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  • What is the Best way to databind an ASP.NET TreeView for table with many to many parent child relati

    - by Matt W
    I've got a table which has the usual ParentID, ChildID as it's first two columns in a self-referencing tree data structure. My issue is that when I pull this out and use the following code: DataSet set = DA.GetNewCategories(); set.Relations.Add( new DataRelation("parentChildCategories", set.Tables[0].Columns["CategoryParentID"], set.Tables[0].Columns["CategoryID"]) ); StringBuilder buildXml = new StringBuilder(); StringWriter writer = new StringWriter(buildXml); set.WriteXml(writer); TreeView2.DataSource = new HierarchicalDataSet(set, "CategoryID", "CategoryParentID"); TreeView2.DataBind(); I get the error: These columns don't currently have unique values I believe this is because my data has children with multiple parent nodes. This is fine for my application - I don't mind if one row of data is rendered in multiple nodes of my TreeView. Could someone shed light on this please? It doesn't seem unreasonable to have a DataSet render XML which has nodes appearing in multiple places, but I can't figure out how to do it. Thanks, Matt.

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  • Subsonic - How to use SQL Schema / Owner name as part of the namespace?

    - by CResults
    Hi there, I've just started using Subsonic 2.2 and so far very impressed - think it'll save me some serious coding time. Before I dive into using it full time though there is something bugging me that I'd like to sort out. In my current database (a SQL2008 db) I have split the tables, views, sps etc. up into separate chunks by schema/owner name, so all the customer tables are in the customer. schema, products in the product. schema etc., so a to select from the customers address table i'd do a select * from customer.address Unfortunately, Subsonic ignores the schema/owner name and just gives me the base table name. This is fine as I've no duplicates between schemas (e.g Customer.Address and Supplier.Address don't both exist) but I just feel the code could be clearer if I could split by schema. Ideally I'd like to be able to alter the namespace by schema/owner - I think this would have least impact on SubSonic yet make the resulting code easier to read. Problem is, I've crawled all over the Subsonic source and don't have a clue how to do this (doesn't help that I code in VB not C# = yes I know, blame the ZX Spectrum!!) If anyone has tackled this before or has an idea on how to solve it, I'd be really grateful, Thanks in advance. Ed

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  • Setting article properties for a publication using RMO in C# .NET

    - by Pavan Kumar
    I am using transaction replication with push subscription. I am developing a UI for replication using RMO in C#.NET between different instances of the same database within same machine holding similar schema and structure. I am using Single subscriber and multiple publisher topology. During creation of publication i want to set a few article properties such as Keep the existing object unchanged ,allow schema changes at subscriber to false a,copy foriegn key constarint and copy check constraints to true. How do i set the article properties using RMO in C# .NET. I am using Visual Studio 2008 SP1.I also want to know as how we can select all the objects including Tables,Views,Stored Procedures for publishing at one stretch. I could do it for one table but i want to select all the tables at one stretch. This is the code snippet i used for selecting single table for publishing. TransArticle ta = new TransArticle(); ta.Name = "Article_1"; ta.PublicationName = "TransReplication_DB2"; ta.DatabaseName = "DB2"; ta.SourceObjectName = "person"; ta.SourceObjectOwner = "dbo"; ta.ConnectionContext = conn; ta.Create();

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  • Reporting System architecture for better performance

    - by pauloya
    Hi, We have a product that runs Sql Server Express 2005 and uses mainly ASP.NET. The database has around 200 tables, with a few (4 or 5) that can grow from 300 to 5000 rows per day and keep a history of 5 years, so they can grow to have 10 million rows. We have built a reporting platform, that allows customers to build reports based on templates, fields and filters. We face performance problems almost since the beginning, we try to keep reports display under 10 seconds but some of them go up to 25 seconds (specially on those customers with long history). We keep checking indexes and trying to improve the queries but we get the feeling that there's only so much we can do. Off course the fact that the queries are generated dynamically doesn't help with the optimization. We also added a few tables that keep redundant data, but then we have the added problem of maintaining this data up to date, and also Sql Express has a limit on the size of databases. We are now facing a point where we have to decide if we want to give up real time reports, or maybe cut the history to be able to have better performance. I would like to ask what is the recommended approach for this kind of systems. Also, should we start looking for third party tools/platforms? I know OLAP can be an option but can we make it work on Sql Server Express, or at least with a license that is cheap enough to distribute to thousands of deployments? Thanks

