringByAppendingString:@"/"] stringByAppendingString:appDel.CPAID]; NSLog(@"log: @%",url); NSURL *loginURL = [NSURL URLWithString:url]; NSXMLParser *home_Parser = [[NSXMLParser alloc] initWithContentsOfURL:loginURL]; [home_Parser setDelegate:self]; dict = [[NSMutableDictionary alloc] init]; [home_Parser parse]; } - (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName attributes:(NSDictionary *)attributeDict{ if([elementName isEqualToString:@"Address"]) addressFound = TRUE; if([elementName isEqualToString:@"Name"]) nameFound = TRUE; if([elementName isEqualToString:@"LoyaltyNum"]) loyaltyNumFound = TRUE; if([elementName isEqualToString:@"City"]) cityFound = TRUE; if([elementName isEqualToString:@"Province"]) proFound = TRUE; if([elementName isEqualToString:@"Zip"]) zipFound = TRUE; //NSLog(@"Response %@",responseFound); } - (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string{ if(addressFound) { [dict setObject:string forKey:@"address"]; addressFound = FALSE; } else if(nameFound) { [dict setObject:string forKey:@"name"]; nameFound = FALSE; } else if(loyaltyNumFound) { [dict setObject:string forKey:@"loyaltyNum"]; loyaltyNumFound = FALSE; } else if(cityFound) { [dict setObject:string forKey:@"city"]; cityFound = FALSE; } else if(proFound) { [dict setObject:string forKey:@"province"]; proFound = FALSE; } else if(zipFound) { [dict setObject:string forKey:@"zip"]; zipFound = FALSE; } } - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName { if([elementName isEqualToString:@"clsUserProfile"]) { [self parsingOver]; } } -(void)parsingOver { NuanceAppDelegate *appDel = (NuanceAppDelegate *)[[UIApplication sharedApplication] delegate]; appDel.dictProfile = dict; }

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  • Why do browsers encode special characters differently with ajax requests?

    - by Andrei Oniga
    I have a web application that reads the values of a few input fields (alphanumeric) and constructs a very simple xml that is passes to the server, using jQuery's $.ajax() method. The template for that xml is: <request> <session>[some-string]</session> <space>[some-string]</space> <plot>[some-string]</plot> ... </request> Sending such requests to the server when the inputs contain Finnish diacritical characters (such as ä or ö) raises a problem in terms of character encoding with different browsers. For instance, if I add the word Käyttötarkoitus" in one of the inputs, here's how Chrome and Firefox send EXACTLY the same request to the server: Chrome: <request> <session>{string-hidden}</session> <space>2080874</space> <plot>Käyttötarkoitus</plot> ... </request> FF 12.0: <request> <session>{string-hidden}</session> <space>2080874</space> <plot>Käyttötarkoitus</plot> ... </request> And here is the code fragment that I use to send the requests: $.ajax({ type: "POST", url: url, dataType: 'xml;charset=UTF-8', data: xml, success: function(xml) { // }, error: function(jqXHR, textStatus, errorThrown) { // } }); Why do I get different encodings and how do I get rid of this difference? I need to fix this problem because it's causing other on the server-side.

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  • Python list should be empty on class instance initialisation, but it's not. Why?

    - by canavanin
    Hi everyone! I would like to create instances of a class containing a list that's empty by default; instead of later setting this list to the final full list I would like to successively add items to it. Here's a piece of sample code illustrating this: #!/usr/bin/python class test: def __init__(self, lst=[], intg=0): self.lista = lst self.integer = intg name_dict = {} counter = 0 for name in ('Anne', 'Leo', 'Suzy'): counter += 1 name_dict[name] = test() name_dict[name].integer += 1 name_dict[name].lista.append(counter) print name, name_dict[name].integer, name_dict[name].lista When I ran the above program I expected to get Anne 1 [1] Leo 1 [2] Suzy 1 [3] as I assumed lista to always be initialised to an empty list. What I got instead was this: Anne 1 [1] Leo 1 [1, 2] Suzy 1 [1, 2, 3] If I replace self.lista = lst by self.lista = [] it works fine, just like when I add the line name_dict[name].lista = [] to the for loop. Why is it that the contents of the previous objects' lists are retained, yet their values of integer aren't? I am rather new to Python, so it would be great if someone could point out to me where my thoughts/assumptions have gone astray. Thanks a lot in advance for your replies.

