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  • Getting a Specified Cast is not valid while importing data from Excel using Linq to SQL

    - by niceoneishere
    This is my second post. After learning from my first post how fantastic is to use Linq to SQL, I wanted to try to import data from a Excel sheet into my SQL database. First My Excel Sheet: it contains 4 columns namely ItemNo ItemSize ItemPrice UnitsSold I have a created a database table with the following fields table name ProductsSold Id int not null identity --with auto increment set to true ItemNo VarChar(10) not null ItemSize VarChar(4) not null ItemPrice Decimal(18,2) not null UnitsSold int not null Now I created a dal.dbml file based on my database and I am trying to import the data from excel sheet to db table using the code below. Everything is happening on click of a button. private const string forecast_query = "SELECT ItemNo, ItemSize, ItemPrice, UnitsSold FROM [Sheet1$]"; protected void btnUpload_Click(object sender, EventArgs e) { var importer = new LinqSqlModelImporter(); if (fileUpload.HasFile) { var uploadFile = new UploadFile(fileUpload.FileName); try { fileUpload.SaveAs(uploadFile.SavePath); if(File.Exists(uploadFile.SavePath)) { importer.SourceConnectionString = uploadFile.GetOleDbConnectionString(); importer.Import(forecast_query); gvDisplay.DataBind(); pnDisplay.Visible = true; } } catch (Exception ex) { Response.Write(ex.Source.ToString()); lblInfo.Text = ex.Message; } finally { uploadFile.DeleteFileNoException(); } } } // Now here is the code for LinqSqlModelImporter public class LinqSqlModelImporter : SqlImporter { public override void Import(string query) { // importing data using oledb command and inserting into db using LINQ to SQL using (var context = new WSDALDataContext()) { using (var myConnection = new OleDbConnection(base.SourceConnectionString)) using (var myCommand = new OleDbCommand(query, myConnection)) { myConnection.Open(); var myReader = myCommand.ExecuteReader(); while (myReader.Read()) { context.ProductsSolds.InsertOnSubmit(new ProductsSold() { ItemNo = myReader.GetString(0), ItemSize = myReader.GetString(1), ItemPrice = myReader.GetDecimal(2), UnitsSold = myReader.GetInt32(3) }); } } context.SubmitChanges(); } } } can someone please tell me where am I making the error or if I am missing something, but this is driving me nuts. When I debugged I am getting this error when casting from a number the value must be a number less than infinity I really appreciate it

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  • Need to get Multiple tables from SqlServer at a time

    - by narmadha
    Hi ,I am working with C#.net,I am using cursor concept in my storedprocedure,While executing it in Sqlserver it is showing Multiple tables,but it is not returning multiple Tables in the code,it is returning only the first table,The following is the code which i have used: DataSet ds = new DataSet("table1"); using (SqlConnection connection = new SqlConnection(connectionstring)) { using (SqlDataAdapter da = new SqlDataAdapter("getworkpersondetails_Orderidwise", connection)) { da.SelectCommand.CommandType = CommandType.StoredProcedure; SqlParameter param; param = new SqlParameter("@OrderId", SqlDbType.Int); param.Value = OrderId; da.SelectCommand.Parameters.Add(param); param = new SqlParameter("@CompanyId", SqlDbType.Int); param.Value = CompanyId; da.SelectCommand.Parameters.Add(param); connection.Open(); da.Fill(ds); connection.Close(); return ds; } }

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  • Heavy Mysql operation & Time Constraints [closed]