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  • edmx - The operation could not be completed - After adding Inheritance

    - by vdh_ant
    Hey guys I have an edmx model which I have draged 2 tables onto - One called 'File' and the other 'ApplicaitonFile'. These two tables have a 1 to 1 relationship in the database. If I stop here everything works fine. But in my model, I want 'ApplicaitonFile' to inherit from 'File'. So I delete the 1 to 1 relationship then configure 'ApplicaitonFile' from 'File' and then remove the FileId from 'ApplicaitonFile' which was the primary key. (Note I am following the instructions from here). If I leave the model open at this point everything is fine, but as soon as I close it, if I try and reopen it again I get the following error "The operation could not be completed". I have been searching for a solution and found this - http://stackoverflow.com/questions/944050/entity-model-does-not-load but as far as I can tell I don't have a duplicate InheritanceConnectors (although I don't know exactly what I'm looking for but I can't see anything out of the ordinary - like 2 connectors with the same name) and the relationship I originally have is a 1 to 1 not a 1 to 0..1 Any ideas???

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  • rails, mysql charsets & encoding: binary

    - by Benjamin Vetter
    Hi, i've a rails app that runs using utf-8. It uses a mysql database, all tables with mysql's default charset and collation (i.e. latin1). Therefore the latin1 tables contain utf-8 data. Sure, that's not nice, but i'm not really interested in it. Everything works fine, because the connection encoding is latin1 as well and therefore mysql does not convert between charsets. Only one problem: i need a utf-8 fulltext index for one table: mysql> show create table autocompletephrases; ... AUTO_INCREMENT=310095 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci But: I don't want to convert between charsets in my rails app. Therefore I would like to know if i could just set config/database.yml production: adapter: mysql >>>> encoding: binary ... which just calls SET NAMES 'binary' when connecting to mySQL. It looks like it works for my case, because i guess it forces mysql to -not- convert between charsets (mySQL docs). Does anyone knows about problems about doing this? Any side-effects? Or do you have any other suggestions? But i'd like to avoid converting my whole database to utf-8. Many Thanks! Benjamin

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  • mysql database normalization question

    - by Chocho
    here is my 3 tables: table 1 -- stores user information and it has unique data table 2 -- stores place category such as, toronto, ny, london, etc hence this is is also unique table 3 -- has duplicate information. it stores all the places a user have been. the 3 tables are linked or joined by these ids: table 1 has an "table1_id" table 2 has an "table2_id" and "place_name" table 3 has an "table3_id", "table1_id", "place_name" i have an interface where an admin sees all users. beside a user is "edit" button. clicking on that edit button allows you to edit a specific user in a form fields which has a multiple drop down box for "places". if an admin edits a user and add 1 "places" for the user, i insert that information using php. if the admin decides to deselect that 1 "places" do i delete it or mark it as on and off? how about if the admin decides to select 2 "places" for the user; change the first "places" and add an additional "places". will my table just keep growing and will i have just redundant information? thanks.

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  • Taking the data mapper approach in Zend Framework

    - by Seeker
    Let's assume the following tables setup for a Zend Framework app. user (id) groups (id) groups_users (id, user_id, group_id, join_date) I took the Data Mapper approach to models which basically gives me: Model_User, Model_UsersMapper, Model_DbTable_Users Model_Group, Model_GroupsMapper, Model_DbTable_Groups Model_GroupUser, Model_GroupsUsersMapper, Model_DbTable_GroupsUsers (for holding the relationships which can be seen as aentities; notice the "join_date" property) I'm defining the _referenceMap in Model_DbTable_GroupsUsers: protected $_referenceMap = array ( 'User' => array ( 'columns' => array('user_id'), 'refTableClass' => 'Model_DbTable_Users', 'refColumns' => array('id') ), 'App' => array ( 'columns' => array('group_id'), 'refTableClass' => 'Model_DbTable_Groups', 'refColumns' => array('id') ) ); I'm having these design problems in mind: 1) The Model_Group only mirrors the fields in the groups table. How can I return a collection of groups a user is a member of and also the date the user joined that group for every group? If I just added the property to the domain object, then I'd have to let the group mapper know about it, wouldn't I? 2) Let's say I need to fetch the groups a user belongs to. Where should I put this logic? Model_UsersMapper or Model_GroupsUsersMapper? I also want to make use of the referencing map (dependent tables) mechanism and probably use findManyToManyRowset or findDependentRowset, something like: $result = $this->getDbTable()->find($userId); $row = $result->current(); $groups = $row->findManyToManyRowset( 'Model_DbTable_Groups', 'Model_DbTable_GroupsUsers' ); This would produce two queries when I could have just written it in a single query. I will place this in the Model_GroupsUsersMapper class. An enhancement would be to add a getGroups method to the Model_User domain object which lazily loads the groups when needed by calling the appropriate method in the data mapper, which begs for the second question. Should I allow the domain object know about the data mapper?