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  • PostgreSQL storing paths for reference in scripts

    - by Brian D.
    I'm trying to find the appropriate place to store a system path in PostgreSQL. What I'm trying to do is load values into a table using the COPY command. However, since I will be referring to the same file path regularly I want to store that path in one place. I've tried creating a function to return the appropriate path, but I get a syntax error when I call the function in the COPY command. I'm not sure if this is the right way to go about it, but I'll post my code anyway. COPY command: COPY employee_scheduler.countries (code, name) FROM get_csv_path('countries.csv') WITH CSV; Function Definition: CREATE OR REPLACE FUNCTION employee_scheduler.get_csv_path(IN file_name VARCHAR(50)) RETURNS VARCHAR(250) AS $$ DECLARE path VARCHAR(200) := E'C:\\Brian\\Work\\employee_scheduler\\database\\csv\\'; file_path VARCHAR(250) := ''; BEGIN file_path := path || file_name; RETURN file_path; END; $$ LANGUAGE plpgsql; If anyone has a different idea on how to accomplish this I'm open to suggestions. Thanks for any help!

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  • Can I do this?? Trying to load an object from within itself.

    - by Smikey
    Hi all! I have an object which conforms to the NSCoding protocol. The object contains a method to save itself to memory, like so: - (void)saveToFile { NSMutableData *data = [[NSMutableData alloc] init]; NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data]; [archiver encodeObject:self forKey:kDataKey]; [archiver finishEncoding]; [data writeToFile:[self dataFilePath] atomically:YES]; [archiver release]; [data release]; } This works just fine. But I would also like to initialise an empty version of this object and then call its own 'Load' method to load whatever data exists on file into its variables. So I've created the following: - (void)loadFromFile { NSString *filePath = [self dataFilePath]; if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) { NSData *data = [[NSMutableData alloc] initWithContentsOfFile:[self dataFilePath]]; NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data]; self = [unarchiver decodeObjectForKey:kDataKey]; [unarchiver finishDecoding]; } } Now this second method doesn't manage to load any variables. Is this line not possible perhaps? self = [unarchiver decodeObjectForKey:kDataKey]; Ultimately I would like to use the code like this: One viewController takes user entered input, creates an object and saves it to memory using [anObject saveToFile]; And a second viewController creates an empty object, then initialises its values to those stored on file by calling: [emptyObject loadFromFile]; Any suggestions on how to make this work would be hugely appreciated. Thanks :) Michael

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  • overwrite parameters passed by querystring

    - by opensas
    I have the following problem I have a web framework built with classic asp that saves the page state in hidden textboxes, and then issues a submit to itself. Before submitting, we have a javascript functions that saves the action in a hidden "action" input, and then performs the submit. The page loads the state from those hidden texts, reads the action issued, reads extra parameters, like the id of the record to edit, and then builds the page accordingly. I'd like to make a url link to automatically start the page with "edit" action on a "x" id. So I was thinking about building the following url, for example http://myapp/user?action=edit&id=23 the problem is that when the page auto-submits, que url string keeps the parameters. I'd like to achieve the following: when the user clicks on http://myapp/user?action=edit&id=23 my page should receive the posted values action=edit and id=23 but the url should be just http://myapp/user and both parameters should be kept in the hidden texts... (I wonder if I make myself clear...) thanks a lot saludos sas ps: I have a couple of ideas about how to solve it, but I'll post them as answers...

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  • loop html table using jquery and for loop (not for each)

    - by Mandeep Singh
    I have a HTML table <table id="mytab"> <thead> <th>col1</th> <th>col2</th> </thead> <tbody> <tr> <td>1</td> <td>2</td> </tr> <tr> <td>11</td> <td>22</td> </tbody> </table> and i am writing the jquery function function LoopTable() { $row = $('#mytab tbody >tr"); //here I have successfully find all the rows. //now i want to loop on rows and find each column row for (var i=0; i<$rows.length; i++) { //need something here to find col data } what I should use to have column values from row

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  • How do I add array indices to the XML produced by JAXB?

