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  • Vector iterators in for loops, return statements, warning, c++

    - by Crystal
    Had 3 questions regarding a hw assignment for C++. The goal was to create a simple palindrome method. Here is my template for that: #ifndef PALINDROME_H #define PALINDROME_H #include <vector> #include <iostream> #include <cmath> template <class T> static bool palindrome(const std::vector<T> &input) { std::vector<T>::const_iterator it = input.begin(); std::vector<T>::const_reverse_iterator rit = input.rbegin(); for (int i = 0; i < input.size()/2; i++, it++, rit++) { if (!(*it == *rit)) { return false; } } return true; } template <class T> static void showVector(const std::vector<T> &input) { for (std::vector<T>::const_iterator it = input.begin(); it != input.end(); it++) { std::cout << *it << " "; } } #endif Regarding the above code, can you have more than one iterator declared in the first part of the for loop? I tried defining both the "it" and "rit" in the palindrome() method, and I kept on getting an error about needing a "," before rit. But when I cut and paste outside the for loop, no errors from the compiler. (I'm using VS 2008). Second question, I pretty much just brain farted on this one. But is the way I have my return statements in the palindrome() method ok? In my head, I think it works like, once the *it and *rit do not equal each other, then the function returns false, and the method exits at this point. Otherwise if it goes all the way through the for loop, then it returns true at the end. I totally brain farted on how return statements work in if blocks and I tried looking up a good example in my book and I couldn't find one. Finally, I get this warnings: \palindrome.h(14) : warning C4018: '<' : signed/unsigned mismatch Now is that because I run my for loop until (i < input.size()/2) and the compiler is telling me that input can be negative? Thanks!

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  • NHibernate Empty Set Clauses in SQL Update Statements

    - by Brian Wilkinson
    I'm getting SQL update statements from NHibernate having a empty set clause ie UPDATE SET WHERE x == ? This propblem is occuring when a child entity is being updated for some reason the sql statement is being run against the Parent Entity, for some reason NHibenate is saying the parent has changed but when the set clause is being built no changes are found, can anyone help. The application I am constructing isn 3 tier. The domain entities are light weight data contract only entities.

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  • Python style: if statements vs. boolean evaluation

    - by mkscrg
    One of the ideas of Python's design philosophy is "There should be one ... obvious way to do it." (PEP 20), but that can't always be true. I'm specifically referring to (simple) if statements versus boolean evaluation. Consider the following: if words: self.words = words else: self.words = {} versus self.words = words or {} With such a simple situation, which is preferable, stylistically speaking? With more complicated situations one would choose the if statement for readability, right?

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  • SQL Server, View using multiple select statements

    - by phil
    I've banging my head for hours, it seems simple enough, but here goes: I'd like to create a view using multiple select statements that outputs a Single record-set Example: CREATE VIEW dbo.TestDB AS SELECT X AS 'First' FROM The_Table WHERE The_Value = 'y' SELECT X AS 'Second' FROM The_Table WHERE The_Value = 'z' i wanted to output the following recordset: Column_1 | Column_2 'First' 'Second' any help would be greatly appreciated! -Thanks.

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  • What is the difference between these two statements (asp.net/c#/entity framework)

    - by user318573
    IEnumerable<Department> myQuery = (from D in myContext.Departments orderby D.DeptName select D); var myQuery = (from D in myContext.Departments orderby D.DeptName select D); What is the difference between these two statements above? In my little asp.net/C#/ EF4.0 app I can write them either way, and as far as how I want to use them, they both work, but there has to be a reason why I would choose one over the other?

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  • Quickbooks 2009 2010

    - by Bronwyn
    I have configured my bank account within quickbooks to import bank statements. I have wxported the bank statement. Then used the convert process available within QB to convert. The file name shows the bsb then some other figures and then the account number. However it will not import. I am wondering how ot make this work. Can I change the file name to match my QB account details and thus enable the importing. This is a technical question. Many thanks Bronwyn

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  • conditional selects with jQuery and the Validation plugin