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  • LINQ-To-SQL and Mapping Table Deletions

    - by Jake
    I have a many-to-many relationship between two tables, let's say Friends and Foods. If a friend likes a food I stick a row into the FriendsFoods table, like this: ID Friend Food 1 'Tom' 'Pizza' FriendsFoods has a Primary Key 'ID', and two non-null foreign keys 'Friend' and 'Food' to the 'Friends' and 'Foods' tables, respectively. Now suppose I have a Friend tom .NET object corresponding to 'Tom', and Tom no longer likes pizza (what is wrong with him?) FriendsFoods ff = tblFriendsFoods.Where(x => x.Friend.Name == 'Tom' && x.Food.Name == 'Pizza').Single(); tom.FriendsFoods.Remove(ff); pizza.FriendsFoods.Remove(ff); If I try to SubmitChanges() on the DataContext, I get an exception because it attempts to insert a null into the Friend and Food columns in the FriendsFoods table. I'm sure I can put together some kind of convoluted logic to track changes to the FriendsFoods table, intercept SubmitChanges() calls, etc to try and get this to work the way I want, but is there a nice, clean way to remove a Many-To-Many relationship with LINQ-To-SQL?

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  • Extend base type and automatically update audit information on Entity

    - by Nix
    I have an entity model that has audit information on every table (50+ tables) CreateDate CreateUser UpdateDate UpdateUser Currently we are programatically updating audit information. Ex: if(changed){ entity.UpdatedOn = DateTime.Now; entity.UpdatedBy = Environment.UserName; context.SaveChanges(); } But I am looking for a more automated solution. During save changes, if an entity is created/updated I would like to automatically update these fields before sending them to the database for storage. Any suggestion on how i could do this? I would prefer to not do any reflection, so using a text template is not out of the question. A solution has been proposed to override SaveChanges and do it there, but in order to achieve this i would either have to use reflection (in which I don't want to do ) or derive a base class. Assuming i go down this route how would I achieve this? For example EXAMPLE_DB_TABLE CODE NAME --Audit Tables CREATE_DATE CREATE_USER UPDATE_DATE UPDATE_USER And if i create a base class public abstract class IUpdatable{ public virtual DateTime CreateDate {set;} public virtual string CreateUser { set;} public virtual DateTime UpdateDate { set;} public virtual string UpdateUser { set;} } The end goal is to be able to do something like... public overrride void SaveChanges(){ //Go through state manager and update audit infromation //FOREACH changed entity in state manager if(entity is IUpdatable){ //If state is created... update create audit. //if state is updated... update update audit } } But I am not sure how I go about generating the code that would extend the interface.

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  • database design to speed up hibernate querying of large dataset

