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  • GridView will not update underlying data source

    - by John Christensen
    So I'm been pounding on this problem all day. I've got a LinqDataSource that points to my model and a GridView that consumes it. When I attempt to do an update on the GridView, it does not update the underlying data source. I thought it might have to do with the LinqDataSource, so I added a SqlDataSource and the same thing happens. The aspx is as follows (the code-behind page is empty): <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="Data Source=devsql32;Initial Catalog=Steam;Persist Security Info=True;" ProviderName="System.Data.SqlClient" SelectCommand="SELECT [LangID], [Code], [Name] FROM [Languages]" UpdateCommand="UPDATE [Languages] SET [Code]=@Code WHERE [LangID]=@LangId"> </asp:SqlDataSource> <asp:GridView ID="_languageGridView" runat="server" AllowPaging="True" AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="LangId" DataSourceID="SqlDataSource1"> <Columns> <asp:CommandField ShowDeleteButton="True" ShowEditButton="True" /> <asp:BoundField DataField="LangId" HeaderText="Id" ReadOnly="True" /> <asp:BoundField DataField="Code" HeaderText="Code" /> <asp:BoundField DataField="Name" HeaderText="Name" /> </Columns> </asp:GridView> <asp:LinqDataSource ID="_languageDataSource" ContextTypeName="GeneseeSurvey.SteamDatabaseDataContext" runat="server" TableName="Languages" EnableInsert="True" EnableUpdate="true" EnableDelete="true"> </asp:LinqDataSource> What in the world am I missing here? This problem is driving me insane.

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  • How to enumerate word document using office interop API?

    - by Shekhar
    Hello everyone, I want to traverse through all the elements of an word document one by one and according to type of element (header, sentence, table,image,textbox, shape, etc.) I want to process that element. I tried to search any enumerator or object which can represent elements of document in office interop API but failed to find any. API offers sentences, paragraphs, shapes collections but doesnt provide generic object which can point to next element. For example : <header of document> <plain text sentences> <table with many rows,columns> <text box> <image> <footer> (Please imagine it as a word document) So, now I want some enumerator which will first give me <header of document>, then on next iteration give me <plain text sentences>, then <table with many rows,columns> and so on. Does anyone knows how we can achieve this? Is it possible? I am using C#, visual studio 2005 and Word 2003. Thanks a lot

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  • Rails: creating a custom data type, to use with generator classes and a bunch of questions related t

    - by Shyam
    Hi, After being productive with Rails for some weeks, I learned some tricks and got some experience with the framework. About 10 days ago, I figured out it is possible to build a custom data type for migrations by adding some code in the Table definition. Also, after learning a bit about floating points (and how evil they are) vs integers, the money gem and other possible solutions, I decided I didn't WANT to use the money gem, but instead try to learn more about programming and finding a solution myself. Some suggestions said that I should be using integers, one for the whole numbers and one for the cents. When playing in script/console, I discovered how easy it is to work with calculations and arrays. But, I am talking to much (and the reason I am, is to give some sufficient background). Right now, while playing with the scaffold generator (yes, I use it, because I like they way I can quickly set up a prototype while I am still researching my objectives), I like to use a DRY method. In my opinion, I should build a custom "object", that can hold two variables (Fixnum), one for the whole, one for the cents. In my big dream, I would be able to do the following: script/generate scaffold Cake name:string description:text cost:mycustom Where mycustom should create two integer columns (one for wholes, one for cents). Right now I could do this by doing: script/generate scaffold Cake name:string description:text cost_w:integer cost_c:integer I had also had an idea that would be creating a "cost model", which would hold two columns of integers and create a cost_id column to my scaffold. But wouldn't that be an extra table that would cause some kind of performance penalty? And wouldn't that be defy the purpose of the Cake model in the first place, because the costs are an attribute of individual Cake entries? The reason why I would want to have such a functionality because I am thinking of having multiple "costs" inside my rails application. Thank you for your feedback, comments and answers! I hope my message got through as understandable, my apologies for incorrect grammar or weird sentences as English is not my native language.