    - by dbonomo
    Hi, I've got a form that I am validating with the jQuery validation plugin. I would like to add a conditional select box (a selection box that is populated/shown depending on the selection of another) and have it validate as well. Here is what I have so far: $(document).ready(function(){ $("#customer_information").validate({ //disable the submit button after it is clicked to prevent multiple submissions submitHandler: function(form){ if(!this.wasSent){ this.wasSent = true; $(':submit', form).val('Please wait...') .attr('disabled', 'disabled') .addClass('disabled'); form.submit(); } else { return false; } }, //Customizes error placement errorPlacement: function(error, element) { error.insertAfter(element) error.wrap("<div class=\"form_error\">") } }); $(".courses").hide(); $("#course_select").change(function() { switch($(this).val()){ case "Certificates": $(".courses").hide().parent().find("#Certificates").show(); $(".filler").hide(); break; case "Associates": $(".courses").hide().parent().find("#Associates").show(); $(".filler").hide(); break; case "": $(".filler").show(); $(".courses").hide(); } }); }); And the HTML: <select id="course_select"> <option value="">Please Select</option> <option value="Certificates">Certificates</option> <option value="Associates">Associates</option> </select> <div id="Form0" class="filler"><select name="filler_select"><option value="">Please Select Course Type</option></select></div> <div id="Associates" class="courses"> <select name="lead_source_id" id="Requested Program" class="required"> <option value="">Please Select</option> <option value="01">Health Information Technology</option> <option value="02">Human Resources </option> <option value="03">Marketing </option> </select> </div> <div id="Certificates" class="courses"> <select name="lead_source_id" id="Requested Program" class="required"> <option value="">Please Select</option> <option value="04">Accounting Services</option> <option value="05">Bookkeeping</option> <option value="06">Child Day Care</option> </select> </div> So far, the select is working for me, but validation thinks that the field is empty even when a value is selected. It looks like there are a ton of ways to do conditional selects in jQuery. This was the best way I managed to work out (I'm new to jQuery), but I'd love to hear what you folks feel is the "best" way, especially if it works well with the validation plugin. Thanks!

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  • Investigation: Can different combinations of components effect Dataflow performance?