    - by paddydub
    I currently have the below tables representing a bus network mapped in hibernate, accessed from a Spring MVC based bus route planner I'm trying to make my route planner application perform faster, I load all the above tables into Lists to perform the route planner logic. I would appreciate if anyone has any ideas of how to speed my performace Or any suggestions of another method to approach this problem of handling a large set of data Coordinate Connections Table (INT,INT,INT)( Containing 50,000 Coordinate Connections) ID, FROMCOORDID, TOCOORDID 1 1 2 2 1 17 3 1 63 4 1 64 5 1 65 6 1 95 Coordinate Table (INT,DECIMAL, DECIMAL) (Containing 4700 Coordinates) ID , LAT, LNG 0 59.352669 -7.264341 1 59.352669 -7.264341 2 59.350012 -7.260653 3 59.337585 -7.189798 4 59.339221 -7.193582 5 59.341408 -7.205888 Bus Stop Table (INT, INT, INT)(Containing 15000 Stops) StopID RouteID COORDINATEID 1000100001 100 17 1000100002 100 18 1000100003 100 19 1000100004 100 20 1000100005 100 21 1000100006 100 22 1000100007 100 23 This is how long it takes to load all the data from each table: stop.findAll = 148ms, stops.size: 15670 Hibernate: select coordinate0_.COORDINATEID as COORDINA1_2_, coordinate0_.LAT as LAT2_, coordinate0_.LNG as LNG2_ from COORDINATES coordinate0_ coord.findAll = 51ms , coordinates.size: 4704 Hibernate: select coordconne0_.COORDCONNECTIONID as COORDCON1_3_, coordconne0_.DISTANCE as DISTANCE3_, coordconne0_.FROMCOORDID as FROMCOOR3_3_, coordconne0_.TOCOORDID as TOCOORDID3_ from COORDCONNECTIONS coordconne0_ coordinateConnectionDao.findAll = 238ms ; coordConnectioninates.size:48132 Hibernate Annotations @Entity @Table(name = "STOPS") public class Stop implements Serializable { @Id @GeneratedValue @Column(name = "COORDINATEID") private Integer CoordinateID; @Column(name = "LAT") private double latitude; @Column(name = "LNG") private double longitude; } @Table(name = "COORDINATES") public class Coordinate { @Id @GeneratedValue @Column(name = "COORDINATEID") private Integer CoordinateID; @Column(name = "LAT") private double latitude; @Column(name = "LNG") private double longitude; } @Entity @Table(name = "COORDCONNECTIONS") public class CoordConnection { @Id @GeneratedValue @Column(name = "COORDCONNECTIONID") private Integer CoordinateID; /** * From Coordinate_id value */ @Column(name = "FROMCOORDID", nullable = false) private int fromCoordID; /** * To Coordinate_id value */ @Column(name = "TOCOORDID", nullable = false) private int toCoordID; //private Coordinate toCoordID; }

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  • Moses v1.0 multi language ini file

    - by Milan Kocic
    I was working with mosesserver 0.91 and everything works fine but now there is version 1.0 and nothing is same as before. Here is my situation: I want to have multi language translation from arabic to english and from english to arabic. All data and configuration file I have works with 0.91 version of mosesserver. Here is my config file: ------------------------------------------------- ######################### ### MOSES CONFIG FILE ### ######################### # D - decoding path, R - reordering model, L - language model [translation-systems] ar-en D 0 R 0 L 0 en-ar D 1 R 1 L 1 # input factors [input-factors] 0 # mapping steps [mapping] 0 T 0 1 T 1 # translation tables: table type (hierarchical(0), textual (0), binary (1)), source-factors, target-factors, number of scores, file # OLD FORMAT is still handled for back-compatibility # OLD FORMAT translation tables: source-factors, target-factors, number of scores, file # OLD FORMAT a binary table type (1) is assumed [ttable-file] 1 0 0 5 /mnt/models/ar-en/phrase-table/phrase-table 1 0 0 5 /mnt/models/en-ar/phrase-table/phrase-table # no generation models, no generation-file section # language models: type(srilm/irstlm), factors, order, file [lmodel-file] 1 0 5 /mnt/models/ar-en/language-model/en.qblm.mm 1 0 5 /mnt/models/en-ar/language-model/ar.lm.d1.blm.mm # limit on how many phrase translations e for each phrase f are loaded # 0 = all elements loaded [ttable-limit] 20 # distortion (reordering) files [distortion-file] 0-0 wbe-msd-bidirectional-fe-allff 6 /mnt/models/ar-en/reordering-table/reordering-table.wbe-msd-bidirectional-fe.gz 0-0 wbe-msd-bidirectional-fe-allff 6 /mnt/models/en-ar/reordering-model/reordering-table.wbe-msd-bidirectional-fe.gz # distortion (reordering) weight [weight-d] 0.3 0.3 # lexicalised distortion weights [weight-lr] 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 # language model weights [weight-l] 0.5000 0.5000 # translation model weights [weight-t] 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 # no generation models, no weight-generation section # word penalty [weight-w] -1 -1 [distortion-limit] 12 --------------------------------------------------------- So please can someone help me and rewrite this config file so it can work in version 1.0. And i need some python sample code of translation. I am using xmlrpc in python and earler I sent http request with: import xmlrpclib client = xmlrpclib.ServerProxy('http://localhost:8080') client.translate({'text': 'some text', 'system': 'en-ar'}) but now seems there is no more 'system' parameter and moses use always default settings.

