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  • ORACLE: can we create global temp tables or any tables in stored proc?

    - by mrp
    Hi, below is the stored proc I wrote: create or replace procedure test005 as begin CREATE GLOBAL TEMPORARY TABLE TEMP_TRAN ( COL1 NUMBER(9), COL2 VARCHAR2(30), COL3 DATE ) ON COMMIT PRESERVE ROWS / INSERT INTO TEMP_TRAN VALUES(1,'D',sysdate); INSERT INTO TEMP_TRAN VALUES(2,'I',sysdate); INSERT INTO TEMP_TRAN VALUES(3,'s',sysdate); COMMIT; end; when i executed it , i get an error message mentioning: create or replace procedure test005 as begin CREATE GLOBAL TEMPORARY TABLE TEMP_TRAN ( COL1 NUMBER(9), COL2 VARCHAR2(30), COL3 DATE ) ON COMMIT PRESERVE ROWS / INSERT INTO TEMP_TRAN VALUES(1,'D',sysdate); INSERT INTO TEMP_TRAN VALUES(2,'I',sysdate); INSERT INTO TEMP_TRAN VALUES(3,'s',sysdate); COMMIT; end; Error at line 1 ORA-00955: name is already used by an existing object Script Terminated on line 1. I tried to drop the TEMP_TRAN and it says table doesn't exist. So there is no TEMP_TRAN table existed in system. why am I getting this error? I am using TOAD to create this stored proc. Any help would be highly appreciated.

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  • Query next/previous record

    - by Rob
    I'm trying to find a better way to get the next or previous record from a table. Let's say I have a blog or news table: CREATE TABLE news ( news_id INT UNSIGNED NOT NULL PRIMARY KEY AUTO_INCREMENT, news_datestamp DATETIME NOT NULL, news_author VARCHAR(100) NOT NULL, news_title VARCHAR(100) NOT NULL, news_text MEDIUMTEXT NOT NULL ); Now on the frontend I want navigation buttons for the next or previous records, if i'm sorting by news_id, I can do something rather simple like: SELECT MIN(news_id) AS next_news_id FROM news WHERE news_id > '$old_news_id' LIMIT 1 SELECT MAX(news_id) AS prev_news_id FROM news WHERE news_id < '$old_news_id' LIMIT 1 But the news can be sorted by any field, and I don't necessarily know which field is sorted on, so this won't work if the user sorts on news_author for example. I've resorted to the rather ugly and inefficient method of sorting the entire table and looping through all records until I find the record I need. $res = mysql_query("SELECT news_id FROM news ORDER BY `$sort_column` $sort_way"); $found = $prev = $next = 0; while(list($id) = mysql_fetch_row($res)) { if($found) { $next = $id; break; } if($id == $old_news_id) { $found = true; continue; } $prev = $id; } There's got to be a better way.

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  • From Servlet to JSP

    - by kawtousse
    When trying to pass a table built with HTML in my servlet like that: response.setContentType("text/html" ); PrintWriter out = response.getWriter(); out.println("<html>" ); out.println("<head>" ); out.println("<title>Imput OPC</title>" ); out.println("</head>" ); out.println("<body>" ); ... and then response.sendRedirect("/xxx.jsp" ); But I did not found any table in the JSP. A friend told me to use a Bean but how can i catch values from the form ( because I have a treatement with the form before constructing table)in a bean.I must use a servlet for that. So what I want is exactly to construct in the response a table then send it to jsp knowing that: .sendRedirect and getServletContext().getRequestDispatcher("/xxx.jsp").forward(request, response); gives nothing at all. Please Help its urgent. Thinks.

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  • VB.NET Update Access Database with DataTable