    - by jamiet
    Introduction The Dataflow task is one of the core components (if not the core component) of SQL Server Integration Services (SSIS) and often the most misunderstood. This is not surprising, its an incredibly complicated beast and we’re abstracted away from that complexity via some boxes that go yellow red or green and that have some lines drawn between them. Example dataflow In this blog post I intend to look under that facade and get into some of the nuts and bolts of the Dataflow Task by investigating how the decisions we make when building our packages can affect performance. I will do this by comparing the performance of three dataflows that all have the same input, all produce the same output, but which all operate slightly differently by way of having different transformation components. I also want to use this blog post to challenge a common held opinion that I see perpetuated over and over again on the SSIS forum. That is, that people assume adding components to a dataflow will be detrimental to overall performance. Its not surprising that people think this –it is intuitive to think that more components means more work- however this is not a view that I share. I have always been of the opinion that there are many factors affecting dataflow duration and the number of components is actually one of the less important ones; having said that I have never proven that assertion and that is one reason for this investigation. I have actually seen evidence that some people think dataflow duration is simply a function of number of rows and number of components. I’ll happily call that one out as a myth even without any investigation!  The Setup I have a 2GB datafile which is a list of 4731904 (~4.7million) customer records with various attributes against them and it contains 2 columns that I am going to use for categorisation: [YearlyIncome] [BirthDate] The data file is a SSIS raw format file which I chose to use because it is the quickest way of getting data into a dataflow and given that I am testing the transformations, not the source or destination adapters, I want to minimise external influences as much as possible. In the test I will split the customers according to month of birth (12 of those) and whether or not their yearly income is above or below 50000 (2 of those); in other words I will be splitting them into 24 discrete categories and in order to do it I shall be using different combinations of SSIS’ Conditional Split and Derived Column transformation components. The 24 datapaths that occur will each input to a rowcount component, again because this is the least resource intensive means of terminating a datapath. The test is being carried out on a Dell XPS Studio laptop with a quad core (8 logical Procs) Intel Core i7 at 1.73GHz and Samsung SSD hard drive. Its running SQL Server 2008 R2 on Windows 7. The Variables Here are the three combinations of components that I am going to test:     One Conditional Split - A single Conditional Split component CSPL Split by Month of Birth and income category that will use expressions on [YearlyIncome] & [BirthDate] to send each row to one of 24 outputs. This next screenshot displays the expression logic in use: Derived Column & Conditional Split - A Derived Column component DER Income Category that adds a new column [IncomeCategory] which will contain one of two possible text values {“LessThan50000”,”GreaterThan50000”} and uses [YearlyIncome] to determine which value each row should get. A Conditional Split component CSPL Split by Month of Birth and Income Category then uses that new column in conjunction with [BirthDate] to determine which of the same 24 outputs to send each row to. Put more simply, I am separating the Conditional Split of #1 into a Derived Column and a Conditional Split. The next screenshots display the expression logic in use: DER Income Category         CSPL Split by Month of Birth and Income Category       Three Conditional Splits - A Conditional Split component that produces two outputs based on [YearlyIncome], one for each Income Category. Each of those outputs will go to a further Conditional Split that splits the input into 12 outputs, one for each month of birth (identical logic in each). In this case then I am separating the single Conditional Split of #1 into three Conditional Split components. The next screenshots display the expression logic in use: CSPL Split by Income Category         CSPL Split by Month of Birth 1& 2       Each of these combinations will provide an input to one of the 24 rowcount components, just the same as before. For illustration here is a screenshot of the dataflow containing three Conditional Split components: As you can these dataflows have a fair bit of work to do and remember that they’re doing that work for 4.7million rows. I will execute each dataflow 10 times and use the average for comparison. I foresee three possible outcomes: The dataflow containing just one Conditional Split (i.e. #1) will be quicker There is no significant difference between any of them One of the two dataflows containing multiple transformation components will be quicker Regardless of which of those outcomes come to pass we will have learnt something and that makes this an interesting test to carry out. Note that I will be executing the dataflows using dtexec.exe rather than hitting F5 within BIDS. The Results and Analysis The table below shows all of the executions, 10 for each dataflow. It also shows the average for each along with a standard deviation. All durations are in seconds. I’m pasting a screenshot because I frankly can’t be bothered with the faffing about needed to make a presentable HTML table. It is plain to see from the average that the dataflow containing three conditional splits is significantly faster, the other two taking 43% and 52% longer respectively. This seems strange though, right? Why does the dataflow containing the most components outperform the other two by such a big margin? The answer is actually quite logical when you put some thought into it and I’ll explain that below. Before progressing, a side note. The standard deviation for the “Three Conditional Splits” dataflow is orders of magnitude smaller – indicating that performance for this dataflow can be predicted with much greater confidence too. The Explanation I refer you to the screenshot above that shows how CSPL Split by Month of Birth and salary category in the first dataflow is setup. Observe that there is a case for each combination of Month Of Date and Income Category – 24 in total. These expressions get evaluated in the order that they appear and hence if we assume that Month of Date and Income Category are uniformly distributed in the dataset we can deduce that the expected number of expression evaluations for each row is 12.5 i.e. 1 (the minimum) + 24 (the maximum) divided by 2 = 12.5. Now take a look at the screenshots for the second dataflow. We are doing one expression evaluation in DER Income Category and we have the same 24 cases in CSPL Split by Month of Birth and Income Category as we had before, only the expression differs slightly. In this case then we have 1 + 12.5 = 13.5 expected evaluations for each row – that would account for the slightly longer average execution time for this dataflow. Now onto the third dataflow, the quick one. CSPL Split by Income Category does a maximum of 2 expression evaluations thus the expected number of evaluations per row is 1.5. CSPL Split by Month of Birth 1 & CSPL Split by Month of Birth 2 both have less work to do than the previous Conditional Split components because they only have 12 cases to test for thus the expected number of expression evaluations is 6.5 There are two of them so total expected number of expression evaluations for this dataflow is 6.5 + 6.5 + 1.5 = 14.5. 14.5 is still more than 12.5 & 13.5 though so why is the third dataflow so much quicker? Simple, the conditional expressions in the first two dataflows have two boolean predicates to evaluate – one for Income Category and one for Month of Birth; the expressions in the Conditional Split in the third dataflow however only have one predicate thus they are doing a lot less work. To sum up, the difference in execution times can be attributed to the difference between: MONTH(BirthDate) == 1 && YearlyIncome <= 50000 and MONTH(BirthDate) == 1 In the first two dataflows YearlyIncome <= 50000 gets evaluated an average of 12.5 times for every row whereas in the third dataflow it is evaluated once and once only. Multiply those 11.5 extra operations by 4.7million rows and you get a significant amount of extra CPU cycles – that’s where our duration difference comes from. The Wrap-up The obvious point here is that adding new components to a dataflow isn’t necessarily going to make it go any slower, moreover you may be able to achieve significant improvements by splitting logic over multiple components rather than one. Performance tuning is all about reducing the amount of work that needs to be done and that doesn’t necessarily mean use less components, indeed sometimes you may be able to reduce workload in ways that aren’t immediately obvious as I think I have proven here. Of course there are many variables in play here and your mileage will most definitely vary. I encourage you to download the package and see if you get similar results – let me know in the comments. The package contains all three dataflows plus a fourth dataflow that will create the 2GB raw file for you (you will also need the [AdventureWorksDW2008] sample database from which to source the data); simply disable all dataflows except the one you want to test before executing the package and remember, execute using dtexec, not within BIDS. If you want to explore dataflow performance tuning in more detail then here are some links you might want to check out: Inequality joins, Asynchronous transformations and Lookups Destination Adapter Comparison Don’t turn the dataflow into a cursor SSIS Dataflow – Designing for performance (webinar) Any comments? Let me know! @Jamiet