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  • XPath with optional tbody element

    - by Phrogz
    As in this Stack Overflow answer imagine that you need to select a particular table and then all the rows of it. Due to the permissiveness of HTML, all three of the following are legal markup: <table id="foo"><tr>...</tr></table> <table id="foo"><tbody><tr>...</tr></tbody></table> <table id="foo"><tr>...</tr><tbody><tr>...</tr></tbody></table> You are worried about tables nested in tables, and so don't want to use an XPath like table[@id="foo"]//tr. If you could specify your desired XPath as a regex, it might look something like: table[@id="foo"](/tbody)?/tr In general, how can you specify an XPath expression that allows an optional element in the hierarchy of a selector? To be clear, I'm not trying to solve a real-world problem or select a specific element of a specific document. I'm asking for techniques to solve a class of problems.

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  • SQL Query for generating matrix like output querying related table in SQL Server

    - by Nagesh
    I have three tables: Product ProductID ProductName 1 Cycle 2 Scooter 3 Car Customer CustomerID CustomerName 101 Ronald 102 Michelle 103 Armstrong 104 Schmidt 105 Peterson Transactions TID ProductID CustomerID TranDate Amount 10001 1 101 01-Jan-11 25000.00 10002 2 101 02-Jan-11 98547.52 10003 1 102 03-Feb-11 15000.00 10004 3 102 07-Jan-11 36571.85 10005 2 105 09-Feb-11 82658.23 10006 2 104 10-Feb-11 54000.25 10007 3 103 20-Feb-11 80115.50 10008 3 104 22-Feb-11 45000.65 I have written a query to group the transactions like this: SELECT P.ProductName AS Product, C.CustName AS Customer, SUM(T.Amount) AS Amount FROM Transactions AS T INNER JOIN Product AS P ON T.ProductID = P.ProductID INNER JOIN Customer AS C ON T.CustomerID = C.CustomerID WHERE T.TranDate BETWEEN '2011-01-01' AND '2011-03-31' GROUP BY P.ProductName, C.CustName ORDER BY P.ProductName which gives the result like this: Product Customer Amount Car Armstrong 80115.50 Car Michelle 36571.85 Car Schmidt 45000.65 Cycle Michelle 15000.00 Cycle Ronald 25000.00 Scooter Peterson 82658.23 Scooter Ronald 98547.52 Scooter Schmidt 54000.25 I need result of query in MATRIX form like this: Customer |------------ Amounts --------------- Name |Car Cycle Scooter Totals Armstrong 80115.50 0.00 0.00 80115.50 Michelle 36571.85 15000.00 0.00 51571.85 Ronald 0.00 25000.00 98547.52 123547.52 Peterson 0.00 0.00 82658.23 82658.23 Schmidt 45000.65 0.00 54000.25 99000.90 Please help me to acheive the above result in SQL Server 2005. Using mulitple views or even temporory tables is fine for me.

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  • Custom Repeater with hiractial Databinding

    - by Dooie
    Im using a Custom NestedRepeater Control for ASP.NET which can be found on code project The source is in c# which i have converted to vb and plugged into my solution, so far so good. The problem, im having is databinding to the repeater, my code behind looks like this... '' get all pages Dim navPages As DataSet = Navigation.getMenuStructure() navPages.Relations.Add(navPages.Tables(0).Columns("ID"), navPages.Tables(0).Columns("ParentID")) NestedRepeaterNavigation.RelationName = RelationName NestedRepeaterNavigation.DataSource = navPages NestedRepeaterNavigation.RowFilterTop = "ParentID is null" NestedRepeaterNavigation.DataBind() Then in the item template of my custom repeater im trying the following... <ItemTemplate> <img src="/pix.gif" height="10" width="<%#(Container.Depth * 10)%>"> <%# (Container.DataItem as DataRow)["DESCRIPTION"]%> <%# (Container.NbChildren != 0 ? "<small><i>(" + Container.NbChildren.ToString() +")</i></small>" "") %><small><i></i></small> </ItemTemplate> The databinding falls over; firstly that 'as DataRow' says it was expecting an ')'. And secondly that '!=' identifier expected. Is this due to the translation from c#, should the databinding be different?