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  • Problem with Active Record

    - by kshchepelin
    Hello everyone. Lets assume we have a User model. And user can plan some activities. The number of types of activities is about 50. All activities have common properties, such as start_time, end_time, user_id, etc. But each of them has some unique properties. Now we have each activity living in its own table in DB. And thats why we have such terrible sql queries like SELECT * FROM `first_activities_table` WHERE (`first_activity`.`id` IN (17,18)) SELECT * FROM `second_activities_table` WHERE (`second_activity`.`id` = 17) ..... SELECT * FROM `n_activities_table` WHERE (`n_activity`.`id` = 44) About 50 queries. That's terrible. There are different ways to solve this. Choose the activity type with the biggest number of properties, create the table 'Activities' and have STI model. But this way we must name our columns in uncomfortable way and often the record in that table would have some NULL fields. Also STI model, but having columns, common for all of activity types and some blob column with serialized properties. But we have to do some search on activities - there can be a problem. And serialization is quite slow. Please help me dealing with this. Maybe my problem has quite different solution that will fit my needs. Thanks for help.

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  • Translation of a RoR view to Java

    - by mnml
    Hi, for some reasons I am trying to translate the following RoR view code to a GSP view: List<Object> objectscontains the data I want to display in 3 columns <% modulo_objects = @objects.length % 3 base = @objects.length / 3 base = base.ceil case modulo_objects when 0 cols = [base, base, base] when 1 cols = [base, base + 1, base] when 2 cols = [base + 1, base, base + 1] end counter = 0 %> <% 3.times do |i| %> <td width="220" align="center" style="padding-right: 15px;"> <% cols[i].times do %> <h1><a href="/objects/show/<%= @objects[counter].urlname %>" ><%= @objects[counter].name %></a></h1> <% counter = counter + 1 %> <% end %> </td> <% end %> This is what I got so far: #{extends 'main.html' /} %{ modulo_objects = objects.size() % 3 base = objects.size() / 3 base = Math.ceil(base) if(modulo_objects == 0) cols = [base, base, base] else if(modulo_objects == 1) cols = [base, base + 1, base] else if(modulo_objects == 2) cols = [base + 1, base, base + 1] endif counter = 0 }% #{list items:1..3, as:'i'} <td width="220" align="center" style="padding-right: 15px;"> #{list items:cols[i]} <a href="@{Objects.show(objects.get(counter).name.replaceAll(" ", "-"))}" >${objects.get(counter).name}</a> %{ counter = counter + 1 }% #{/list} </td> #{/list} The idea is to keep the items organised in 3 columns like 1|0|1 4|5|4 or 5|4|5 for example, I don't really understand if #{list items:cols[i]} will reproduce ruby's cols[i].times do. So far the Java view is does not display more than two elements.

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  • Cursor returns zero rows from query to table

    - by brockoli
    I've created an SQLiteDatabase in my app and populated it with some data. I can connect to my AVD with a terminal and when I issue select * from articles; I get a list of all the rows in my table and everything looks fine. However, in my code when I query my table, I get a cursor back that has my tables columns, but zero rows of data. Here is my code.. mDbHelper.open(); Cursor articles = mDbHelper.fetchAllArticles(); startManagingCursor(articles); Cursor feeds = mDbHelper.fetchAllFeeds(); startManagingCursor(feeds); mDbHelper.close(); int titleColumn = articles.getColumnIndex("title"); int feedIdColumn = articles.getColumnIndex("feed_id"); int feedTitleColumn = feeds.getColumnIndex("title"); /* Check if our result was valid. */ if (articles != null) { int count = articles.getCount(); /* Check if at least one Result was returned. */ if (articles.moveToFirst()) { In the above code, my Cursor articles returns with my 4 columns, but when I call getCount() it returns zero, even though I can see hundreds of rows of data in that table from command line. Any idea what I might be doing wrong here? Also.. here is my code for fetchAllArticles.. public Cursor fetchAllArticles() { return mDb.query(ARTICLES_TABLE, new String[] {ARTICLE_KEY_ROWID, ARTICLE_KEY_FEED_ID, ARTICLE_KEY_TITLE, ARTICLE_KEY_URL}, null, null, null, null, null); } Rob W.

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  • Given an even number of vertices, how to find an optimum set of pairs based on proximity?