    - by Rahul Jha
    There is a performance issue where that I have stuck with my application which is based on PHP & MySql. The application is for Data Migration where data has to be uploaded and after various processes (Cleaning from foreign characters, duplicate check, id generation) it has to be inserted into one central table and then to 5 different tables. There, an id is generated and that id has to be updated to central table. There are different sets of records and validation rules. The problem I am facing is that when I insert say(4K) rows file (containing 20 columns) it is working fine within 15 min it gets inserted everywhere. But, when I insert the same records again then at this time it is taking one hour to insert (ideally it should get inserted by marking earlier inserted data as duplicate). After going through the log file, I noticed is that there is a Mysql select statement where I am checking the duplicates and getting ID which are duplicates. Then I am calling a function inside for loop which is basically inserting records into 5 tables and updates id to central table. This Calling function is major time of whole process. P.S. The records has to be inserted record by record.. Kindly Suggest some solution.. //This is that sample code $query=mysql_query("SELECT DISTINCT p1.ID FROM table1 p1, table2 p2, table3 a WHERE p2.datatype =0 AND (p1.datatype =1 || p1.datatype=2) AND p2.ID =0 AND p1.ID = a.ID AND p1.coulmn1 = p2.column1 AND p1.coulmn2 = p2.coulmn2 AND a.coulmn3 = p2.column3"); $num=mysql_num_rows($query); for($i=0;$i<$num;$i++) { $f=mysql_result($query,$i,"ID"); //calling function RecordInsert($f); }

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  • Refactoring - Speed increase

    - by Michael G
    How can I make this function more efficient. It's currently running at 6 - 45 seconds. I've ran dotTrace profiler on this specific method, and it's total time is anywhere between 6,000ms to 45,000ms. The majority of the time is spent on the "MoveNext" and "GetEnumerator" calls. and example of the times are 71.55% CreateTableFromReportDataColumns - 18, 533* ms - 190 calls -- 55.71% MoveNext - 14,422ms - 10,775 calls What can I do to speed this method up? it gets called a lot, and the seconds add up: private static DataTable CreateTableFromReportDataColumns(Report report) { DataTable table = new DataTable(); HashSet<String> colsToAdd = new HashSet<String> { "DataStream" }; foreach (ReportData reportData in report.ReportDatas) { IEnumerable<string> cols = reportData.ReportDataColumns.Where(c => !String.IsNullOrEmpty(c.Name)).Select(x => x.Name).Distinct(); foreach (var s in cols) { if (!String.IsNullOrEmpty(s)) colsToAdd.Add(s); } } foreach (string col in colsToAdd) { table.Columns.Add(col); } return table; }

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  • Self-Configuring Classes W/ Command Line Args: Pattern or Anti-Pattern?

    - by dsimcha
    I've got a program where a lot of classes have really complicated configuration requirements. I've adopted the pattern of decentralizing the configuration and allowing each class to take and parse the command line/configuration file arguments in its c'tor and do whatever it needs with them. (These are very coarse-grained classes that are only instantiated a few times, so there is absolutely no performance issue here.) This avoids having to do shotgun surgery to plumb new options I add through all the levels they need to be passed through. It also avoids having to specify each configuration option in multiple places (where it's parsed and where it's used). What are some advantages/disadvantages of this style of programming? It seems to reduce separation of concerns in that every class is now doing configuration stuff, and to make programs less self-documenting because what parameters a class takes becomes less explicit. OTOH, it seems to increase encapsulation in that it makes each class more self-contained because no other part of the program needs to know exactly what configuration parameters a class might need.

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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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  • problem with enable/disable button using javascript

    - by LiveEn
    Im am trying to add a check box that will enable/disable the edit button. Im retrieving a price list and displaying it inside a table. When i add the javascript into the php code it doesn't work. Below is my code <table border="1"> <tr> <td width="100">Fee % </td> <td width="100">Price</td> <td width="100">Total</td> <td width="102">&nbsp;</td> </tr> <tr> <?php $sql1="select * from pricelist"; $result1=mysql_query($sql1) or die(mysql_error()); while ($row=mysql_fetch_array($result1)) { $id=$row['id']; $price=$row['h_price']; $a=0; print "<form id='form1' name='$a+' method='post' action=''>"; print "<td><input name='fees' value ='$fees' type='text' size='4' /></td>"; print "<td><input name='price' value ='$price' type='text' size='15' /></td>"; echo "<td><input type='checkbox' onclick='this.$a+.disabled = !this.checked;'><td>"; print"<td><input type='submit' name='$a+' value='Submit' disabled='disabled' /></td>"; print "</tr>"; print "</form>"; } ?> </table> Can someone please tell me what am i doing wrong? Thanks

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  • Problem calling stored procedure with a fixed length binary parameter using Entity Framework