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  • sqlite3 JOIN, GROUP_CONCAT using distinct with custom separator

    - by aiwilliams
    Given a table of "events" where each event may be associated with zero or more "speakers" and zero or more "terms", those records associated with the events through join tables, I need to produce a table of all events with a column in each row which represents the list of "speaker_names" and "term_names" associated with each event. However, when I run my query, I have duplication in the speaker_names and term_names values, since the join tables produce a row per association for each of the speakers and terms of the events: 1|Soccer|Bobby|Ball 2|Baseball|Bobby - Bobby - Bobby|Ball - Bat - Helmets 3|Football|Bobby - Jane - Bobby - Jane|Ball - Ball - Helmets - Helmets The group_concat aggregate function has the ability to use 'distinct', which removes the duplication, though sadly it does not support that alongside the custom separator, which I really need. I am left with these results: 1|Soccer|Bobby|Ball 2|Baseball|Bobby|Ball,Bat,Helmets 3|Football|Bobby,Jane|Ball,Helmets My question is this: Is there a way I can form the query or change the data structures in order to get my desired results? Keep in mind this is a sqlite3 query I need, and I cannot add custom C aggregate functions, as this is for an Android deployment. I have created a gist which makes it easy for you to test a possible solution: https://gist.github.com/4072840

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  • Why use SQL database?

    - by martinthenext
    I'm not quite sure stackoverflow is a place for such a general question, but let's give it a try. Being exposed to the need of storing application data somewhere, I've always used MySQL or sqlite, just because it's always done like that. As it seems like the whole world is using these databases, most of all software products, frameworks, etc. It is rather hard for a beginning developer like me to ask a question - why? Ok, say we have some object-oriented logic in our application, and objects are related to each other somehow. We need to map this logic to the storage logic, so we need relations between database objects too. This leads us to using relational database and I'm ok with that - to put it simple, our database rows sometimes will need to have references to other tables' rows. But why do use SQL language for interaction with such a database? SQL query is a text message. I can understand this is cool for actually understanding what it does, but isn't it silly to use text table and column names for a part of application that no one ever seen after deploynment? If you had to write a data storage from scratch, you would have never used this kind of solution. Personally, I would have used some 'compiled db query' bytecode, that would be assembled once inside a client application and passed to the database. And it surely would name tables and colons by id numbers, not ascii-strings. In the case of changes in table structure those byte queries could be recompiled according to new db schema, stored in XML or something like that. What are the problems of my idea? Is there any reason for me not to write it myself and to use SQL database instead?

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  • Getting data from array of DataSet objects returned from web service

    - by Sarah Vessels
    I have a web service that I want to access when it is added as a web reference to my C# project. A particular method in the web service takes a SQL query string and returns the results of the query as a custom type. When I add the web service reference, the method shows up as returning DataSet[] instead of the custom type. This is fine provided I can still somehow access the data returned from the query within those DataSet objects. I ran a particular query that should return 6 rows; I got back a DataSet[] array with 6 elements. However, when I iterate over those DataSet objects, none of them has any tables (via the Tables property on the DataSet). What gives? Where is my data? The web service is tested and works when I use it as a data source in a Report Builder 2.0 report. I am able to send an XML SOAP query to the web service and get back XML results containing my data.

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  • Need help choosing database server

    - by The Pretender
    Good day everyone. Recently I was given a task to develop an application to automate some aspects of stocks trading. While working on initial architecture, the database dilemma emerged. What I need is a fast database engine which can process huge amounts of data coming in very fast. I'm fairly experienced in general programming, but I never faced a task of developing a high-load database architecture. I developed a simple MSSQL database schema with several many-to-many relationships during one of my projects, but that's it. What I'm looking for is some advice on choosing the most suitable database engine and some pointers to various manuals or books which describe high-load database development. Specifics of the project are as follows: OS: Windows NT family (Server 2008 / 7) Primary platform: .NET with C# Database structure: one table to hold primary items and two or three tables with foreign keys to the first table to hold additional information. Database SELECT requirements: Need super-fast selection by foreign keys and by combination of foreign key and one of the columns (presumably DATETIME) Database INSERT requirements: The faster the better :) If there'll be significant performance gain, some parts can be written in C++ with managed interfaces to the rest of the system. So once again: given all that stuff I just typed, please give me some advice on what the best database for my project is. Links or references to some manuals and books on the subject are also greatly appreciated. EDIT: I'll need to insert 3-5 rows in 2 tables approximately once in 30-50 milliseconds and I'll need to do SELECT with 0-2 WHERE clauses queries with similar rate.