    - by Alex Z
    The problem: We have a set of n vertices in 3D euclidean space, and there is an even number of these vertices. We want to pair them up based on their proximity. In other words, we'd like to be able to find a set of vertex pairs, where the vertices in each pair are as close as possible together. We want to minimise sacrificing the proximity between the vertices of any other pairs as much as possible in doing this. I am not looking for the most optimal solution (if it even strictly exists/can be done), just a reasonable one that can be computed relatively quickly. A relatively awful brute force approach involves choosing a vertex and looping through the rest to find its nearest neighbor and then repeating until there are none left. Of course as we near the end of the list the closest vertex could be very far away, but it is the only choice, therefore this can fail badly on the third point above.

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  • ASP:GridView does not show data with ObjectdataSource

    - by Kashif
    I have been trying to bind a DataGrid with ObjectDataSource having custom paging but no output is display on my usercontrol. Here is the code I am using <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="LeadId" DataSourceID="dsBuyingLead1" AllowPaging="True"> <Columns> <asp:BoundField DataField="Subject" HeaderText="Subject" ReadOnly="True" /> <asp:BoundField DataField="ExpiryDate" HeaderText="ExpiryDate" ReadOnly="True" /> </Columns> </asp:GridView> <asp:ObjectDataSource ID="dsBuyingLead1" runat="server" EnablePaging="True" DataObjectTypeName="Modules.SearchBuyingLeadInfo" OldValuesParameterFormatString="original_{0}" SelectMethod="GetAllBuyingLeads" StartRowIndexParameterName="startRow" MaximumRowsParameterName="maximumRows" SelectCountMethod="GetAllBuyingLeadsCount" TypeName="Modules.SearchController"> <SelectParameters> <asp:QueryStringParameter Name="searchText" QueryStringField="q" Type="String" /> </SelectParameters> </asp:ObjectDataSource> Here are my methods from SearchController class: [DataObjectMethod(DataObjectMethodType.Select)] public static long GetAllBuyingLeadsCount(string searchText) { return DataProvider.Instance().GetAllBuyingLeadsCount(searchText); } [DataObjectMethod(DataObjectMethodType.Select)] public static List<SearchBuyingLeadInfo> GetAllBuyingLeads (string searchText, int startRow, int maximumRows) { List<SearchBuyingLeadInfo> l = CBO.FillCollection<SearchBuyingLeadInfo> ( DataProvider.Instance() .GetAllBuyingLeadswithText(searchText, startRow, maximumRows) ); return l; } Where SearchBuyingLeadInfo is my Data Access Object class I have verified by setting up break points that both GetAllBuyingLeadsCount and GetAllBuyingLeads return non-zero values but unfortunately nothing is displayed on the grid. Only the column headers are displayed. Can anyone tell me what am I missing?

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  • Inconsistent behavior working with "Flex on Rails" example.

    - by kmontgom
    I'm experimenting with Flex and Rails right now (Rails is cool). I'm following the examples in the book "Flex on Rails", and I'm getting some puzzling and inconsistent behavior. Heres the Flex MXML: <mx:HTTPService id="index" url="http://localhost:3000/people.xml" resultFormat="e4x" /> <mx:DataGrid dataProvider="{index.lastResult.person}" width="100%" height="100%"> <mx:columns> <mx:DataGridColumn headerText="First Name" dataField="first-name"/> <mx:DataGridColumn headerText="Last Name" dataField="last-name"/> </mx:columns> </mx:DataGrid> <mx:Script> <![CDATA[ import mx.controls.Alert; private function main():void { Alert.show( "In main()" ); } ]]> </mx:Script> When I run the app from my IDE (Amythyst beta, also cool), the DataGrid appears, but is not populated. The Alert.show() also triggers. When I go out to a web browser and manually enter the url (http://localhost:3000/people.xml), the Mongrel console shows the request coming through and the browser shows the web response. No exceptions or other error messages occur. Whats the difference? Do I need to alter some OS setting? I'm using Win7 on an x64 machine.

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  • Conditional column values in NSTableView?

    - by velocityb0y
    I have an NSTableView that binds via an NSArrayController to an NSMutableArray. What's in the array are derived classes; the first few columns of the table are bound to properties that exist on the base class. That all works fine. Where I'm running into problem is a column that should only be populated if the row maps to one specific subclass. The property that column is meant to display only exists in that subclass, since it makes no sense in terms of the base class. The user will know, from the first two columns, why the third column's cell is populated/editable or not. The binding on the third column's value is on arrangedObjects, with a model path of something like "foo.name" where foo is the property on the subclass. However, this doesn't work, as the other subclasses in the hierarchy are not key-value compliant for foo. It seems like my only choice is to have foo be a property on the base class so everybody responds to it, but this clutters up the interfaces of the model objects. Has anyone come up with a clean design for this situation? It can't be uncommon (I'm a relative newcomer to Cocoa and I'm just learning the ins and outs of bindings.)