    - by Dave
    I have a problem calling stored procedures with a fixed length binary parameter using Entity Framework. The stored procedure ends up being called with 8000 bytes of data no matter what size byte array I use to call the function import. To give some example, this is the code I am using. byte[] cookie = new byte[32]; byte[] data = new byte[2]; entities.Insert("param1", "param2", cookie, data); The parameters are nvarchar(50), nvarchar(50), binary(32), varbinary(2000) When I run the code through SQL profiler, I get this result. exec [dbo].[Insert] @param1=N'param1',@param2=N'param2',@cookie=0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 [SNIP because of 16000 zeros] ,@data=0x0000 All parameters went through ok other than the binary(32) cookie. The varbinary(2000) seemed to work fine and the correct length was maintained. Is there a way to prevent the extra data being sent to SQL server? This seems like a big waste of network resource.

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  • Searching with MATCH(), AGAINST() and AS score with mysqli and php

    - by Drew
    Below is the code I am using to search my table. I have made the relevant columns FULLTEXT in the table. This doesn't return me anything. Can someone tell me what it is that i'm doing wrong? Thanks in advance. $sql = 'SELECT id,uname,class,school, MATCH(uname, class, school) AGAINST(?) AS score FROM images WHERE MATCH(uname, class, school) AGAINST(? IN BOOLEAN MODE) ORDER BY score DES'; $stmt = $db_connection->prepare($sql); $stmt->bind_param('ss',$keyword,$keyword); $stmt->execute(); $stmt->store_result(); $stmt->bind_result($id,$uname,$class,$school); $xml = "<data>".PHP_EOL; while($stmt->fetch()){ $xml .= " <person>".PHP_EOL; $xml .= " <id>$id</id>".PHP_EOL; $xml .= " <name>$uname</name>".PHP_EOL; $xml .= " <class>$class</class>".PHP_EOL; $xml .= " <school>$school</school>".PHP_EOL; $xml .= " </person>".PHP_EOL; } $xml .= "</data>"; echo $xml; Below is an image of the indexes of the table:

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  • Uploading files to varbinary(max) in SQL Server -- works on one server, not the other

    - by pjabbott
    I have some code that allows users to upload file attachments into a varbinary(max) column in SQL Server from their web browser. It has been working perfectly fine for almost two years, but all of a sudden it stopped working. And it stopped working on only the production database server -- it still works fine on the development server. I can only conclude that the code is fine and there is something up with the instance of SQL Server itself. But I have no idea how to isolate the problem. I insert a record into the ATTACHMENT table, only inserting non-binary data like the title and the content type, and then chunk-upload the uploaded file using the following code: // get the file stream System.IO.Stream fileStream = postedFile.InputStream; // make an upload buffer byte[] fileBuffer; fileBuffer = new byte[1024]; // make an update command SqlCommand fileUpdateCommand = new SqlCommand("update ATTACHMENT set ATTACHMENT_DATA.WRITE(@Data, NULL, NULL) where ATTACHMENT_ID = @ATTACHMENT_ID", sqlConnection, sqlTransaction); fileUpdateCommand.Parameters.Add("@Data", SqlDbType.Binary); fileUpdateCommand.Parameters.AddWithValue("@ATTACHMENT_ID", newId); while (fileStream.Read(fileBuffer, 0, fileBuffer.Length) > 0) { fileUpdateCommand.Parameters["@Data"].Value = fileBuffer; fileUpdateCommand.ExecuteNonQuery(); <------ FAILS HERE } fileUpdateCommand.Dispose(); fileStream.Close(); Where it says "FAILS HERE", it sits for a while and then I get a SQL Server timeout error on the very first iteration through the loop. If I connect to the development database instead, everything works fine (it runs through the loop many, many times and the commit is successful). Both servers are identical (SQL Server 9.0.3042) and the schemas are identical as well. When I open Activity Monitor right after the timeout to see what's going it, it says the last command is (@Data binary(1024),@ATTACHMENT_ID decimal(4,0))update ATTACHMENT set ATTACHMENT_DATA.WRITE(@Data, NULL, NULL) where ATTACHMENT_ID = @ATTACHMENT_ID which I would expect but it also says it has a status of "Suspended" and a wait type of "PAGEIOLATCH_SH". I looked this up and it seems to be a bad thing but I can't find anything specific to my stuation. Ideas?