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  • How do I use Linq-to-sql to iterate db records?

    - by Seth Spearman
    I asked on SO a few days ago what was the simplest quickest way to build a wrapper around a recently completed database. I took the advice and used sqlmetal to build linq classes around my database design. Now I am having two problems. One, I don't know LINQ. And, two, I have been shocked to realize how hard it is to learn. I have a book on LINQ (Linq In Action by Manning) and it has helped some but at the end of the day it is going to take me a couple of weeks to get traction and I need to make some progress on my project today. So, I am looking for some help getting started. Click HERE To see my simple database schema. Click HERE to see the vb class that was generated for the schema. My needs are simple. I have a console app. The main table is the SupplyModel table. Most of the other tables are child tables of the SupplyModel table. I want to iterate through each of Supply Model records. I want to grab the data for a supply model and then DoStuff with the data. And I also need to iterate through the child records, for each supply model, for example the NumberedInventories and DoStuff with that as well. I need help doing this in VB rather than C# if possible. I am not looking for the whole solution...if you can supply a couple of code-snippets to get me on my way that would be great. Thanks for your help. Seth

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  • Asynchronous callback - gwt

    - by sprasad12
    Hi, I am using gwt and postgres for my project. On the front end i have few widgets whose data i am trying to save on to tables at the back-end when i click on "save project" button(this also takes the name for the created project). In the asynchronous callback part i am setting more than one table. But it is not sending the data properly. I am getting the following error: org.postgresql.util.PSQLException: ERROR: insert or update on table "entitytype" violates foreign key constraint "entitytype_pname_fkey" Detail: Key (pname)=(Project Name) is not present in table "project". But when i do the select statement on project table i can see that the project name is present. Here is how the callback part looks like: oksave.addClickHandler(new ClickHandler(){ @Override public void onClick(ClickEvent event) { if(erasync == null) erasync = GWT.create(EntityRelationService.class); AsyncCallback<Void> callback = new AsyncCallback<Void>(){ @Override public void onFailure(Throwable caught) { } @Override public void onSuccess(Void result){ } }; erasync.setProjects(projectname, callback); for(int i = 0; i < boundaryPanel.getWidgetCount(); i++){ top = new Integer(boundaryPanel.getWidget(i).getAbsoluteTop()).toString(); left = new Integer(boundaryPanel.getWidget(i).getAbsoluteLeft()).toString(); if(widgetTitle.startsWith("ATTR")){ type = "regular"; erasync.setEntityAttribute(name1, name, type, top, left, projectname, callback); } else{ erasync.setEntityType(name, top, left, projectname, callback); } } } Question: Is it wrong to set more than one in the asynchronous callback where all the other tables are dependent on a particular table? when i say setProjects in the above code isn't it first completed and then moved on to the next one? Please any input will be greatly appreciated. Thank you.

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  • dynamically created radiobuttonlist

    - by Janet
    Have a master page. The content page has a list with hyperlinks containing request variables. You click on one of the links to go to the page containing the radiobuttonlist (maybe). First problem: When I get to the new page, I use one of the variables to determine whether to add a radiobuttonlist to a placeholder on the page. I tried to do it in page)_load but then couldn't get the values selected. When I played around doing it in preInit, the first time the page is there, I can't get to the page's controls. (Object reference not set to an instance of an object.) I think it has something to do with the MasterPage and page content? The controls aren't instantiated until later? (using vb by the way) Second problem: Say I get that to work, once I hit a button, can I still access the passed request variable to determine the selected item in the radiobuttonlist? Protected Sub Page_PreInit(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.PreInit 'get sessions for concurrent Dim Master As New MasterPage Master = Me.Master Dim myContent As ContentPlaceHolder = CType(Page.Master.FindControl("ContentPlaceHolder1"), ContentPlaceHolder) If Request("str") = "1" Then Dim myList As dsSql = New dsSql() ''''instantiate the function to get dataset Dim ds As New Data.DataSet ds = myList.dsConSessionTimes(Request("eid")) If ds.Tables("conSessionTimes").Rows.Count > 0 Then Dim conY As Integer = 1 CType(myContent.FindControl("lblSidCount"), Label).Text = ds.Tables("conSessionTimes").Rows.Count.ToString Sorry to be so needy - but maybe someone could direct me to a page with examples? Maybe seeing it would help it make sense? Thanks....JB