    - by sinDizzy
    I've been perusing some hep forums and some help books but cant seem to get my head wrapped around this. My task is to read data from two text files and then load that data into an existing MS Access 2007 database. So here is what i'm trying to do: Read data from first text file and for every line of data add data to a DataTable using CarID as my unique field. Read data from second text file and look for existing CarID in DataTable if exists update that row. If it doesnt exist add a new row. once im done push the contents of the DataTable to the database. What i have so far: Dim sSQL As String = "SELECT * FROM tblCars" Dim da As New OleDb.OleDbDataAdapter(sSQL, conn) Dim ds As New DataSet da.Fill(ds, "CarData") Dim cb As New OleDb.OleDbCommandBuilder(da) 'loop read a line of text and parse it out. gets dd, dc, and carId 'create a new empty row Dim dsNewRow As DataRow = ds.Tables("CarData").NewRow() 'update the new row with fresh data dsNewRow.Item("DriveDate") = dd dsNewRow.Item("DCode") = dc dsNewRow.Item("CarNum") = carID 'about 15 more fields 'add the filled row to the DataSet table ds.Tables("CarData").Rows.Add(dsNewRow) 'end loop 'update the database with the new rows da.Update(ds, "CarData") Questions: In constructing my table i use "SELECT * FROM tblCars" but what if that table has millions of records already. Is that not a waste of resources? Should i be trying something different if i want to update with new records? Once Im done with the first text file i then go to my next text file. Whats the best approach here: To First look for an existing record based on CarNum or to create a second table and then merge the two at the end? Finally when the DataTable is done being populated and im pushing it to the database i want to make sure that if records already exist with three primary fields (DriveDate, DCode, and CarNum) that they get updated with new fields and if it doesn't exist then those records get appended. Is that possible with my process? tia AGP

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  • how to model a follower stream in appengine?

    - by molicule
    I am trying to design tables to buildout a follower relationship. Say I have a stream of 140char records that have user, hashtag and other text. Users follow other users, and can also follow hashtags. I am outlining the way I've designed this below, but there are two limitaions in my design. I was wondering if others had smarter ways to accomplish the same goal. The issues with this are The list of followers is copied in for each record If a new follower is added or one removed, 'all' the records have to be updated. The code class HashtagFollowers(db.Model): """ This table contains the followers for each hashtag """ hashtag = db.StringProperty() followers = db.StringListProperty() class UserFollowers(db.Model): """ This table contains the followers for each user """ username = db.StringProperty() followers = db.StringListProperty() class stream(db.Model): """ This table contains the data stream """ username = db.StringProperty() hashtag = db.StringProperty() text = db.TextProperty() def save(self): """ On each save all the followers for each hashtag and user are added into a another table with this record as the parent """ super(stream, self).save() hfs = HashtagFollowers.all().filter("hashtag =", self.hashtag).fetch(10) for hf in hfs: sh = streamHashtags(parent=self, followers=hf.followers) sh.save() ufs = UserFollowers.all().filter("username =", self.username).fetch(10) for uf in ufs: uh = streamUsers(parent=self, followers=uf.followers) uh.save() class streamHashtags(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() class streamUsers(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() Now, to get the stream of followed hastags indexes = db.GqlQuery("""SELECT __key__ from streamHashtags where followers = 'myusername'""") keys = [k,parent() for k in indexes[offset:numresults]] return db.get(keys) Is there a smarter way to do this?

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  • Getting the most recent post based on date

    - by camcim
    Hi guys, How do I go about displaying the most recent post when I have two tables, both containing a column called creation_date This would be simple if all I had to do was get the most recent post based on posts created_on value however if a post contains replies I need to factor this into the equation. If a post has a more recent reply I want to get the replies created_on value but also get the posts post_id and subject. The posts table structure: CREATE TABLE `posts` ( `post_id` bigint(20) unsigned NOT NULL auto_increment, `cat_id` bigint(20) NOT NULL, `user_id` bigint(20) NOT NULL, `subject` tinytext NOT NULL, `comments` text NOT NULL, `created_on` datetime NOT NULL, `status` varchar(10) NOT NULL default 'INACTIVE', `private_post` varchar(10) NOT NULL default 'PUBLIC', `db_location` varchar(10) NOT NULL, PRIMARY KEY (`post_id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=7 ; The replies table structure: CREATE TABLE `replies` ( `reply_id` bigint(20) unsigned NOT NULL auto_increment, `post_id` bigint(20) NOT NULL, `user_id` bigint(20) NOT NULL, `comments` text NOT NULL, `created_on` datetime NOT NULL, `notify` varchar(5) NOT NULL default 'YES', `status` varchar(10) NOT NULL default 'INACTIVE', `db_location` varchar(10) NOT NULL, PRIMARY KEY (`reply_id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ; Here is my query so far. I've removed my attempt of extracting the dates. $strQuery = "SELECT posts.post_id, posts.created_on, replies.created_on, posts.subject "; $strQuery = $strQuery."FROM posts ,replies "; $strQuery = $strQuery."WHERE posts.post_id = replies.post_id "; $strQuery = $strQuery."AND posts.cat_id = '".$row->cat_id."'";