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  • Non-normalized association with legacy tables in Rails and ActiveRecord

    - by Thomas Holmström
    I am building a Rails application accessing a legacy system. The data model contains Customers which can have one or more Subscriptions. A Subscription always belong to one and only one Customer. Though not needed, this association is represented through a join table "subscribes", which do not have an id column: Column | Type | Modifiers -----------------+---------+----------- customer_id | integer | not null subscription_id | integer | not null I have this coded as a has_and_belongs_to_many declarations in both Customer and Subscription class Customer < Activerecord::Base has_and_belongs_to_many :subscriptions, :join_table => "subscribes", :foreign_key => "customer_id", :association_foreign_key => "subscription_id" end class Subscription < Activerecord::Base has_and_belongs_to_many :customers, :join_table => "subscribes", :foreign_key => "subscription_id", :association_foreign_key => "customer_id" end The problem I have is that there can only ever be one customer for each subscription, not many, and the join table will always contain at most one row with a certain customer_id. And thus, I don't want the association "customers" on a Subscription which returns an array of (at most one) Customer, I really do want the relation "customer" which returns the Customer associated. Is there any way to force ActiveRecord to make this a 1-to-N relation even though the join table itself seems to make it an N-to-M relation? --Thomas

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  • Combinationally unique MySQL tables

    - by Jack Webb-Heller
    So, here's the problem (it's probably an easy one :P) This is my table structure: CREATE TABLE `users_awards` ( `user_id` int(11) NOT NULL, `award_id` int(11) NOT NULL, `duplicate` int(11) NOT NULL DEFAULT '0', UNIQUE KEY `award_id` (`award_id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 So it's for a user awards system. I don't want my users to be granted the same award multiple times, which is why I have a 'duplicate' field. The query I'm trying is this (with sample data of 3 and 2) : INSERT INTO users_awards (user_id, award_id) VALUES ('3','2') ON DUPLICATE KEY UPDATE duplicate=duplicate+1 So my MySQL is a little rusty, but I set user_id to be a primary key, and award_id to be a UNIQUE key. This (kind of) created the desired effect. When user 1 was given award 2, it entered. If he/she got this twice, only one row would be in the table, and duplicate would be set to 1. And again, 2, etc. When user 2 was given award 1, it entered. If he/she got this twice, duplicate updated, etc. etc. But when user 1 is given award 1 (after user 2 has already been awarded it), user 2 (with award 1)'s duplicate field increases and nothing is added to user 1. Sorry if that's a little n00bish. Really appreciate the help! Jack

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  • Index Change event for Combobox of gridtemplateColumn in Telerik

    - by Ankur
    I can write a code. In this I can take a Template Column & in this I build a RadCombobox. When it's Index changed I want to affect the below text box. Link the selected value of the Combo box is set as Text on Below TextBox. Combo Box & Text Box are different Controls of Different Template Column. I can Write Control of Combo box like this : <telerik:RadComboBox ID="cmbGID" runat="server" DataSourceID="SqlDataSource8" DataTextField="Name" DataValueField="ID" AutoPostBack="True" OnSelectedIndexChanged="cmbGID_SelectedIndexChanged"> But I don't know the parameters of this event like this : protected void cmbGID_SelectedIndexChanged() { //code... } Any one plz tell me that parameters & tell me is that possible to set txtValue.Text = cmbGID.SelectedValue.ToString()...???

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  • Generating random numbers in C

    - by moonstruckhorrors
    While searching for Tutorials on generating random numbers in C I found This Topic When I try to use the rand() function with parameters, I always get the random number generated 0. When I try to use the rand() function with parameters, I always get the value 41. And whenever I try to use arc4random() and random() functions, I get a LNK2019 error. Here's what I'm doing: #include <stdlib.h> int main() { int x; x = rand(6); printf("%d", x); } This code always generate 41. Where am I going wrong?? P.S. : I'm running Windows XP SP3 and using VS2010 Command Prompt as compiler. P.P.S. : Took me 15 minutes to learn how to format properly.