    - by oconnor0
    I have a Java bean ala @XmlRootElement public class Bean { @XmlElementWrapper(name = "ints") @XmlElement(name = "int") int[] values; // constructors, getters, setters, etc... } JAXB is producing XML like <bean> <ints> <int>12</int> <int>34</int> <int>56</int> </ints> </bean> I would like the array indices to be included on the <int> tags as array position conveys important value. Preferably as attributes like <bean> <ints> <int id='0'>12</int> <int id='1'>34</int> <int id='2'>56</int> </ints> </bean> Is there a way to do this?

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  • Toggle image based on cookie value

    - by danit
    Im using a couple of JS functions to set a cookie named 'visible' with the value of either yes or no. Essentially Im using these values to decide if a <div> is visible or hidden. I've only just added the cookie, previously I had been using two images 1. Show 2. Hide as a button to hide and show the <div> like this: HTML: <img class="show" title="Show" alt="Show" src="images/show.png" /> <img class="hide" title="Hide" alt="Hide" src="images/hide.png" /> JQUERY: $("#tool").click(function() { $(".help").slideToggle(); $("#wrapper").animate({ opacity: 1.0 },200).slideToggle(200, function() { $("#tool img").toggle(); }); }); However I have now added the Cookie into the mix: $("#tool").click(function() { if(get_cookie('visible')== null) { set_cookie('visible','no'); } else { delete_cookie('visible'); } $(".help").slideToggle(); $("#wrapper").animate({ opacity: 1.0 },200).slideToggle(200, function() { $("#slider img").toggle(); }); }); So the .toggle() no longer matches the state of the <div> When the cookie value = no the show.png should be visible When the cookie value = yes then the hide.png should be visible Can anyone suggest how i can ammend this?

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  • Select rows from table1 and all the children from table2 into an object

    - by Patrick
    I want to pull data from table "Province_Notifiers" and also fetch all corresponding items from table "Province_Notifier_Datas". The table "Province_Notifier" has a guid to identify it (PK), table "Province_Notifier_Datas" has a column called BelongsToProvinceID witch is a foreign key to the "Province_Notifier" tables guid. I tried something like this: var records = from data in ctx.Province_Notifiers where DateTime.Now >= data.SendTime && data.Sent == false join data2 in ctx.Province_Notifier_Datas on data.Province_ID equals data2.BelongsToProvince_ID select new Province_Notifier { Email = data.Email, Province_ID = data.Province_ID, ProvinceName = data.ProvinceName, Sent = data.Sent, UserName = data.UserName, User_ID = data.User_ID, Province_Notifier_Datas = (new List<Province_Notifier_Data>().AddRange(data2)) }; This line is not working and i am trying to figure out how topull the data from table2 into that Province_Notifier_Datas variable. Province_Notifier_Datas = (new List<Province_Notifier_Data>().AddRange(data2)) I can add a record easily by adding the second table row into the Province_Notifier_Datas but i can't fetch it back. Province_Notifier dbNotifier = new Province_Notifier(); // set some values for dbNotifier dbNotifier.Province_Notifier_Datas.Add( new Province_Notifier_Data { BelongsToProvince_ID = userInput.Value.ProvinceId, EventText = GenerateNotificationDetail(notifierDetail) }); This works and inserts the data correctly into both tables. Edit: These error messages is thrown: Cannot convert from 'Province_Notifier_Data' to 'System.Collections.Generic.IEnumerable' If i look in Visual Studio, the variable "Province_Notifier_Datas" is of type System.Data.Linq.EntitySet The best overloaded method match for 'System.Collections.Generic.List.AddRange(System.Collections.Generic.IEnumerable)' has some invalid arguments Edit: var records = from data in ctx.Province_Notifiers where DateTime.Now >= data.SendTime && data.Sent == false join data2 in ctx.Province_Notifier_Datas on data.Province_ID equals data2.BelongsToProvince_ID into data2list select new Province_Notifier { Email = data.Email, Province_ID = data.Province_ID, ProvinceName = data.ProvinceName, Sent = data.Sent, UserName = data.UserName, User_ID = data.User_ID, Province_Notifier_Datas = new EntitySet<Province_Notifier_Data>().AddRange(data2List) }; Error 3 The name 'data2List' does not exist in the current context.