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  • Parsing multiple files at a time in Perl

    - by sfactor
    I have a large data set (around 90GB) to work with. There are data files (tab delimited) for each hour of each day and I need to perform operations in the entire data set. For example, get the share of OSes which are given in one of the columns. I tried merging all the files into one huge file and performing the simple count operation but it was simply too huge for the server memory. So, I guess I need to perform the operation each file at a time and then add up in the end. I am new to perl and am especially naive about the performance issues. How do I do such operations in a case like this. As an example two columns of the file are. ID OS 1 Windows 2 Linux 3 Windows 4 Windows Lets do something simple, counting the share of the OSes in the data set. So, each .txt file has millions of these lines and there are many such files. What would be the most efficient way to operate on the entire files.

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  • SQLAlchemy & Complex Queries

    - by user356594
    I have to implement ACL for an existing application. So I added the a user, group and groupmembers table to the database. I defined a ManyToMany relationship between user and group via the association table groupmembers. In order to protect some ressources of the app (i..e item) I added a additional association table auth_items which should be used as an association table for the ManyToMany relationship between groups/users and the specific item. item has following columns: user_id -- user table group_id -- group table item_id -- item table at least on of user_id and group_id columns are set. So it's possible to define access for a group or for a user to a specific item. I have used the AssociationProxy to define the relationship between users/groups and items. I now want to display all items which the user has access to and I have a really hard time doing that. Following criteria are used: All items which are owned by the user should be shown (item.owner_id = user.id) All public items should be shown (item.access = public) All items which the user has access to should be shown (auth_item.user_id = user.id) All items which the group of the user has access to should be shown. The first two criteria are quite straightforward, but I have a hard time doing the 3rd one. Here is my approach: clause = and_(item.access == 'public') if user is not None: clause = or_(clause,item.owner == user,item.users.contains(user),item.groups.contains(group for group in user.groups)) The third criteria produces an error. item.groups.contains(group for group in user.groups) I am actually not sure if this is a good approach at all. What is the best approach when filtering manytomany relationships? How I can filter a manytomany relationship based on another list/relationship? Btw I am using the latest sqlalchemy (6.0) and elixir version Thanks for any insights.

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  • Correct formulation of the A* algorithm

    - by Eli Bendersky
    Hello, I'm looking at definitions of the A* path-finding algorithm, and it seems to be defined somewhat differently in different places. The difference is in the action performed when going through the successors of a node, and finding that a successor is on the closed list. One approach (suggested by Wikipedia, and this article) says: if the successor is on the closed list, just ignore it Another approach (suggested here and here, for example) says: if the successor is on the closed list, examine its cost. If it's higher than the currently computed score, remove the item from the closed list for future examination. I'm confused - which method is correct ? Intuitively, the first makes more sense to me, but I wonder about the difference in definition. Is one of the definitions wrong, or are they somehow isomorphic ?

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  • how to place dropdown list box in jquery grid column

    - by kumar
    Hello friends, I have a jquery grid columns defined like this.. using System; using System.Collections.Generic; using System.Linq; using System.Web; using Trirand.Web.Mvc; using System.Web.UI.WebControls; namespace JQGridMVCExamples.Models { public class OrdersJqGridModel { public OrdersJqGridModel() { OrdersGrid = new JQGrid { Columns = new List<JQGridColumn>() { new JQGridColumn { DataField = "OrderID", Width = 50 }, new JQGridColumn { DataField = "OrderDate", Width = 100, DataFormatString = "{0:d}" }, new JQGridColumn { DataField = "CustomerID", Width = 100 }, new JQGridColumn { DataField = "Freight", Width = 75 }, new JQGridColumn { DataField = "ShipName" } }, Width = Unit.Pixel(640) }; OrdersGrid.ToolBarSettings.ShowRefreshButton = true; } public JQGrid OrdersGrid { get; set; } } } and in the view I am caling like this <div> <%= Html.Trirand().JQGrid(Model.OrdersGrid, "JQGrid1") %> </div> I am getting result perfect.. but for column Freight in the Jquery grid I need to place a dropdown list dynamically for all result rows.. can anyone help me out.. THanks