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  • Hibernate collection mapping Problem

    - by Geln Yang
    Hi, There is a table Item like, code,name 01,parent1 02,parent2 0101,child11 0102,child12 0201,child21 0202,child22 Create a java object and hbm xml to map the table.The Item.parent is a Item whose code is equal to the first two characters of its code : class Item{ String code; String name; Item parent; List<Item> children; .... setter/getter.... } <hibernate-mapping> <class name="Item" table="Item"> <id name="code" length="4" type="string"> <generator class="assigned" /> </id> <property name="name" column="name" length="50" not-null="true" /> <many-to-one name="parent" class="Item" not-found="ignore"> <formula> <![CDATA[ (select i.code,r.name from Item i where (case length(code) when 4 then i.code=SUBSTRING(code,1,2) else false end)) ]]> </formula> </many-to-one> <bag name="children"></bag> </class> </hibernate-mapping> I try to use formula to define the many-to-one relationship,but it doesn't work!Is there something wrong?Or is there other method? Thanks! ps,I use mysql database.

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  • Raw SQL sent to SQL Server from .NET on stored procedure call

    - by Jeff Meatball Yang
    Is there a way to get the raw text that is sent to SQL Server, as seen in SQL Profiler, from the ADO.NET call? using(SqlConnection conn = new SqlConnection(connString)) { SqlCommand cmd = conn.CreateCommand(); cmd.CommandType = CommandType.StoredProcedure; cmd.CommandText = "GetSomeData"; cmd.Parameters.Add("@id").Value = someId; cmd.Parameters.Add("@someOtherParam").Value = "hello"; conn.Open(); SqlDataReader dr = cmd.ExecuteReader(); // this sends up the call: exec GetSomeData @id=24, @someOtherParam='hello' // how can I capture that and write it to debug? Debug.Write("exec GetSomeData @id=24, @someOtherParam='hello'"); }

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  • How to deal with files that are relevant to version control, but that frequently change in irrelevant ways?

    - by Jens Mühlenhoff
    .dproj files are essential for Delphi projects, so they have to be under version control. These files are controlled by the IDE and also contain some information that is frequently changed, but totally irrelevant for version control. For example: I change the start parameters of the application frequently (several times a day), but don't want to accidently commit the project file if only the part dealing with the start parameters has changed. So how to deal with this situation? A clean solution would be to take the file apart, but that isn't possible with the Delphi IDE AFAIK. Can you ignore a specific part of a file? We're using Subversion at the moment, but may migrate to Git soon.

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  • Mock a void method which change the input value

    - by Kar
    Hi, How could I mock a void method with parameters and change the value parameters? My void method looks like this: public interface IFoo { void GetValue(int x, object y) // takes x and do something then access another class to get the value of y } I prepared a delegate class: private delegate void GetValueDelegate(int x, object y); private void GetValue(int x, object y) { // process x // prepare a new object obj if (y == null) y = new Object(); if (//some checks) y = obj; } I wrote something like this: Expect.Call(delegate {x.GetValue(5, null);}).Do (new GetValueDelegate(GetValue)).IgnoreArguments().Repeat.Any(); But seems like it's not working. Any clue on what could be wrong?

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  • Django IntegrityError: foreign key violation upon delete

    - by Lukasz Korzybski
    I have Order and Shipment model. Shipment has a foreign key to Order. class Order(...): ... class Shipment() order = m.ForeignKey('Order') ... Now in one of my views I want do delete order object along with all related objects. So I invoke order.delete(). I have Django 1.0.4, PostgreSQL 8.4 and I use transaction middleware, so whole request is enclosed in single transaction. The problem is that upon order.delete() I get: ... File "/usr/local/lib/python2.6/dist-packages/django/db/backends/__init__.py", line 28, in _commit return self.connection.commit() IntegrityError: update or delete on table "main_order" violates foreign key constraint "main_shipment_order_id_fkey" on table "main_shipment" DETAIL: Key (id)=(45) is still referenced from table "main_shipment". I checked in connection.queries that proper queries are executed in proper order. First shipment is deleted, after that django executes delete on order row: {'time': '0.000', 'sql': 'DELETE FROM "main_shipment" WHERE "id" IN (17)'}, {'time': '0.000', 'sql': 'DELETE FROM "main_order" WHERE "id" IN (45)'} Foreign key have ON DELETE NO ACTION (default) and is initially deferred. I don't know why I get foreign key constraint violation. I also tried to register pre_delete signal and manually delete shipment objects before delete on order is called, but it resulted in the same error. I can change ON DELETE behaviour for this key in Postgres but it would be just a hack, I wonder if anyone has a better idea what's going on here. There is also a small detail, my Order model inherits from Cart model, so it actually doesn't have id field but cart_ptr_id and after DELETE on order is executed there is also DELETE on cart, but it seems unrelated? to the shipment-order problem so I simplified it in the example.