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  • Controls.remove() method not working in asp.net

    - by user279521
    I have a web app where the user can create dynamic textboxes at run time. When the user clicks SUBMIT, the form sends data to the database and I want remove the dynamic controls. The controls are created in the following code: Table tb = new Table(); tb.ID = "tbl"; for (i = 0; i < myCount; i += 1) { TableRow tr = new TableRow(); TextBox txtEmplName = new TextBox(); TextBox txtEmplEmail = new TextBox(); TextBox txtEmplPhone = new TextBox(); TextBox txtEmplPosition = new TextBox(); TextBox txtEmplOfficeID = new TextBox(); txtEmplName.ID = "txtEmplName" + i.ToString(); txtEmplEmail.ID = "txtEmplEmail" + i.ToString(); txtEmplPhone.ID = "txtEmplPhone" + i.ToString(); txtEmplPosition.ID = "txtEmplPosition" + i.ToString(); txtEmplOfficeID.ID = "txtEmplOfficeID" + i.ToString(); tr.Cells.Add(tc); tb.Rows.Add(tr); } Panel1.Controls.Add(tb); The Remove section of the code is: Table t = (Table)Page.FindControl("Panel1").FindControl("tbl"); foreach (TableRow tr in t.Rows) { for (i = 1; i < myCount; i += 1) { string txtEmplName = "txtEmplName" + i; tr.Controls.Remove(t.FindControl(txtEmplName)); string txtEmplEmail = "txtEmplEmail" + i; tr.Controls.Remove(t.FindControl(txtEmplEmail)); string txtEmplPhone = "txtEmplPhone" + i; tr.Controls.Remove(t.FindControl(txtEmplPhone)); string txtEmplPosition = "txtEmplPosition" + i; tr.Controls.Remove(t.FindControl(txtEmplPosition)); string txtEmplOfficeID = "txtEmplOfficeID" + i; tr.Controls.Remove(t.FindControl(txtEmplOfficeID)); } } However, the textboxes are still visible. Any ideas?

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  • Converting ntext to nvcharmax(max) - Getting around size limitation

    - by Overflew
    Hi all, I'm trying to change an existing SQL NText column to nvcharmax(max), and encountering an error on the size limit. There's a large amount of existing data, some of which is more than the 8k limit, I believe. We're looking to convert this, so that the field is searchable in LINQ. The 2x SQL statements I've tried are: update Table set dataNVarChar = convert(nvarchar(max), dataNtext) where dataNtext is not null update Table set dataNVarChar = cast(dataNtext as nvarchar(max)) where dataNtext is not null And the error I get is: Cannot create a row of size 8086 which is greater than the allowable maximum row size of 8060. This is using SQL Server 2008. Any help appreciated, Thanks. Update / Solution: The marked answer below is correct, and SQL 2008 can change the column to the correct data type in my situation, and there are no dramas with the LINQ-utilising application we use on top of it: alter table [TBL] alter column [COL] nvarchar(max) I've also been advised to follow it up with: update [TBL] set [COL] = [COL] Which completes the conversion by moving the data from the lob structure to the table (if the length in less than 8k), which improves performance / keeps things proper.

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  • Database design: Calculating the Account Balance

    - by 001
    How do I design the database to calculate the account balance? 1) Currently I calculate the account balance from the transaction table In my transaction table I have "description" and "amount" etc.. I would then add up all "amount" values and that would work out the user's account balance. I showed this to my friend and he said that is not a good solution, when my database grows its going to slow down???? He said I should create separate table to store the calculated account balance. If did this, I will have to maintain two tables, and its risky, the account balance table could go out of sync. Any suggestion? EDIT: OPTION 2: should I add an extra column to my transaction tables "Balance". now I do not need to go through many rows of data to perform my calculation. Example John buys $100 credit, he debt $60, he then adds $200 credit. Amount $100, Balance $100. Amount -$60, Balance $40. Amount $200, Balance $240.

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  • How to store unlimited characters in Oracle 11g?

