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  • c++ Multiple Inheritance - Compiler modifying my pointers

    - by Bob
    If I run the following code, I get different addresses printed. Why? class Base1 { int x; }; class Base2 { int y; }; class Derived : public Base1, public Base2 { }; union U { Base2* b; Derived* d; U(Base2* b2) : b(b) {} }; int main() { Derived* d = new Derived; cout << d << "\n"; cout << U(d).d << "\n"; return 0; } Even more fun is if you repeatedly go in and out of the union the address keeps incrementing by 4, like this int main() { Derived* d = new Derived; cout << d << "\n"; d = U(d).d; cout << d << "\n"; d = U(d).d; cout << d << "\n"; return 0; } If the union is modified like this, then the problem goes away union U { void* v; Base2* b; Derived* d; U(void* v) : v(v) {} }; Also, if either base class is made empty, the problem goes away. Is this a compiler bug? I want it to leave my pointers the hell alone.

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  • In SQL, if we rename INNER JOIN as INTERSECT JOIN, LEFT OUTER JOIN as LEFT UNION JOIN, and FULL OUTE

    - by Jian Lin
    In SQL, the name Join gives an idea of "merging" or a sense of "union", making something bigger. But in fact, as in the other post http://stackoverflow.com/questions/2706051/in-sql-a-join-is-actually-an-intersection-and-it-is-also-a-linkage-or-a-sidew it turns out that a Join (Inner Join) is actually an Intersection. So if we think of Join = Inner Join = Intersect Join Left Outer Join = Left Union Join Full Outer Join = Full Union Join = Union Join then we always get a feel of what's happening, and maybe never forget what they are easily. In a way, we can think of Intersect as "making it less", therefore it is excluding something. That's why the name "Join" won't go with the idea of "Intersect". But in fact, both Intersect and Union can be thought of as: Union: bringing something together and merge them unconditionally. Intersect: bringing something together and merge them based on some condition. so the "bringing something together" is probably what "Join" is all about. It is like, Intersection is a "half glass of water" -- we can thinking of it as "excluding something" or as "bringing something together and accepting the common ones". So if the word "Intersect Join" is used, maybe a clear picture is there, and "Union Join" can be a clear picture too. Maybe the word "Inner Join" and "Outer Join" is very clear when we use SQL a lot. Somehow, the word "Outer" tends to give a feeling that it is "outside" and excluding something rather than a "Union".

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  • F# and statically checked union cases

    - by Johan Jonasson
    Soon me and my brother-in-arms Joel will release version 0.9 of Wing Beats. It's an internal DSL written in F#. With it you can generate XHTML. One of the sources of inspiration have been the XHTML.M module of the Ocsigen framework. I'm not used to the OCaml syntax, but I do understand XHTML.M somehow statically check if attributes and children of an element are of valid types. We have not been able to statically check the same thing in F#, and now I wonder if someone have any idea of how to do it? My first naive approach was to represent each element type in XHTML as a union case. But unfortunately you cannot statically restrict which cases are valid as parameter values, as in XHTML.M. Then I tried to use interfaces (each element type implements an interface for each valid parent) and type constraints, but I didn't manage to make it work without the use of explicit casting in a way that made the solution cumbersome to use. And it didn't feel like an elegant solution anyway. Today I've been looking at Code Contracts, but it seems to be incompatible with F# Interactive. When I hit alt + enter it freezes. Just to make my question clearer. Here is a super simple artificial example of the same problem: type Letter = | Vowel of string | Consonant of string let writeVowel = function | Vowel str -> sprintf "%s is a vowel" str I want writeVowel to only accept Vowels statically, and not as above, check it at runtime. How can we accomplish this? Does anyone have any idea? There must be a clever way of doing it. If not with union cases, maybe with interfaces? I've struggled with this, but am trapped in the box and can't think outside of it.