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  • Why is Routes.rb not loading the IPs from cache?

    - by Christian Fazzini
    I am testing this in local. My ip is 127.0.0.1. The ip_permissions table, is empty. When I browse the site, everything works as expected. Now, I want to simulate browsing the site with a banned IP. So I add the IP into the ip_permissions table via: IpPermission.create!(:ip => '127.0.0.1', :note => 'foobar', :category => 'blacklist') In Rails console, I clear the cache via; Rails.cache.clear. I browse the site. I don't get sent to pages#blacklist. If I restart the server. And browse the site, then I get sent to pages#blacklist. Why do I need to restart the server every time the ip_permissions table is updated? Shouldn't it fetch it based on cache? Routes look like: class BlacklistConstraint def initialize @blacklist = IpPermission.blacklist end def matches?(request) @blacklist.map { |b| b.ip }.include? request.remote_ip end end Foobar::Application.routes.draw do match '/(*path)' => 'pages#blacklist', :constraints => BlacklistConstraint.new .... end My model looks like: class IpPermission < ActiveRecord::Base validates_presence_of :ip, :note, :category validates_uniqueness_of :ip, :scope => [:category] validates :category, :inclusion => { :in => ['whitelist', 'blacklist'] } def self.whitelist Rails.cache.fetch('whitelist', :expires_in => 1.month) { self.where(:category => 'whitelist').all } end def self.blacklist Rails.cache.fetch('blacklist', :expires_in => 1.month) { self.where(:category => 'blacklist').all } end end

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  • TicTacToe strategic reduction

    - by NickLarsen
    I decided to write a small program that solves TicTacToe in order to try out the effect of some pruning techniques on a trivial game. The full game tree using minimax to solve it only ends up with 549,946 possible games. With alpha-beta pruning, the number of states required to evaluate was reduced to 18,297. Then I applied a transposition table that brings the number down to 2,592. Now I want to see how low that number can go. The next enhancement I want to apply is a strategic reduction. The basic idea is to combine states that have equivalent strategic value. For instance, on the first move, if X plays first, there is nothing strategically different (assuming your opponent plays optimally) about choosing one corner instead of another. In the same situation, the same is true of the center of the walls of the board, and the center is also significant. By reducing to significant states only, you end up with only 3 states for evaluation on the first move instead of 9. This technique should be very useful since it prunes states near the top of the game tree. This idea came from the GameShrink method created by a group at CMU, only I am trying to avoid writing the general form, and just doing what is needed to apply the technique to TicTacToe. In order to achieve this, I modified my hash function (for the transposition table) to enumerate all strategically equivalent positions (using rotation and flipping functions), and to only return the lowest of the values for each board. Unfortunately now my program thinks X can force a win in 5 moves from an empty board when going first. After a long debugging session, it became apparent to me the program was always returning the move for the lowest strategically significant move (I store the last move in the transposition table as part of my state). Is there a better way I can go about adding this feature, or a simple method for determining the correct move applicable to the current situation with what I have already done?