    - by vicky21
    We have a table in Oracle 11g with a varchar2 column. We use a proprietary programming language where this column is defined as string. Maximum we can store 2000 characters (4000 bytes) in this column. Now the requirement is such that the column needs to store more than 2000 characters (in fact unlimited characters). The DBAs don't like BLOB or LONG datatypes for maintenance reasons. The solution that I can think of is to remove this column from the original table and have a separate table for this column and then store each character in a row, in order to get unlimited characters. This tble will be joined with the original table for queries. Is there any better solution to this problem? UPDATE: The proprietary programming language allows to define variables of type string and blob, there is no option of CLOB. I understand the responses given, but I cannot take on the DBAs. I understand that deviating from BLOB or LONG will be developers' nightmare, but still cannot help it.

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  • How to determine one to many column name from entity type

    - by snicker
    I need a way to determine the name of the column used by NHibernate to join one-to-many collections from the collected entity's type. I need to be able to determine this at runtime. Here is an example: I have some entities: namespace Entities { public class Stable { public virtual int Id {get; set;} public virtual string StableName {get; set;} public virtual IList<Pony> Ponies { get; set; } } public class Dude { public virtual int Id { get; set; } public virtual string DudesName { get; set; } public virtual IList<Pony> PoniesThatBelongToDude { get; set; } } public class Pony { public virtual int Id {get; set;} public virtual string Name {get; set;} public virtual string Color { get; set; } } } I am using NHibernate to generate the database schema, which comes out looking like this: create table "Stable" (Id integer, StableName TEXT, primary key (Id)) create table "Dude" (Id integer, DudesName TEXT, primary key (Id)) create table "Pony" (Id integer, Name TEXT, Color TEXT, Stable_id INTEGER, Dude_id INTEGER, primary key (Id)) Given that I have a Pony entity in my code, I need to be able to find out: A. Does Pony even belong to a collection in the mapping? B. If it does, what are the column names in the database table that pertain to collections In the above instance, I would like to see that Pony has two collection columns, Stable_id and Dude_id.

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  • Child divs not taking parent height

    - by Hiral
    I want height of children div .cell to take up 100% height of parent. But it is not happening. HTML: <div class="header"> header </div> <div class="wrapper"> <div class="padding"> <div class="table bg"> <div class="cell"> hello world </div> <div class="cell"> dummy text </div> </div> </div> </div> <div class="footer"> footer </div> CSS: html,body{height:100%;} body{margin:0;padding:0;} .footer,.header{background:black;height:30px;color:white;} .wrapper{min-height:calc(100% - 60px);height:auto !important;} .padding{padding:20px;} .table{display:table;width:100%;} .cell{display:table-cell;} .bg{background:#ccc;} I think it is not happening because I have .wrapper{min-height:calc(100% - 60px);height:auto !important;} It happens if I change .wrapper to .wrapper{height:calc(100% - 60px);} then it is happening. Here is the fiddle.

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  • Need Associated ID Added to a While Loop (php)

    - by user319361
    Been trying to get my head around while loops for the last few days but the code seems very inefficient for what Im trying to achieve. I'm assuming I'm overcomplicating this though nothing I've tried seems to work. Each topic in my forum can have related topic IDs stored in a seperate table. A post ID is also stored in this table, as that specific post references why they are considered related. DB Table contains only: topic_id, related_id, post_id // Get related IDs and post IDs for current topic being viewed $result = $db->query('SELECT related_id, post_id FROM related_topics WHERE topic_id='.$id.''); // If related topics found, put both of the IDs into arrays if ($db->num_rows($result)) { while($cur_related = mysql_fetch_array($result)){ $reltopicarray[] = $cur_related['related_id']; $relpost[] = $cur_related['post_id']; } // If the first array isnt empty, get some additional info about each related ID from another table if(!empty($reltopicarray)) { $pieces = $reltopicarray; $glued = "\"".implode('", "', $pieces)."\""; $fetchtopics = $db->query('SELECT id, subject, author, image, etc FROM topics WHERE id IN('.$glued.')'); } // Print each related topic while($related = mysql_fetch_array($fetchtopics)){ ?> <a href="view.php?id=<?php echo $related['id']; ?>"><?php echo $related['subject']; ?></a> by <?php echo $related['author']; ?> // Id like to show the Post ID below (from the array in the first while loop) // The below link doesnt work as Im outside the while loop by this point. <br /><a href="view.php?post_id=<?php echo $cur_related['post_id']; ?>">View Relationship</a> <?php } ?> The above currently works, however I'm trying to also display the post_id link below each related topic link, as shown above. Would be greatful if someone can lend a hand. Thanks :)

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  • GROUP BY ID range?