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  • Basic FreeMat/MATLAB syntax - dimension error

    - by 0x90
    I am using FreeMat, and I have an RGB picture which is a 3D matrix contains the columns and rows of the pictures and the RGB values for each pixel. Since there is not an intrinsic function to convert RGB picture to YIQ, I have implement one. I came up with this code: Assume I have a 3D array, image_rgb: matrix = [0.299 0.587 0.114; 0.596 -0.274 -0.322; 0.211 -0.523 0.312]; row = 1:length(image_rgb(:,1,1)); col = 1:length(image_rgb(1,:,1)); p = image_rgb(row,col,:); %Here I have the problem mage_yiq(row,col,:) = matrix*image_rgb(row,col,:); max_y = max (max(image_yiq(:,:,1))); max_i = max (max(image_yiq(:,:,2))); max_q = max (max(image_yiq(:,:,3))); %Renormalize the image again after the multipication % to [0,1]. image_yiq(:,:,1) = image_yiq(:,:,1)/max_y; image_yiq(:,:,2) = image_yiq(:,:,2)/max_i; image_yiq(:,:,3) = image_yiq(:,:,3)/max_q; I can't understand why the matrix multiplication fails. I want the code to be nice and not just to, multiply the matrix by hand...

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  • Problems with variadic function

    - by morpheous
    I have the following function from some legacy code that I am maintaining. long getMaxStart(long start, long count, const myStruct *s1, ...) { long i1, maxstart; myStruct *s2; va_list marker; maxstart = start; /*BUGFIX: 003 */ /*(va_start(marker, count);*/ va_start(marker, s1); for (i1 = 1; i1 <= count; i1++) { s2 = va_arg(marker, myStruct *); /* <- s2 is assigned null here */ maxstart = MAX(maxstart, s2->firstvalid); /* <- SEGV here */ } va_end(marker); return (maxstart); } When the function is called with only one myStruct argument, it causes a SEGV. The code compiled and run without crashing on Windows XP when I compiled it using VS2005. I have now moved the code to Ubuntu Karmic and I am having problems with the stricter compiler on Linux. Is anyone able to spot what is causing the parameter not to be read correctly in the var_arg() statement? I am compiling using gcc version 4.4.1 Edit The statement that causes the SEGV is this one: start = getMaxStart(start, 1, ms1); The variables 'start' and 'ms1' have valid values when the code execution first reaches this line.

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  • How to fetch particular element from string after splitting it, using XSLT split() ?

    - by Vijay
    Hi All, I have one query regarding XSLT functions. I am using split function to fetch values from a string. I am using separator as "*". e.g. String : {"item1*item2*item3*item4"} split function I am using is as; <xsl:template name="SplitItemsCollection"> <xsl:param name="list" select="''"/> <xsl:param name="separator" select="'*'"/> <xsl:if test="not($list = '' or $separator = '')"> <xsl:variable name="head" select="substring-before(concat($list, $separator), $separator)"/> <xsl:variable name="tail" select="substring-after($list, $separator)"/> <xsl:value-of select="$head"/> <xsl:call-template name="split"> <xsl:with-param name="list" select="$tail"/> <xsl:with-param name="separator" select="$separator"/> </xsl:call-template> </xsl:if> </xsl:template> This function returns me all the items. Is there any way to fetch particular item from these separated items ? Say I want to fetch item3. Can we do it directly ? Thanks in advance.

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  • Input questions mysql php html

    - by Marcelo
    (Q1)Hi I'm using textbox in my project and I can't receive the values that are typed <textarea rows="5" cols="60"> Type your suggestion </textarea> <br> <input type="submit" name="sugestao" value="Submit" /> Sorry I don't know how to 'kill' html code, that's why < is missing. All I'm getting in the column of the database from this text box is "Submit", I'd like to receive whatever is written in the text area. How can I make the value equal whaterever is typed? (Q2) How can I make sure that I'll only store the same type(int,varchar,text) that I setted,declared in the database. For example: age(int), but if someone types "abc" in the input it will be stored in my database as the value 0 . How can I forbid this, and only save the age when it's just int and all the other fields(like name, email) are filled ?. And if is still possible warn the user that he is typing something wrong, don't need to say where. Sorry for any mistake in English and Thanks for the attention.