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  • Unable to set row height for grid view

    - by GabrielHeng
    I tried to set a row height for each row of my grid view in visual studio. However, it does not work. The row height will not change according to the pixel that I typed in. Here is my codes. <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AutoGenerateColumns="False" DataKeyNames="productID" DataSourceID="SqlDataSource1" BackColor="White" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" CellPadding="4" ForeColor="Black" GridLines="Horizontal" Width = "850px" style="margin-bottom: 6px" RowStyle-Height="50px"> <AlternatingRowStyle Height="50px" /> <Columns> <asp:CommandField ButtonType="Button" ShowDeleteButton="True" ShowEditButton="True" /> <asp:BoundField DataField="productID" HeaderText="ProductID" ReadOnly="True" SortExpression="productID" /> <asp:BoundField DataField="title" HeaderText="Title" SortExpression="title" /> <asp:BoundField DataField="description" HeaderText="Description" SortExpression="description" /> <asp:BoundField DataField="price" HeaderText="Price" SortExpression="price" /> <asp:ImageField DataImageUrlField="image" HeaderText="Images" SortExpression="image" DataImageUrlFormatString="~/images/{0}"> </asp:ImageField> </Columns> <FooterStyle BackColor="#CCCC99" ForeColor="Black" /> <HeaderStyle BackColor="#333333" Font-Bold="True" ForeColor="White" /> <PagerStyle BackColor="White" ForeColor="Black" HorizontalAlign="Right" /> <SelectedRowStyle BackColor="#CC3333" Font-Bold="True" ForeColor="White" /> <SortedAscendingCellStyle BackColor="#F7F7F7" /> <SortedAscendingHeaderStyle BackColor="#4B4B4B" /> <SortedDescendingCellStyle BackColor="#E5E5E5" /> <SortedDescendingHeaderStyle BackColor="#242121" /> </asp:GridView> May someone help me with it? Thanks in advance.

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  • Hibernate does not allow an embedded object with an int field to be null?

    - by Jason Novak
    Hibernate does not allow me to persist an object that contains an null embedded object with an integer field. For example, if I have a class called Thing that looks like this @Entity public class Thing { @Id public String id; public Part part; } where Part is an embeddable class that looks like this @Embeddable public class Part { public String a; public int b; } then trying to persist a Thing object with a null Part causes Hibernate to throw an Exception. In particular, this code Thing th = new Thing(); th.id = "thing.1"; th.part = null; session.saveOrUpdate(th); causes Hibernate to throw this Exception org.hibernate.PropertyValueException: not-null property references a null or transient value: com.ace.moab.api.jobs.Thing.part My guess is that this is happening because Part is an embedded class and so Part.a and Part.b are simply columns in the Thing database table. Since the Thing.part is null Hibernate wants to set the Part.a and Part.b column values to null for the row for thing.1. However, Part.b is an integer and Hibernate will not allow integer columns in the database to be null. This is what causes the Exception, right? So I am looking for workarounds for this problem. I noticed making Part.b an Integer instead of an int seems to work, but for reasons I won't bore you with this is not a good option for us. Thanks!

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  • Database localization

    - by Don
    Hi, I have a number of database tables that contain name and description columns which need to be localized. My initial attempt at designing a DB schema that would support this was something like: product ------- id name description local_product ------- id product_id local_name local_description locale_id locale ------ id locale However, this solution requires a new local_ table for every table that contains name and description columns that require localization. In an attempt to avoid this overhead I redesigned the schema so that only a single localization table is needed product ------- id localization_id localization ------- id local_name local_description locale_id locale ------ id locale Here's an example of the data which would be stored in this schema when there are 2 tables (product and country) requiring localization: country id, localization_id ----------------------- 1, 5 product id, localization_id ----------------------- 1, 2 localization id, local_name, local_description, locale_id ------------------------------------------------------ 2, apple, a delicious fruit, 2 2, pomme, un fruit délicieux, 3 2, apfel, ein köstliches Obst, 4 5, ireland, a small country, 2 5, irlande, un petite pay, 3 locale id, locale -------------- 2, en 3, fr 4, de Notice that the compound primary key of the localization table is (id, locale_id), but the foreign key in the product table only refers to the first element of this compound PK. This seems like 'a bad thing' from the POV of normalization. Is there any way I can fix this problem, or alternatively, is there a completely different schema that supports localization without creating a separate table for each localizable table? Update: A number of respondents have proposed a solution that requires creating a separate table for each localizable table. However, this is precisely what I'm trying to avoid. The schema I've proposed above almost solves the problem to my satisfaction, but I'm unhappy about the fact that the localization_id foreign keys only refer to part of the corresponding primary key in the localization table. Thanks, Don