    - by d0ugal
    Given a data set like this; +-----+---------------------+--------+ | id | date | result | +-----+---------------------+--------+ | 121 | 2009-07-11 13:23:24 | -1 | | 122 | 2009-07-11 13:23:24 | -1 | | 123 | 2009-07-11 13:23:24 | -1 | | 124 | 2009-07-11 13:23:24 | -1 | | 125 | 2009-07-11 13:23:24 | -1 | | 126 | 2009-07-11 13:23:24 | -1 | | 127 | 2009-07-11 13:23:24 | -1 | | 128 | 2009-07-11 13:23:24 | -1 | | 129 | 2009-07-11 13:23:24 | -1 | | 130 | 2009-07-11 13:23:24 | -1 | | 131 | 2009-07-11 13:23:24 | -1 | | 132 | 2009-07-11 13:23:24 | -1 | | 133 | 2009-07-11 13:23:24 | -1 | | 134 | 2009-07-11 13:23:24 | -1 | | 135 | 2009-07-11 13:23:24 | -1 | | 136 | 2009-07-11 13:23:24 | -1 | | 137 | 2009-07-11 13:23:24 | -1 | | 138 | 2009-07-11 13:23:24 | 1 | | 139 | 2009-07-11 13:23:24 | 0 | | 140 | 2009-07-11 13:23:24 | -1 | +-----+---------------------+--------+ How would I go about grouping the results by day 5 records at a time. The above results is part of the live data, there is over 100,000 results rows in the table and its growing. Basically I want to measure the change over time, so want to take a SUM of the result every X records. In the real data I'll be doing it ever 100 or 1000 but for the data above perhaps every 5. If i could sort it by date I would do something like this; SELECT DATE_FORMAT(date, '%h%i') ym, COUNT(result) 'Total Games', SUM(result) as 'Score' FROM nn_log GROUP BY ym; I can't figure out a way of doing something similar with numbers. The order is sorted by the date but I hope to split the data up every x results. It's safe to assume there are no blank rows. Doing it above with the data you could do multiple selects like; SELECT SUM(result) FROM table LIMIT 0,5; SELECT SUM(result) FROM table LIMIT 5,5; SELECT SUM(result) FROM table LIMIT 10,5; Thats obviously not a very good way to scale up to a bigger problem. I could just write a loop but I'd like to reduce the number of queries.

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  • Enabling Compiz Viewport Switcher key bindings

    - by David Moles
    I'm running compiz 0.8.2 with compizconfig on Scientific Linux 6.2 with Gnome 2.28.2. In the compizconfig "General Options" I have "Desktop Size" set as follows: Horizontal Virtual Size: 6 Vertical Virtual Size: 1 Number of Desktops: 1 This gets me the layout I want, i.e. 6 workspaces in a horizontal layout. Ctrl-alt-cursor-keys work fine for switching between them. However, I can't figure out how to get key bindings for specific workspaces. I've tried enabling "Viewport Switcher" in compizconfig, and tried various combinations both in "Number-based viewport switching" and "Go to specific viewport", to no apparent effect. My first thought was that something else was eating the specific key bindings I chose, but I think I've tried every combination of shift, control, alt and super (i.e., the Windows key) by now. I tried setting 6 desktops under "General Options" instead of one desktop with horizontal virtual size 6, but that doesn't seem to make a difference either. What am I missing?

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  • how to display values of an arraylist defined in servlet using ajax call

    - by veena123
    can anyone please help me with below code servlet: below servlet is for statically defining an array. import java.io.; import javax.servlet.; import javax.servlet.http.; import java.util.; public class SampleAjax extends HttpServlet{ public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException,IOException { response.setContentType("text/html"); string plociyno = "abd1234"; PrintWriter pw = response.getWriter(); if (policyno.equals("abc1234")) { List dataList= new ArrayList(); dataList.add("automated refund possible"); request.setAttribute("data",dataList); RequestDispatcher dispatcher = request.getRequestDispatcher("refund.jsp"); if (dispatcher != null){ dispatcher.forward(request, response); } } } and my jsp: jsp for displayng the values of the arraylist in a table.... i want to do the same thing but using ajax.... please help <html <body><table id= "table" border="0" width="303"> <tr> <td width="250"><b>Your Policy Refund Details is:</b></td> </tr> <%Iterator itr; %> <% ArrayList refund= (ArrayList)request.getAttribute("data"); if(refund != null){ for(itr=refund.iterator(); itr.hasNext();){ %> <tr> <td><%=itr.next()%></td> </tr> <%}}%> </table> </body> </html> how can i display this arraylist values using ajax??? please help