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  • C# Conditional Compilation and framework targets

    - by McKAMEY
    There are a few minor places where code for my project may be able to be drastically improved if the target framework were a newer version. I'd like to be able to better leverage conditional compilation in C# to switch these as needed. Something like: #if NET_40 using FooXX = Foo40; #elif NET_35 using FooXX = Foo35; #else using FooXX = Foo20; #endif Do these symbols come for free? Do I need to inject these symbols as part of the project configuration? Seems easy enough to do since I'll know which framework is being targeted from msbuild. I think I've seen that NET_40 symbol isn't defined? If so I think I could do this? #if !NET_35 && !NET_20 #define NET_40 #endif Or do I need to define it in the msbuild command: /p:DefineConstants="NET_40"

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  • pass value from embedded function into conditional of page the embedded function is included on

    - by Brad
    I have a page that includes/embeds a file that contains a number of functions. One of the functions has a variable I want to pass back onto the page that the file is embedded on. <?php include('functions.php'); userInGroup(); if($user_in_group) { print 'user is in group'; } else { print 'user is not in group'; } ?> function within functions.php <?php function userInGroup() { foreach($group_access as $i => $group) { if($group_session == $group) { $user_in_group = TRUE; break; } else { $user_in_group == FALSE; } } }?> I am unsure as to how I can pass the value from the function userInGroup back to the page it runs the conditional if($user_in_group) on Any help is appreciated.

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  • Missing Java error on conditional expression?

    - by Federico Cristina
    With methods test1() and test2(), I get a Type Mismatch Error: Cannot convert from null to int, which is correct; but why am I not getting the same in method test3()? How does Java evaluates the conditional expression differently in that case? (obviusly, a NullPointerException will rise in runtime). Is it a missing error? public class Test { public int test1(int param) { return null; } public int test2(int param) { if (param > 0) return param; return null; } public int test3(int param) { return (param > 0 ? return param : return null); } } Thanks in advance!

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  • Objective-C "if" statements not retaining

    - by seanny94
    I know the title of this question is a bit confusing, but here it goes anyway: I'm creating an NSString after an if statement but it just doesn't seem to want to retain outside of the statement. My conditional looks like this: if ([[password stringValue] isEqualToString:@""]) { NSString *pwd = [[NSString alloc]initWithString:@"password"]; } else { NSString *pwd = [[NSString alloc]initWithFormat:@"%@", [password stringValue]]; } ... and I call pwd later in the script like this: NSArray *arguments; arguments = [NSArray arrayWithObjects: ip, pwd, nil]; [task setArguments: arguments]; But when I do so in this way, the first snippet returns a warning of Unused variable 'pwd' and the latter call ends up in an error of 'pwd' undeclared. What am I doing wrong here? Thanks in advance. ;)

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  • PDO update query with conditional?

    - by dmontain
    I have a PDO mysql that updates 3 fields. $update = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2, field3=:field3 WHERE key=:key"); But I want field3 to be updated only when $update3 = true; (meaning that the update of field3 is controlled by a conditional statement) Is this possible to accomplish with a single query? I could do it with 2 queries where I update field1 and field2 then check the boolean and update field3 if needed in a separate query. //run this query to update only fields 1 and 2 $update_part1 = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2 WHERE key=:key"); //if field3 should be update, run a separate query to update it separately if ($update3){ $update_part2 = $mypdo->prepare("UPDATE tablename SET field3=:field3 WHERE key=:key"); } But hopefully there is a way to accomplish this in 1 query?

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  • Update query with conditional?

    - by dmontain
    I'm not sure if this possible. If not, let me know. I have a PDO mysql that updates 3 fields. $update = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2, field3=:field3 WHERE key=:key"); But I want field3 to be updated only when $update3 = true; (meaning that the update of field3 is controlled by a conditional statement) Is this possible to accomplish with a single query? I could do it with 2 queries where I update field1 and field2 then check the boolean and update field3 if needed in a separate query. //run this query to update only fields 1 and 2 $update_part1 = $mypdo->prepare("UPDATE tablename SET field1=:field1, field2=:field2 WHERE key=:key"); //if field3 should be update, run a separate query to update it separately if ($update3){ $update_part2 = $mypdo->prepare("UPDATE tablename SET field3=:field3 WHERE key=:key"); } But hopefully there is a way to accomplish this in 1 query?