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  • Get a CSS value from external style sheet with Javascript/jQuery

    - by Acorn
    Is it possible to get a value from the external CSS of a page if the element that the style refers to has not been generated yet? (the element is to be generated dynamically). The jQuery method I've seen is $('element').css('property','value');, but this relies on element being on the page. Is there a way of finding out what the property is set to within the CSS rather than the computed style of an element? Will I have to do something ugly like add a hidden copy of the element to my page so that I can access its style attributes?

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  • MySQL SELECT combining 3 SELECTs INTO 1

    - by Martin Tóth
    Consider following tables in MySQL database: entries: creator_id INT entry TEXT is_expired BOOL other: creator_id INT entry TEXT userdata: creator_id INT name VARCHAR etc... In entries and other, there can be multiple entries by 1 creator. userdata table is read only for me (placed in other database). I'd like to achieve a following SELECT result: +------------+---------+---------+-------+ | creator_id | entries | expired | other | +------------+---------+---------+-------+ | 10951 | 59 | 55 | 39 | | 70887 | 41 | 34 | 108 | | 88309 | 38 | 20 | 102 | | 94732 | 0 | 0 | 86 | ... where entries is equal to SELECT COUNT(entry) FROM entries GROUP BY creator_id, expired is equal to SELECT COUNT(entry) FROM entries WHERE is_expired = 0 GROUP BY creator_id and other is equal to SELECT COUNT(entry) FROM other GROUP BY creator_id. I need this structure because after doing this SELECT, I need to look for user data in the "userdata" table, which I planned to do with INNER JOIN and select desired columns. I solved this problem with selecting "NULL" into column which does not apply for given SELECT: SELECT creator_id, COUNT(any_entry) as entries, COUNT(expired_entry) as expired, COUNT(other_entry) as other FROM ( SELECT creator_id, entry AS any_entry, NULL AS expired_entry, NULL AS other_enry FROM entries UNION SELECT creator_id, NULL AS any_entry, entry AS expired_entry, NULL AS other_enry FROM entries WHERE is_expired = 1 UNION SELECT creator_id, NULL AS any_entry, NULL AS expired_entry, entry AS other_enry FROM other ) AS tTemp GROUP BY creator_id ORDER BY entries DESC, expired DESC, other DESC ; I've left out the INNER JOIN and selecting other columns from userdata table on purpose (my question being about combining 3 SELECTs into 1). Is my idea valid? = Am I trying to use the right "construction" for this? Are these kind of SELECTs possible without creating an "empty" column? (some kind of JOIN) Should I do it "outside the DB": make 3 SELECTs, make some order in it (let's say python lists/dicts) and then do the additional SELECTs for userdata? Solution for a similar question does not return rows where entries and expired are 0. Thank you for your time.

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  • Doing arithmetic with up to two decimal places in Python?

    - by user248237
    I have two floats in Python that I'd like to subtract, i.e. v1 = float(value1) v2 = float(value2) diff = v1 - v2 I want "diff" to be computed up to two decimal places, that is compute it using %.2f of v1 and %.2f of v2. How can I do this? I know how to print v1 and v2 up to two decimals, but not how to do arithmetic like that. The particular issue I am trying to avoid is this. Suppose that: v1 = 0.982769777778 v2 = 0.985980444444 diff = v1 - v2 and then I print to file the following: myfile.write("%.2f\t%.2f\t%.2f\n" %(v1, v2, diff)) then I will get the output: 0.98 0.99 0.00, suggesting that there's no difference between v1 and v2, even though the printed result suggests there's a 0.01 difference. How can I get around this? thanks.