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  • Index an array expression directly in PostgreSQL

    - by wich
    I'm trying to insert data into a table from a template table. I need to rewrite one of the columns for which I wanted to use a directly indexed array expression, but I can't seem to find how to do this, if it is even possible. The scenario: create table template ( id integer, index integer, foo integer); insert into template values (0, 1, 23), (0, 2, 18), (0, 3, 16), (0, 4, 7), (1, 1, 17), (1, 2, 26), (1, 3, 11), (1, 4, 3); create table data ( data_id integer, foo integer); Now what I'd like to do is the following: insert into data select (array[3,7,5,2])[index], foo from template where id = 1; But this doesn't work, the (array[3,7,5,2])[index] syntax isn't valid. I tried a few variants, but was unable to get anything working and wasn't able to find the correct syntax in the docs, nor even whether this is at all possible or not. As a current workaround I've devised the following, but it is less than ideal, from an elegance perspective at least, but it may also be a performance hit, I haven't looked into that yet. insert into data select arr[index], foo from template, (select array[3,7,5,2] as arr) as q where id = 1; If anyone could suggest a (better) alternative to accomplish this I'd like to hear that as well.

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  • Make interchangeable class types via pointer casting only, without having to allocate any new objects?

    - by HostileFork
    UPDATE: I do appreciate "don't want that, want this instead" suggestions. They are useful, especially when provided in context of the motivating scenario. Still...regardless of goodness/badness, I've become curious to find a hard-and-fast "yes that can be done legally in C++11" vs "no it is not possible to do something like that". I want to "alias" an object pointer as another type, for the sole purpose of adding some helper methods. The alias cannot add data members to the underlying class (in fact, the more I can prevent that from happening the better!) All aliases are equally applicable to any object of this type...it's just helpful if the type system can hint which alias is likely the most appropriate. There should be no information about any specific alias that is ever encoded in the underlying object. Hence, I feel like you should be able to "cheat" the type system and just let it be an annotation...checked at compile time, but ultimately irrelevant to the runtime casting. Something along these lines: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Under the hood, the factory method is actually making a NodeBase class, and then using a similar reinterpret_cast to return it as a Node<AccessorFoo>*. The easy way to avoid this is to make these lightweight classes that wrap nodes and are passed around by value. Thus you don't need casting, just Accessor classes that take the node handle to wrap in their constructor: AccessorFoo foo (NodeBase::createViaFactory()); AccessorBar bar (foo.getNode()); But if I don't have to pay for all that, I don't want to. That would involve--for instance--making a special accessor type for each sort of wrapped pointer (AccessorFooShared, AccessorFooUnique, AccessorFooWeak, etc.) Having these typed pointers being aliased for one single pointer-based object identity is preferable, and provides a nice orthogonality. So back to that original question: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Seems like there would be some way to do this that might be ugly but not "break the rules". According to ISO14882:2011(e) 5.2.10-7: An object pointer can be explicitly converted to an object pointer of a different type.70 When a prvalue v of type "pointer to T1" is converted to the type "pointer to cv T2", the result is static_cast(static_cast(v)) if both T1 and T2 are standard-layout types (3.9) and the alignment requirements of T2 are no stricter than those of T1, or if either type is void. Converting a prvalue of type "pointer to T1" to the type "pointer to T2" (where T1 and T2 are object types and where the alignment requirements of T2 are no stricter than those of T1) and back to its original type yields the original pointer value. The result of any other such pointer conversion is unspecified. Drilling into the definition of a "standard-layout class", we find: has no non-static data members of type non-standard-layout-class (or array of such types) or reference, and has no virtual functions (10.3) and no virtual base classes (10.1), and has the same access control (clause 11) for all non-static data members, and has no non-standard-layout base classes, and either has no non-static data member in the most-derived class and at most one base class with non-static data members, or has no base classes with non-static data members, and has no base classes of the same type as the first non-static data member. Sounds like working with something like this would tie my hands a bit with no virtual methods in the accessors or the node. Yet C++11 apparently has std::is_standard_layout to keep things checked. Can this be done safely? Appears to work in gcc-4.7, but I'd like to be sure I'm not invoking undefined behavior.