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  • Export sheet from Excel to CSV

    - by Mike Wills
    I am creating a spread sheet to help ease the entry of data into one of our systems. They are entering inventory items into this spread sheet to calculate the unit cost of the item (item cost + tax + S&H). The software we purchased cannot do this. Aan invoice can have one or more lines (duh!) and I calculate the final unit cost. This is working fine. I then want to take that data and create a CSV from that so they can load it into our inventory system. I currently have a second tab that is laid out like I want the CSV, and I do an equal cell (=Sheet!A3) to get the values on the "export sheet". The problem is when they save this to a CSV, there are many blank lines that need to be deleted before they can upload it. I want a file that only contains the data that is needed. I am sure this could be done in VBA, but I don't know where to start or know how to search for an example to start. Any direction or other options would be appreciated.

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  • Algorithm for generating an array of non-equal costs for a transport problem optimization

    - by Carlos
    I have an optimizer that solves a transportation problem, using a cost matrix of all the possible paths. The optimiser works fine, but if two of the costs are equal, the solution contains one more path that the minimum number of paths. (Think of it as load balancing routers; if two routes are same cost, you'll use them both.) I would like the minimum number of routes, and to do that I need a cost matrix that doesn't have two costs that are equal within a certain tolerance. At the moment, I'm passing the cost matrix through a baking function which tests every entry for equality to each of the other entries, and moves it a fixed percentage if it matches. However, this approach seems to require N^2 comparisons, and if the starting values are all the same, the last cost will be r^N bigger. (r is the arbitrary fixed percentage). Also there is the problem that by multiplying by the percentage, you end up on top of another value. So the problem seems to have an element of recursion, or at least repeated checking, which bloats the code. The current implementation is basically not very good (I won't paste my GOTO-using code here for you all to mock), and I'd like to improve it. Is there a name for what I'm after, and is there a standard implementation? Example: {1,1,2,3,4,5} (tol = 0.05) becomes {1,1.05,2,3,4,5}

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  • Html.RadioButton group defaulting to 0

    - by awrigley
    Hi A default value of 0 is creeping into a Surveys app I am developing, for no reason that I can see. The problem is as follows: I have a group of Html.RadioButtons that represent the possible values a user can choose to answer a survey question (1 == Not at all, 2 == A little, 3 == A lot). I have used a tinyint datatype, that does not allow null, to store the answer to each question. The view code looks like this: <ol class="SurveyQuestions"> <% foreach (SurveyQuestion question in Model.Questions) { string col = question.QuestionColumn; %> <li><%=question.QuestionText%> <ul style="float:right;" class="MultiChoice"> <li><%= Html.RadioButton(col, "1")%></li> <li><%= Html.RadioButton(col, "2")%></li> <li><%= Html.RadioButton(col, "3")%></li> </ul> <%= Html.ValidationMessage(col, "*") %> </li> <% } %> </ol> [Note on the above code:] Each survey has about 70 questions, so I have put the questions text in one table, and store the results in a different table. I have put the Questions into my form view model (hence Model.Questions); the questions table has a field called QuestionColumn that allows me to link up the answer table column to the question, as shown above (<%= Html.RadioButton(col, "1")%, etc) [/Note] However, when the user DOESN'T answer the question, the value 0 is getting inserted into the database column. As a result, I don't get what I expect, ie, a validation error. In no place have I stipulated a default value of 0 for the fields in the answers table. So what is happening? Any ideas?

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  • Combining Java hashcodes into a "master" hashcode

    - by Nick Wiggill
    I have a vector class with hashCode() implemented. It wasn't written by me, but uses 2 prime numbers by which to multiply the 2 vector components before XORing them. Here it is: /*class Vector2f*/ ... public int hashCode() { return 997 * ((int)x) ^ 991 * ((int)y); //large primes! } ...As this is from an established Java library, I know that it works just fine. Then I have a Boundary class, which holds 2 vectors, "start" and "end" (representing the endpoints of a line). The values of these 2 vectors are what characterize the boundary. /*class Boundary*/ ... public int hashCode() { return 1013 * (start.hashCode()) ^ 1009 * (end.hashCode()); } Here I have attempted to create a good hashCode() for the unique 2-tuple of vectors (start & end) constituting this boundary. My question: Is this hashCode() implementation going to work? (Note that I have used 2 different prime numbers in the latter hashCode() implementation; I don't know if this is necessary but better to be safe than sorry when trying to avoid common factors, I guess -- since I presume this is why primes are popular for hashing functions.)