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  • SQL Aggregate all Purchases for a certain product with same rebatecode

    - by debuggerlikeanother
    Hi SO, i would like to aggregate all purchases for a certain product that used the same rebatecode (using SQL Server 2005) Assume we have the following table: ID ProductID Product RebateCode Amount 1 123 7HM ABC 1 2 123 7HM XYZ 2 3 124 7HM ABC 10 4 124 7HM XYZ 20 5 125 2EB LOI 4 6 126 2EB LOI 40 CREATE TABLE #ProductSales(ID SMALLINT, ProductID int, Product varchar(6), RebateCode varchar(4), Amount int) GO INSERT INTO #ProductSales select 1, 123, '7HM', 'A', 1 union all select 2, 123, '7HM', 'B', 2 union all select 3, 124, '7HM', 'A', 10 union all select 4, 124, '7HM', 'B', 20 union all select 5, 125, '7HM', 'A', 100 union all select 6, 125, '7HM', 'B', 200 union all select 7, 125, '7HM', 'C', 3 union all select 8, 126, '2EA', 'E', 4 union all select 8, 127, '2EA', 'E', 40 union all select 9, 128, '2EB', 'F', 5 union all select 9, 129, '2EB', 'F', 50 union all select 10, 130, '2EB', 'F', 500 GO SELECT * FROM #ProductSales GO /* And i would like to have the following result Product nrOfProducts CombinationRebateCode SumAmount ABC LOI XYZ 7HM 2 ABC, XYZ 33 11 0 22 2EB 2 LOI 44 0 44 0 .. */ CREATE TABLE #ProductRebateCode(Product varchar(6), nrOfProducts int, sumAmountRebateCombo int, rebateCodeCombination varchar(80), A int, B int, C int, E int, F int) Go INSERT INTO #ProductRebateCode select '7HM', 2, 33, 'A, B', 2, 2, 0, 0, 0 union all select '7HM', 1, 303, 'A, B, C', 1, 1, 1, 0, 0 union all select '2EA', 2, 44, 'E', 0, 0, 0, 2, 0 union all select '2EB', 3, 555, 'E', 0, 0, 0, 0, 2 Select * from #ProductRebateCode -- Drop Table #ProductSales IF EXISTS ( SELECT * FROM tempdb.dbo.sysobjects WHERE name LIKE '#ProductSales%') DROP TABLE #ProductSales -- Drop Table #ProductRebateCode IF EXISTS ( SELECT * FROM tempdb.dbo.sysobjects WHERE name LIKE '#ProductRebateCode%') DROP TABLE #ProductRebateCode I would like to have the result like in the example (see second select (#ProductRebateCode). I tried to achieve it with the crosstab from this post: http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=6216&whichpage=6. exec CrossTab2b @SQL = 'SELECT [ProductID], Product, RebateCode, Amount FROM #ProductSales' ,@PivotCol = 'RebateCode' ,@Summaries = 'Sum(Amount ELSE 0)[_Sum], Count([ProductID])[_nrOfProducts]' /* SUM(Amount ELSE 0)[Amount], COUNT(Amount)[Qty] */ ,@GroupBy = 'RebateCode, Product' ,@OtherFields = 'Product' I believe that this could work, but i am unable to solve it. Do you believe that it is possible to achieve what i am trying without MDX or the other fancy ?DX-Stuff? Best regards And Thanks a lot debugger the other

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  • C++ unrestricted union workaround

    - by Chris
    #include <stdio.h> struct B { int x,y; }; struct A : public B { // This whines about "copy assignment operator not allowed in union" //A& operator =(const A& a) { printf("A=A should do the exact same thing as A=B\n"); } A& operator =(const B& b) { printf("A = B\n"); } }; union U { A a; B b; }; int main(int argc, const char* argv[]) { U u1, u2; u1.a = u2.b; // You can do this and it calls the operator = u1.a = (B)u2.a; // This works too u1.a = u2.a; // This calls the default assignment operator >:@ } Is there any workaround to be able to do that last line u1.a = u2.a with the exact same syntax, but have it call the operator = (don't care if it's =(B&) or =(A&)) instead of just copying data? Or are unrestricted unions (not supported even in Visual Studio 2010) the only option?

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  • Sum of a summation in mysql

    - by dames
    I have the following query, in the top select statement (sum(l.app_ln_amnt)/count(l.app_ln_amnt)) works well but in the union I want to find the total of (sum(l.app_ln_amnt)/count(l.app_ln_amnt)) query from the top select statement However my solution seems to be off I need some help please select (sum(l.app_ln_amnt)/count(l.app_ln_amnt)), from receipt_history l UNION select SUM(sum(l.app_ln_amnt)/count(l.app_ln_amnt)), from receipt_history l

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  • Merge overlapping date intervals