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  • Efficient way to store order in mySQL for list of items

    - by ninumedia
    I want to code cleaner and more efficiently and I wanted to know any other suggestions for the following problem: I have a mySQL database that holds data about a set of photograph names. Oh, say 100 photograph names Table 1: (photos) has the following fields: photo_id, photo_name Ex data: 1 | sunshine.jpg 2 | cloudy.jpg 3 | rainy.jpg 4 | hazy.jpg ... Table 2: (categories) has the following fields: category_id, category_name, category_order Ex data: 1 | Summer Shots | 1,2,4 2 | Winter Shots | 2,3 3 | All Seasons | 1,2,3,4 ... Is it efficient to store the order of the photos in this manner per entry via comma delimited values? It's one approach I have seen used before but I wanted to know if something else is faster in run time. Using this way I don't think it is possible to do a direct INNER JOIN on the category table and photo table to get a single matched list of all the photographs per category. Ex: Summer shots - sunshine.jpg, cloudy.jpg, hazy.jpg because it was matched against 1,2,4 The iteration through all the categories and then the photos will have a O(n^2) and there has to be a better/faster way. Please educate me :)

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  • Logic for rate approximation

    - by Rohan
    I am looking for some logic to solve the below problem. There are n transaction amounts : T1,T2,T3.. Tn. Commission for these transactions are calculated using a rate table provided as below. if amount between 0 and A1 - rate is r1 if amount between A1 and A2 - rate is r2 if amount between A2 and A1 - rate is r3 ... ... if amount greater than An - rate is r4 So if T1 < A1 then rate table returns r1 else if r1 < T1 < r2;it returns r2. So,lets says the rate table results for T1,T2 and T3 are r1,r2 and r3 respectively. Commission C = T1 * r1 + T2 * r2 + T3 * r3 e.g; if rate table is defined(rates are in %) 0 - 2500 - 1 2501 - 5000 - 2 5001 - 10000 - 4 10000 or more- 6 If T1 = 6000,T2 = 3000, T3 = 2000, then C= 6000 * 0.04 + 3000* 0.02 + 2000 * 0.01 = 320 Now my problem is whether we can approximate the commission amount if instead of individual values of T1,T2 and T3 we are provided with T1+T2+T3 (T) In the above example if T (11000) is applied to the rate tablewe would get 6% and which would result in a commision of 600. Is there a way to approximate the commission value given T instead of individual values of T1,T2,T3?

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  • how to make changes to database in WPF?

    - by user353573
    Drag access database into designer xsd, toolkit:datagrid get datacontext from resources correctly show the table content through this binding. Press button in the button column, can show each row correctly. delete row and add row also work in datagrid however, when i press button column to add a new row or delete a row, there is no change in the underlying database, how to commit the changes from datagrid to database in WPF if not using ADO.net ? The following code is what i try do not work private void datagrid2_delete(object sender, RoutedEventArgs e) { Button showButton = (Button)sender; //person p = (person)showButton.DataContext; DataRowView ds = (DataRowView)showButton.DataContext; //DataSet1.customertableRow p = (DataSet1.customertableRow)ds; //ds.BeginEdit(); //ds.Delete(); //ds.EndEdit(); /* DataSourceProvider provider = (DataSourceProvider)this.FindResource("Family"); WpfApplication1.DataSet1.customertableDataTable table = (WpfApplication1.DataSet1.customertableDataTable)provider.Data; table.AddcustomertableRow("hello3", 5, System.DateTime.Today); table.AcceptChanges(); }

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  • Positioning DIV element at center of screen

    - by iSumitG
    I want to position a DIV (or a TABLE) element at the center of screen irrespective of screen size. In other words, the space left on 'top' and 'bottom' should be equal and space left on 'right' and 'left' sides should be equal. How to do it? Note: I prefer a complete CSS solution, but if is not possible without Javascript then using Javascript is also fine. I am trying the following but it is not working: <body> <div style="top:0px; border:1px solid red;"> <table border="1" align="center"> <tr height="100%"> <td height="100%" width="100%" valign="middle" align="center"> We are launching soon! </td> </tr> </table> </div> </body> Note: It is either way fine if the DIV element (or TABLE) scrolls with the website or not. Just want it to be at center when page loads.