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  • Full-text search on App Engine with Whoosh

    - by Martin
    I need to do full text searching with Google App Engine. I found the project Whoosh and it works really well, as long as I use the App Engine Development Environement... When I upload my application to App Engine, I am getting the following TraceBack. For my tests, I am using the example application provided in this project. Any idea of what I am doing wrong? <type 'exceptions.ImportError'>: cannot import name loads Traceback (most recent call last): File "/base/data/home/apps/myapp/1.334374478538362709/hello.py", line 6, in <module> from whoosh import store File "/base/data/home/apps/myapp/1.334374478538362709/whoosh/__init__.py", line 17, in <module> from whoosh.index import open_dir, create_in File "/base/data/home/apps/myapp/1.334374478538362709/whoosh/index.py", line 31, in <module> from whoosh import fields, store File "/base/data/home/apps/myapp/1.334374478538362709/whoosh/store.py", line 27, in <module> from whoosh import tables File "/base/data/home/apps/myapp/1.334374478538362709/whoosh/tables.py", line 43, in <module> from marshal import loads Here is the import I have in my Python file. # Whoosh ---------------------------------------------------------------------- sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), '..', 'utils'))) from whoosh.fields import Schema, STORED, ID, KEYWORD, TEXT from whoosh.index import getdatastoreindex from whoosh.qparser import QueryParser, MultifieldParser Thank you in advance for your help!

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  • Word VBA - Find text between delimiters and convert to lower case

    - by jJack
    I would like to find text which is between the < and characters, and then turn any found text into "normal" case, where first letter of word is capitalized. Here is what I have thus far: Function findTextBetweenCarots() As String Dim strText As String With Selection .Find.Text = "<" ' what about <[^0-9]+> ? .Find.Forward = True .Find.Wrap = wdFindContinue End With Selection.Find.Execute ' Application.Selection. ' how do I get the text between the other ">"? findCarotSymb = Application.Selection.Text End Function Or, is there a better way of doing this? I also approached the problem using the VBScript Regex 5.5 library, which worked on simple documents, but not on certain documents with complex tables. For example, trying to just bold the text (for simplicity): Sub BoldUpperCaseWords() Dim regEx, Match, Matches Dim rngRange As Range Set regEx = New RegExp regEx.Pattern = "<[^0-9]+>" regEx.IgnoreCase = False regEx.Global = True Set Matches = regEx.Execute(ActiveDocument.Range.Text) For Each Match In Matches ActiveDocument.Range(Match.FirstIndex, Match.FirstIndex + Len(Match.Value)).Bold = True Next End Sub would not work in a document with tables. In fact, it would not even bold the correct text (the text between the <. This leads me to believe I have a broader issue here that I am missing. Here is what a sample doc looks like. Notice the wrong text is bold:

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  • Designing bayesian networks

    - by devoured elysium
    I have a basic question about Bayesian networks. Let's assume we have an engine, that with 1/3 probability can stop working. I'll call this variable ENGINE. If it stops working, then your car doesn't work. If the engine is working, then your car will work 99% of the time. I'll call this one CAR. Now, if your car is old(OLD), instead of not working 1/3 of the time, your engine will stop working 1/2 of the time. I'm being asked to first design the network and then assign all the conditional probabilities associated with the table. I'd say the diagram of this network would be something like OLD -> ENGINE -> CAR Now, for the conditional probabilities tables I did the following: OLD |ENGINE ------------ True | 0.50 False | 0.33 and ENGINE|CAR ------------ True | 0.99 False | 0.00 Now, I am having trouble about how to define the probabilities of OLD. In my point of view, old is not something that has a CAUSE relationship with ENGINE, I'd say it is more a characteristic of it. Maybe there is a different way to express this in the diagram? If the diagram is indeed correct, how would I go to make the tables? Thanks

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