    - by leoinfo
    Is there a better way of merging overlapping date intervals? The solution I came up with is so simple that now I wonder if someone else has a better idea of how this could be done. /***** DATA EXAMPLE *****/ DECLARE @T TABLE (d1 DATETIME, d2 DATETIME) INSERT INTO @T (d1, d2) SELECT '2010-01-01','2010-03-31' UNION SELECT '2010-04-01','2010-05-31' UNION SELECT '2010-06-15','2010-06-25' UNION SELECT '2010-06-26','2010-07-10' UNION SELECT '2010-08-01','2010-08-05' UNION SELECT '2010-08-01','2010-08-09' UNION SELECT '2010-08-02','2010-08-07' UNION SELECT '2010-08-08','2010-08-08' UNION SELECT '2010-08-09','2010-08-12' UNION SELECT '2010-07-04','2010-08-16' UNION SELECT '2010-11-01','2010-12-31' UNION SELECT '2010-03-01','2010-06-13' /***** INTERVAL ANALYSIS *****/ WHILE (1=1) BEGIN UPDATE t1 SET t1.d2 = t2.d2 FROM @T AS t1 INNER JOIN @T AS t2 ON DATEADD(day, 1, t1.d2) BETWEEN t2.d1 AND t2.d2 -- AND t1.d2 <= t2.d2 /***** this condition is useless *****/ IF @@ROWCOUNT = 0 BREAK END /***** RESULT *****/ SELECT StartDate = MIN(d1) , EndDate = d2 FROM @T GROUP BY d2 ORDER BY StartDate, EndDate /***** OUTPUT *****/ /***** StartDate EndDate 2010-01-01 2010-06-13 2010-06-15 2010-08-16 2010-11-01 2010-12-31 *****/ EDIT: I realized that the t1.d2 <= t2.d2 condition is not really useful.

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  • Select Union Query problem

    - by Krishma
    I have 2 tables Table A id name ------------ 1 Scott 2 Dan 3 Sam Table B id name ------------ 1 Dan 2 Andi 3 Jess Result needs to be Id Name Found 1 Scott A 2 Dan C i.e. found in both 3 Sam A 2 Andi B 3 Jess B I am able to do UNION to fetch the result but how i generate column Founds. Any idea ?? Thank you in advance :)

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  • how to get records from subquery using union in linq

    - by varun
    sql = " SELECT * FROM userDetail "; sql += " WHERE userId IN "; sql += " (SELECT friendId FROM userFriends "; sql += " WHERE approvalStatus='True' AND userId=" + userId; sql += " UNION"; sql += " SELECT userId FROM userFriends "; sql += " WHERE approvalStatus='True' AND friendId=" + userId + ")";

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  • Excel VBA / SQL Union

    - by Edge
    Hi, I am trying to Join 2 seperate columns from 2 different sheets to make a longer column from which i can then use a Vlookup from. Sheet1 A, B, C, D, E, F, G Sheet2 A, B, C, D, E, F, G I want to Join(Union) Columns B from sheet1 and C from sheet2 together and find the Distinct values of the new list. I have been working on this for weeks. Thanks

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  • how to specify literal value in linq union

    - by lowlyintern
    I have the following SQL query, note I want the literal value '0' in the second field in the second SELECT statement from the ItemSale table. How do I express this in LINQ? I get the error message 'Invalid anonymous type member declarator'. SELECT BranchNumber,QuantitySold FROM Department UNION SELECT BranchNumber,0 FROM ItemSale How to express the '0' in LINQ? var unionQuery = (from dept in Department select new { dept.BranchNumber, dept.QuantitySold, }) .Concat(from item in ItemSale select new { item.BranchNumber, 0 });

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  • How can I decrease time opening myisam table in an "union all" of the same table??

    - by parm.95
    I have a myisam table with 2.5M rows, I use an union all to get my results as following: (SELECT t.id FROM t WHERE type=1 LIMIT 10) UNION ALL (SELECT t.id FROM t WHERE type=2 LIMIT 10) ... UNION ALL (SELECT t.id FROM t WHERE type=25 LIMIT 10) the time to opening the table t is about 6ms. With a single request: SELECT t.id FROM t WHERE type=1 LIMIT 10 the time is about 1ms. What I don't understand is why mysql spend more time to the same table in union all. It should recognize that is the same table and so just opening at the first union. Does anybody can help me to decrease the time for opening table in a "union all"? Thanks in advance!