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  • Cell color change In Excel Using Conditional formatting in C#

    - by Suryakavitha
    Hi, I have exported datatable to excel successfully... Now i have to change some cell color using Conditional formatting in Excel sheet using C#.... For example if a cell contains text as "Cat" it should be display in Green color and if a cell contains text as "Dog" it should display in blue Color.... Now how can i do this ? Plz Anyone tell me the solution of this ... or give me the code for it... Thanks In Advance..

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  • USing Min/Max with conditional operator

    - by user638501
    Hello All, I am trying to run a query to find max and min values, and then use a conditional operator. however when I try to run the following query, it gives me error - "misuse of aggregate: min()". My query is: SELECT a.prim_id, min(b.new_len*36) as min_new_len, max(b.new_len*36) as max_new_len FROM tb_first a, tb_second b WHERE a.sec_id = b.sec_id AND min_new_len > 1900 AND max_new_len < 75000 GROUP BY a.prim_id ORDER BY avg(b.new_len*36); Any suggestions ?

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  • How can I support conditional validation of model properties

    - by Jeff
    I currently have a form that I am building that needs to support two different versions. Each version might use a different subset of form fields. I have to do this to support two different clients, but I don't want to have entirely different controller actions for both. So, I am trying to come up with a way to use a strongly typed model with validation attributes but have some of these attributes be conditional. Some approaches I can think of is similar to steve sanderson's partial validation approach. Where I would clear the model errors in a filter OnActionExecuting based on which version of the form was active. The other approach I was thinking of would to break the model up into pieces using something like class FormModel { public Form1 Form1Model {get; set;} public Form2 FormModel {get; set;} } and then we would validate appropriately depending on

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  • How to do conditional comments in drupal?

    - by wamp
    <!-- Additional IE/Win specific style sheet (Conditional Comments) --> <!--[if IE]> <style type="text/css" media="all">@import "files/tabs-ie.css";</style> <script type="text/javascript" src="files/DOMAssistantCompressed-2.7.4.js"></script> <script type="text/javascript" src="files/ie-css3.js"></script> <![endif]--> .. <!--[if IE 7.0]> <link rel="stylesheet" href="files/ie-7.css" type="text/css" media="all" charset="utf-8" /> <![endif]--> How to do the above in drupal?

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  • StructureMap 'conditional singleton' for Lucene.Net IndexReader

    - by Gareth D
    I have a threadsafe object that is expensive to create and needs to be available through my application (a Lucene.Net IndexReader). The object can become invalid, at which point I need to recreate it (IndexReader.IsCurrent is false, need a new instance using IndexReader.Reopen). I'd like to able to use an IoC container (StructureMap) to manage the creation of the object, but I can't work out if this scenario is possible. It feels like some kind of "conditional singleton" lifecycle. Does StructureMap provide such a feature? Any alternative suggestions?

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  • Conditional Required Attribute for validation

    - by jeriley
    We're trying to get a conditional attribute to work, case in point, there's a boolean (checkbox) that if checked, its related text is required. So, ideally we'd have something like ... public bool Provision { get; set; } [ConditionalRequirement(IsNeededWhenTrue = Provision)] public string ProvisionText { get; set; } Is this even possible? Alternate idea (not as elegant?) public bool Provision2 { get; set; } [PropertyRequired(RequiredBooleanPropertyName = "Provision2")] public string Provision2Text { get; set; } I'd hate to use the magic string method ... but any other ideas?

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  • Problem using Conditional Operation with Nullable Int

    - by Rajarshi
    A small problem. Any idea guys why this does not work? int? nullableIntVal = (this.Policy == null) ? null : 1; I am trying to return 'null' if the left hand expression is True, else 1. Seems simple but gives compilation error - Type of conditional expression cannot be determined because there is no implicit conversion between 'null' and 'int' If I replace the " ? null : 1 " with any valid int, then there is no problem.

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  • SQL Server 2008 - Conditional Query

    - by Villager
    Hello, SQL is not one of my strong suits. I have a SQL Server 2008 database. This database has a stored procedure that takes in eight int parameters. For the sake of keeping this question focused, I will use one of these parameters for reference: @isActive int Each of these int parameters will be -1, 0, or 1. -1 means "Unknown" or "Don't Care". Basically, I need to query a table such that if the int parameter is NOT -1, I need to consider it in my WHERE clause. Because there are eight int parameters, an IF-ELSE statement does not seem like a good idea. At the same time, I do not know how else to do this? Is there an elegant way in SQL to add a WHERE conditional if a parameter does NOT equal a value? Thank you!

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