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  • Calculating and saving space in Postgresql

    - by punkish
    I have a table in Pg like so CREATE TABLE t ( a BIGSERIAL NOT NULL, -- 8 b b SMALLINT, -- 2 b c SMALLINT, -- 2 b d REAL, -- 4 b e REAL, -- 4 b f REAL, -- 4 b g INTEGER, -- 4 b h REAL, -- 4 b i REAL, -- 4 b j SMALLINT, -- 2 b k INTEGER, -- 4 b l INTEGER, -- 4 b m REAL, -- 4 b CONSTRAINT a_pkey PRIMARY KEY (a) ) The above adds up to 50 bytes per row. My experience is that I need another 40% to 50% for system overhead, without even any user-created indexes to the above. So, about 75 bytes per row. I will have many, many rows in the table, potentially upward of 145 billion rows, so the table is going to be pushing 13-14 Terabytes. What tricks, if any, could I use to compact this table? My possible ideas below -- Convert the REAL values to INTEGERs. If they can stored as SMALLINT, that is a saving of 2 bytes per field. Convert the columns b .. m into an array. I don't need to search on those columns, but I do need to be able to return one column's value at a time. So, if I need column g, I could do something like SELECT a, arr[5] FROM t; Would I save space with the array option? Would there be a speed penalty? Any other ideas?

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  • How to delete duplicate/aggregate rows faster in a file using Java (no DB)

    - by S. Singh
    I have a 2GB big text file, it has 5 columns delimited by tab. A row will be called duplicate only if 4 out of 5 columns matches. Right now, I am doing dduping by first loading each coloumn in separate List , then iterating through lists, deleting the duplicate rows as it encountered and aggregating. The problem: it is taking more than 20 hours to process one file. I have 25 such files to process. Can anyone please share their experience, how they would go about doing such dduping? This dduping will be a throw away code. So, I was looking for some quick/dirty solution, to get job done as soon as possible. Here is my pseudo code (roughly) Iterate over the rows i=current_row_no. Iterate over the row no. i+1 to last_row if(col1 matches //find duplicate && col2 matches && col3 matches && col4 matches) { col5List.set(i,get col5); //aggregate } Duplicate example A and B will be duplicate A=(1,1,1,1,1), B=(1,1,1,1,2), C=(2,1,1,1,1) and output would be A=(1,1,1,1,1+2) C=(2,1,1,1,1) [notice that B has been kicked out]

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  • Select statement with multiple 'where' fields using same value without duplicating text

    - by kdbdallas
    I will start by saying that I don't think what I want can be done, but that said, I am hoping I am wrong and someone knows more than me. So here is your chance... Prove you are smarter than me :) I want to do a search against a SQLite table looking for any records that "are similar" without having to write out the query in long hand. To clarify this is how I know I can write the query: select * from Articles where title like '%Bla%' or category like '%Bla%' or post like '%Bla%' This works and is not a huge deal if you are only checking against a couple of columns, but if you need to check against a bunch then your query can get really long and nasty looking really fast, not to mention the chance for typos. (ie: 'Bla%' instead of '%Bla%') What I am wondering is if there is a short hand way to do this? *This next code does not work the way I want, but just shows kind of what I am looking for select * from Articles where title or category or post like '%Bla%' Anyone know if there is a way to specify that multiple 'where' columns should use the same search value without listing that same search value for every column? Thanks in advance!

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  • MSSQL: Views that use SELECT * need to be recreated if the underlying table changes

    - by cbp
    Is there a way to make views that use SELECT * stay in sync with the underlying table. What I have discovered is that if changes are made to the underlying table, from which all columns are to be selected, the view needs to be 'recreated'. This can be achieved simly by running an ALTER VIEW statement. However this can lead to some pretty dangerous situations. If you forgot to recreate the view, it will not be returning the correct data. In fact it can be returning seriously messed up data - with the names of the columns all wrong and out of order. Nothing will pick up that the view is wrong unless you happened to have it covered by a test, or a data integrity check fails. For example, Red Gate SQL Compare doesn't pick up the fact that the view needs to be recreated. To replicate the problem, try these statements: CREATE TABLE Foobar (Bar varchar(20)) CREATE VIEW v_Foobar AS SELECT * FROM Foobar INSERT INTO Foobar (Bar) VALUES ('Hi there') SELECT * FROM v_Foobar ALTER TABLE Foobar ADD Baz varchar(20) SELECT * FROM v_Foobar DROP VIEW v_Foobar DROP TABLE Foobar I am tempted to stop using SELECT * in views, which will be a PITA. Is there a setting somewhere perhaps that could fix this behaviour?

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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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