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  • Query table value aliasing in Oracle SQL

    - by Strata
    I have a homework assignment in SQL for Oracle 10g where I have to apply union to two different select statements, to return two columns. I need the values of each cell under vendor_state to indicate CA and every other value in another state to return "Outside CA", to indicate they're elsewhere. I applied the union and produced the two columns and the listings for CA, but many other state IDs were listed and I couldn't find an explanation for how to change the actual values in the query itself. Eventually, I stumbled on an answer, but I can't explain why this works. The code is as follows: SELECT vendor_name, vendor_state FROM vendors WHERE vendor_state IN 'CA' UNION SELECT vendor_name, 'Outside CA' AS vendor_state FROM vendors WHERE vendor_state NOT IN 'CA' ORDER BY vendor_name This gives me the exact answer I need, but I don't know why the aliasing in the second select statement can behave this way....no explanation is given in my textbook and nothing I've read indicates that column aliasing can be done like this. But, by switching the column name and the alias value, I have replaced the value being returned rather than the column name itself...I'm not complaining about the result, but it would help if I knew how I did it.

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  • request for member view in something not a structure or union

    - by james
    Hi I have this error when i build my application iphone: request for member view in something not a structure or union on [CommuneSlider.view removeFromSuperview]; the code: - (void) CommuneSelected { CommuneDetailsViewController *com = [[CommuneDetailsViewController alloc] initWithNibName:@"CommuneDetailsViewController" bundle:nil]; UINavigationController *navig = [[UINavigationController alloc] initWithRootViewController:com]; [self setCommuneDetails:(CommuneDetailsViewController *) navig]; [navig setNavigationBarHidden:YES]; [com release]; [navig release]; [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:.8]; [UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:window cache:YES]; [CommuneSlider.view removeFromSuperview]; [self.window addSubview:[CommuneDetails view]]; [UIView commitAnimations]; } need HELP

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  • iPhone Core Data: request for member 'tableView' in something not a structure or union

    - by Nic Hubbard
    I am trying to use CoreData to populate a UITableView. I have been using the developer "Locations" project, and I think I have everything correct. But, now I am getting the following error when I build: request for member 'tableView' in something not a structure or union Why would it be confused about tableView? I am using it many times in the methods. The errors seem to be coming from: [self.tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES]; Ideas?

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  • compilation error: request member in something not a structure of union

    - by Fantastic Fourier
    Hi everybody, I'm having the above error request member rv in something not a structure of union. I've googled it and several answers told me it's when working with a pointer but tries to access it as a struct, where I should be using -> instead of . int foo(void * arg, struct message * msg) { struct fd_info * info = (struct something *) arg; int * socks[MAX_CONNECTION]; socks = &(info->_socks); // where int * _socks[MAX_CONNECTION] in struct info // do other things rv = sendto(socks[i], &msg, sizeof(&msg), NULL, &(csys->client_address), sizeof(csys->client_address)); ... } The problem is all of the arguments i have are pointers. i'm confused as to what is wrong. thanks to any comments/thoughts.

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  • SqlServer2008 + expensive union

    - by Tim Mahy
    Hi al, we have 5 tables over which we should query with user search input throughout a stored procedure. We do a union of the similar data inside a view. Because of this the view can not be materialized. We are not able to change these 5 tables drastically (like creating a 6th table that contains the similar data of the 5 tables and reference that new one from the 5 tables). The query is rather expensive / slow what are our other options? It's allowed to think outside the box. Unfortunately I cannot give more information like the table/view/SP definition because of customer confidentiality... greetings, Tim

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  • SqlServer2008 + expensive union all

    - by Tim Mahy
    Hi al, we have 5 tables over which we should query with user search input throughout a stored procedure. We do a union all of the similar data inside a view. Because of this the view can not be materialized. We are not able to change these 5 tables drastically (like creating a 6th table that contains the similar data of the 5 tables and reference that new one from the 5 tables). The query is rather expensive / slow what are our other options? It's allowed to think outside the box. Unfortunately I cannot give more information like the table/view/SP definition because of customer confidentiality... greetings, Tim

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  • SQL Server 2008 + expensive union all

    - by Tim Mahy
    Hi al, we have 5 tables over which we should query with user search input throughout a stored procedure. We do a union all of the similar data inside a view. Because of this the view can not be materialized. We are not able to change these 5 tables drastically (like creating a 6th table that contains the similar data of the 5 tables and reference that new one from the 5 tables). The query is rather expensive / slow what are our other options? It's allowed to think outside the box. Unfortunately I cannot give more information like the table/view/SP definition because of customer confidentiality... greetings, Tim

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  • How to UNION ALL two SELECT statements?