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  • What should i do for accomodating large scale data storage and retrieval?

    - by kailashbuki
    There's two columns in the table inside mysql database. First column contains the fingerprint while the second one contains the list of documents which have that fingerprint. It's much like an inverted index built by search engines. An instance of a record inside the table is shown below; 34 "doc1, doc2, doc45" The number of fingerprints is very large(can range up to trillions). There are basically following operations in the database: inserting/updating the record & retrieving the record accoring to the match in fingerprint. The table definition python snippet is: self.cursor.execute("CREATE TABLE IF NOT EXISTS `fingerprint` (fp BIGINT, documents TEXT)") And the snippet for insert/update operation is: if self.cursor.execute("UPDATE `fingerprint` SET documents=CONCAT(documents,%s) WHERE fp=%s",(","+newDocId, thisFP))== 0L: self.cursor.execute("INSERT INTO `fingerprint` VALUES (%s, %s)", (thisFP,newDocId)) The only bottleneck i have observed so far is the query time in mysql. My whole application is web based. So time is a critical factor. I have also thought of using cassandra but have less knowledge of it. Please suggest me a better way to tackle this problem.

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  • SQL SERVER FOR XML SYNTAX

    - by Raj73
    How can I get an output as follows using FOR XML / sql query. I am not sure how I can get the Column Values as Elements instead of the tables' column Names. I am using sql server 2005 I HAVE TABLE SCEMA AS FOLLOWS CREATE TABLE PARENT ( PID INT, PNAME VARCHAR(20) ) CREATE TABLE CHILD ( PID INT, CID INT, CNAME VARCHAR(20) ) CREATE TABLE CHILDVALUE ( CID INT, CVALUE VARCHAR(20) ) INSERT INTO PARENT VALUES (1, 'SALES1') INSERT INTO PARENT VALUES (2, 'SALES2') INSERT INTO CHILD VALUES (1, 1, 'FOR01') INSERT INTO CHILD VALUES (1, 2, 'FOR02') INSERT INTO CHILD VALUES (2, 3, 'FOR03') INSERT INTO CHILD VALUES (2, 4, 'FOR04') INSERT INTO CHILDVALUE VALUES (1, '250000') INSERT INTO CHILDVALUE VALUES (2, '400000') INSERT INTO CHILDVALUE VALUES (3, '500000') INSERT INTO CHILDVALUE VALUES (4, '800000') The Output I am looking for is as follows <SALE1> <FOR01>250000</FOR01> <FOR02>400000</FOR02> </SALE1> <SALE2> <FOR03>500000</FOR03> <FOR04>800000</FOR04> </SALE2>

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  • gridview image column problem

    - by jame
    Work on vs05 C# asp.net .My SQL Syntax is :**** if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[Images]') and OBJECTPROPERTY(id, N'IsUserTable') = 1) drop table [dbo].[Images] GO CREATE TABLE [dbo].[Images] ( [ID] [numeric](18, 0) IDENTITY (1, 1) NOT NULL , [ImageName] [varchar] (50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL , [Image] [image] NULL ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY] GO I want to show this Images table values in a grid view.....I do it ...but the image value can not show ....asp.net syntax for gridview is <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="False"> <Columns> <asp:BoundField DataField="ImageName" HeaderText="ImageName" /> <asp:TemplateField HeaderText="Image"> <EditItemTemplate> <asp:TextBox ID="TextBox1" runat="server" Text='<%# Eval("Image") %>'></asp:TextBox> </EditItemTemplate> <ItemTemplate> <asp:Image ID="Image1" runat="server" ImageUrl='<%# Eval("Image") %>' /> </ItemTemplate> </asp:TemplateField> </Columns> </asp:GridView> i write the below code on pageload event. i want images table values must shown when the page is load... string strSQL = "Select * From Images"; DataTable dt = clsDB.getDataTable(strSQL); this.GridView2.DataSource = dt; this.GridView2.DataBind(); Why not i get the image on my image column of the gridview.....what's the problem is how to solve?

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