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  • Memory management of objects returned by methods (iOS / Objective-C)

    - by iOSNewb
    I am learning Objective-C and iOS programming through the terrific iTunesU course posted by Stanford (http://www.stanford.edu/class/cs193p/cgi-bin/drupal/) Assignment 2 is to create a calculator with variable buttons. The chain of commands (e.g. 3+x-y) is stored in a NSMutableArray as "anExpression", and then we sub in random values for x and y based on an NSDictionary to get a solution. This part of the assignment is tripping me up: The final two [methods] “convert” anExpression to/from a property list: + (id)propertyListForExpression:(id)anExpression; + (id)expressionForPropertyList:(id)propertyList; You’ll remember from lecture that a property list is just any combination of NSArray, NSDictionary, NSString, NSNumber, etc., so why do we even need this method since anExpression is already a property list? (Since the expressions we build are NSMutableArrays that contain only NSString and NSNumber objects, they are, indeed, already property lists.) Well, because the caller of our API has no idea that anExpression is a property list. That’s an internal implementation detail we have chosen not to expose to callers. Even so, you may think, the implementation of these two methods is easy because anExpression is already a property list so we can just return the argument right back, right? Well, yes and no. The memory management on this one is a bit tricky. We’ll leave it up to you to figure out. Give it your best shot. Obviously, I am missing something with respect to memory management because I don't see why I can't just return the passed arguments right back. Thanks in advance for any answers!

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  • Strongly typed dynamic Linq sorting

    - by David
    I'm trying to build some code for dynamically sorting a Linq IQueryable<. The obvious way is here, which sorts a list using a string for the field name http://dvanderboom.wordpress.com/2008/12/19/dynamically-composing-linq-orderby-clauses/ However I want one change - compile time checking of field names, and the ability to use refactoring/Find All References to support later maintenance. That means I want to define the fields as f=f.Name, instead of as strings. For my specific use I want to encapsulate some code that would decide which of a list of named "OrderBy" expressions should be used based on user input, without writing different code every time. Here is the gist of what I've written: var list = from m Movies select m; // Get our list var sorter = list.GetSorter(...); // Pass in some global user settings object sorter.AddSort("NAME", m=m.Name); sorter.AddSort("YEAR", m=m.Year).ThenBy(m=m.Year); list = sorter.GetSortedList(); ... public class Sorter ... public static Sorter GetSorter(this IQueryable source, ...) The GetSortedList function determines which of the named sorts to use, which results in a List object, where each FieldData contains the MethodInfo and Type values of the fields passed in AddSort: public SorterItem AddSort(Func field) { MethodInfo ... = field.Method; Type ... = TypeOf(TKey); // Create item, add item to diction, add fields to item's List // The item has the ThenBy method, which just adds another field to the List } I'm not sure if there is a way to store the entire field object in a way that would allow it be returned later (it would be impossible to cast, since it is a generic type) Is there a way I could adapt the sample code, or come up with entirely new code, in order to sort using strongly typed field names after they have been stored in some container and retrieved (losing any generic type casting)

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  • Best Functional Approach

    - by dbyrne
    I have some mutable scala code that I am trying to rewrite in a more functional style. It is a fairly intricate piece of code, so I am trying to refactor it in pieces. My first thought was this: def iterate(count:Int,d:MyComplexType) = { //Generate next value n //Process n causing some side effects return iterate(count - 1, n) } This didn't seem functional at all to me, since I still have side effects mixed throughout my code. My second thought was this: def generateStream(d:MyComplexType):Stream[MyComplexType] = { //Generate next value n return Stream.cons(n, generateStream(n)) } for (n <- generateStream(initialValue).take(2000000)) { //process n causing some side effects } This seemed like a better solution to me, because at least I've isolated my functional value-generation code from the mutable value-processing code. However, this is much less memory efficient because I am generating a large list that I don't really need to store. This leaves me with 3 choices: Write a tail-recursive function, bite the bullet and refactor the value-processing code Use a lazy list. This is not a memory sensitive app (although it is performance sensitive) Come up with a new approach. I guess what I really want is a lazily evaluated sequence where I can discard the values after I've processed them. Any suggestions?

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