    - by Lisa
    I have 2 tables, one looks like this: TABLE ONE id | Last Name | First Name | Username | Password | Secret Question and another that looks like this: TABLE TWO id | Hobby | Country | I want to combine a Select statement that grabs data from both tables and output the results. The following code: $select = mysql_query(" SELECT * FROM table_one WHERE Username = 'Bob' UNION ALL SELECT * FROM table_two WHERE Hobby = 'Baseball' "); while ($return = mysql_fetch_assoc($select)) { $userName = $return['Username']; $hobby = $return['Hobby']; } echo "$userName likes $hobby"; results in a The used SELECT statements have a different number of columns error, what am I doing wrong?

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  • LINQ to Objects .Distinct() not pulling distinct objects

    - by Anthony Potts
    I have two ways that I am doing a fuzzy search for a customer. One is by an abbreviated name and the other is by the customers full name. When I take these two and then union them together (which I have read several places should remove distinct values) I get duplicates. Thinking that all I need to do is then call the .Distinct() method on this I also still get Duplicates. Do I need to implement some compare functionality in my customer object? My code: Dim shortNameMatch As List(Of ICustomer) = CustomerLibrary.GetCustomersByShortName(term) Dim custNameMatch As List(Of ICustomer) = CustomerLibrary.GetCustomersByCustName(term) Dim allMatch = (From a In (From s In shortNameMatch Select s).Union(From c In custNameMatch Select c) Select a).Distinct()

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  • Java constructor and modify the object properties at runtime

    - by lupin
    Note: This is an assignment Hi, I have the following class/constructor. import java.io.*; class Set { public int numberOfElements = 0; public String[] setElements = new String[5]; public int maxNumberOfElements = 5; // constructor for our Set class public Set(int numberOfE, int setE, int maxNumberOfE) { int numberOfElements = numberOfE; String[] setElements = new String[setE]; int maxNumberOfElements = maxNumberOfE; } // Helper method to shorten/remove element of array since we're using basic array instead of ArrayList or HashSet from collection interface :( static String[] removeAt(int k, String[] arr) { final int L = arr.length; String[] ret = new String[L - 1]; System.arraycopy(arr, 0, ret, 0, k); System.arraycopy(arr, k + 1, ret, k, L - k - 1); return ret; } int findElement(String element) { int retval = 0; for ( int i = 0; i < setElements.length; i++) { if ( setElements[i] != null && setElements[i].equals(element) ) { return retval = i; } retval = -1; } return retval; } void add(String newValue) { int elem = findElement(newValue); if( numberOfElements < maxNumberOfElements && elem == -1 ) { setElements[numberOfElements] = newValue; numberOfElements++; } } int getLength() { if ( setElements != null ) { return setElements.length; } else { return 0; } } String[] emptySet() { setElements = new String[0]; return setElements; } Boolean isFull() { Boolean True = new Boolean(true); Boolean False = new Boolean(false); if ( setElements.length == maxNumberOfElements ){ return True; } else { return False; } } Boolean isEmpty() { Boolean True = new Boolean(true); Boolean False = new Boolean(false); if ( setElements.length == 0 ) { return True; } else { return False; } } void remove(String newValue) { for ( int i = 0; i < setElements.length; i++) { if ( setElements[i].equals(newValue) ) { setElements = removeAt(i,setElements); } } } int isAMember(String element) { int retval = -1; for ( int i = 0; i < setElements.length; i++ ) { if (setElements[i] != null && setElements[i].equals(element)) { return retval = i; } } return retval; } void printSet() { for ( int i = 0; i < setElements.length; i++) { System.out.println("Member elements on index: "+ i +" " + setElements[i]); } } String[] getMember() { String[] tempArray = new String[setElements.length]; for ( int i = 0; i < setElements.length; i++) { if(setElements[i] != null) { tempArray[i] = setElements[i]; } } return tempArray; } Set union(Set x, Set y) { String[] newXtemparray = new String[x.getLength()]; String[] newYtemparray = new String[y.getLength()]; Set temp = new Set(1,20,20); newXtemparray = x.getMember(); newYtemparray = x.getMember(); for(int i = 0; i < newXtemparray.length; i++) { temp.add(newYtemparray[i]); } for(int j = 0; j < newYtemparray.length; j++) { temp.add(newYtemparray[j]); } return temp; } } // This is the SetDemo class that will make use of our Set class class SetDemo { public static void main(String[] args) { //get input from keyboard BufferedReader keyboard; InputStreamReader reader; String temp = ""; reader = new InputStreamReader(System.in); keyboard = new BufferedReader(reader); try { System.out.println("Enter string element to be added" ); temp = keyboard.readLine( ); System.out.println("You entered " + temp ); } catch (IOException IOerr) { System.out.println("There was an error during input"); } /* ************************************************************************** * Test cases for our new created Set class. * ************************************************************************** */ Set setA = new Set(1,10,10); setA.add(temp); setA.add("b"); setA.add("b"); setA.add("hello"); setA.add("world"); setA.add("six"); setA.add("seven"); setA.add("b"); int size = setA.getLength(); System.out.println("Set size is: " + size ); Boolean isempty = setA.isEmpty(); System.out.println("Set is empty? " + isempty ); int ismember = setA.isAMember("sixb"); System.out.println("Element six is member of setA? " + ismember ); Boolean output = setA.isFull(); System.out.println("Set is full? " + output ); setA.printSet(); int index = setA.findElement("world"); System.out.println("Element b located on index: " + index ); setA.remove("b"); setA.emptySet(); int resize = setA.getLength(); System.out.println("Set size is: " + resize ); setA.printSet(); Set setB = new Set(0,10,10); Set SetA = setA.union(setB,setA); SetA.printSet(); } } I have two question here, why I when I change the class property declaration to: class Set { public int numberOfElements; public String[] setElements; public int maxNumberOfElements; // constructor for our Set class public Set(int numberOfE, int setE, int maxNumberOfE) { int numberOfElements = numberOfE; String[] setElements = new String[setE]; int maxNumberOfElements = maxNumberOfE; } I got this error: \ javaprojects>java SetDemo Enter string element to be added a You entered a Exception in thread "main" java.lang.NullPointerException at Set.findElement(Set.java:30) at Set.add(Set.java:43) at SetDemo.main(Set.java:169) Second, on the union method, why the result of SetA.printSet still printing null, isn't it getting back the return value from union method? Thanks in advance for any explaination. lupin

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  • Complex Rails queries across multiple tables, unions, and will_paginate. Solved.

    - by uberllama
    Hi folks. I've been working on a complex "user feed" type of functionality for a while now, and after experimenting with various union plugins, hacking named scopes, and brute force, have arrived at a solution I'm happy with. S.O. has been hugely helpful for me, so I thought I'd post it here in hopes that it might help others and also to get feedback -- it's very possible that I worked on this so long that I walked down an unnecessarily complicated road. For the sake of my example, I'll use users, groups, and articles. A user can follow other users to get a feed of their articles. They can also join groups and get a feed of articles that have been added to those groups. What I needed was a combined, pageable feed of distinct articles from a user's contacts and groups. Let's begin. user.rb has_many :articles has_many :contacts has_many :contacted_users, :through => :contacts has_many :memberships has_many :groups, :through => :memberships contact.rb belongs_to :user belongs_to :contacted_user, :class_name => "User", :foreign_key => "contacted_user_id" article.rb belongs_to :user has_many :submissions has_many :groups, :through => :submissions group.rb has_many :memberships has_many :users, :through => :memberships has_many :submissions has_many :articles, :through => :submissions Those are the basic models that define my relationships. Now, I add two named scopes to the Article model so that I can get separate feeds of both contact articles and group articles should I desire. article.rb # Get all articles by user's contacts named_scope :by_contacts, lambda {|user| {:joins => "inner join contacts on articles.user_id = contacts.contacted_user_id", :conditions => ["articles.published = 1 and contacts.user_id = ?", user.id]} } # Get all articles in user's groups. This does an additional query to get the user's group IDs, then uses those in an IN clause named_scope :by_groups, lambda {|user| {:select => "DISTINCT articles.*", :joins => :submissions, :conditions => {:submissions => {:group_id => user.group_ids}}} } Now I have to create a method that will provide a UNION of these two feeds into one. Since I'm using Rails 2.3.5, I have to use the construct_finder_sql method to render a scope into its base sql. In Rails 3.0, I could use the to_sql method. user.rb def feed "(#{Article.by_groups(self).send(:construct_finder_sql,{})}) UNION (#{Article.by_contacts(self).send(:construct_finder_sql,{})})" end And finally, I can now call this method and paginate it from my controller using will_paginate's paginate_by_sql method. HomeController.rb @articles = Article.paginate_by_sql(current_user.feed, :page => 1) And we're done! It may seem simple now, but it was a lot of work getting there. Feedback is always appreciated. In particular, it would be great to get away from some of the raw sql hacking. Cheers.

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