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  • Multi-Column Join in Hibernate/JPA Annotations

    - by bowsie
    I have two entities which I would like to join through multiple columns. These columns are shared by an @Embeddable object that is shared by both entities. In the example below, Foo can have only one Bar but Bar can have multiple Foos (where AnEmbeddableObject is a unique key for Bar). Here is an example: @Entity @Table(name = "foo") public class Foo { @Id @Column(name = "id") @GeneratedValue(generator = "seqGen") @SequenceGenerator(name = "seqGen", sequenceName = "FOO_ID_SEQ", allocationSize = 1) private Long id; @Embedded private AnEmbeddableObject anEmbeddableObject; @ManyToOne(targetEntity = Bar.class, fetch = FetchType.LAZY) @JoinColumns( { @JoinColumn(name = "column_1", referencedColumnName = "column_1"), @JoinColumn(name = "column_2", referencedColumnName = "column_2"), @JoinColumn(name = "column_3", referencedColumnName = "column_3"), @JoinColumn(name = "column_4", referencedColumnName = "column_4") }) private Bar bar; // ... rest of class } And the Bar class: @Entity @Table(name = "bar") public class Bar { @Id @Column(name = "id") @GeneratedValue(generator = "seqGen") @SequenceGenerator(name = "seqGen", sequenceName = "BAR_ID_SEQ", allocationSize = 1) private Long id; @Embedded private AnEmbeddableObject anEmbeddableObject; // ... rest of class } Finally the AnEmbeddedObject class: @Embeddable public class AnEmbeddedObject { @Column(name = "column_1") private Long column1; @Column(name = "column_2") private Long column2; @Column(name = "column_3") private Long column3; @Column(name = "column_4") private Long column4; // ... rest of class } Obviously the schema is poorly normalised, it is a restriction that AnEmbeddedObject's fields are repeated in each table. The problem I have is that I receive this error when I try to start up Hibernate: org.hibernate.AnnotationException: referencedColumnNames(column_1, column_2, column_3, column_4) of Foo.bar referencing Bar not mapped to a single property I have tried marking the JoinColumns are not insertable and updatable, but with no luck. Is there a way to express this with Hibernate/JPA annotations? Thank you.

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  • Using complex where clause in NHibernate mapping layer

    - by JLevett
    I've used where clauses previously in the mapping layer to prevent certain records from ever getting into my application at the lowest level possible. (Mainly to prevent having to re-write lots of lines of code to filter out the unwanted records) These have been simple, one column queries, like so this.Where("Invisible = 0"); However a scenario has appeared which requires the use of an exists sql query. exists (select ep_.Id from [Warehouse].[dbo].EventPart ep_ where Id = ep_.EventId and ep_.DataType = 4 In the above case I would usually reference the parent table Event with a short name, i.e. event_.Id however as Nhibernate generates these short names dynamically it's impossible to know what it's going to be. So instead I tried using just Id, from above ep_ where Id = ep_.EventId When the code is run, because of the dynamic short names the EventPart table short name ep_ is has another short name prefixed to it, event0_.ep_ where event0_ refers to the parent table. This causes an SQL error because of the . in between event0_ and ep_ So in my EventMap I have the following this.Where("(exists (select ep_.Id from [isnapshot.Warehouse].[dbo].EventPart ep_ where Id = ep_.EventId and ep_.DataType = 4)"); but when it's generated it creates this select cast(count(*) as INT) as col_0_0_ from [isnapshot.Warehouse].[dbo].Event event0_ where (exists (select ep_.Id from [isnapshot.Warehouse].[dbo].EventPart event0_.ep_ where event0_.Id = ep_.EventId and ep_.DataType = 4) It has correctly added the event0_ to the Id Was the mapping layer where clause built to handle this and if so where am I going wrong?

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  • How can Excel 2007 / 2010 consume a REST web service?

    - by jallen
    What options exist to consume a REST web service from within Excel 2007 / 2010? I can use XML Maps to consume a basic XML list, but that doesn't let me build a dynamic URL (so I could include parameters). For example, I can add an XML Map to Excel for http://machine/service/level/5 and display the values in the workbook just fine - no problem there. The real question is, how can I dynamically change the /5 part of the URL to come from another cell in excel? That way I can have a couple of cells that have the options (what ID, what name, etc.) and whenever those values change (ideally) a new dynamic URL would be constructed and the XML map would be refreshed. Is such a thing possible? Does anyone else have a better way to take some parameters, call a web service (REST or SOAP, I'm not picky) and shove the results back into excel for further manipulation?

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  • "Cannot load ViewState" after dynamic control changed

    - by Emil D
    In my ASP.NET page I have to dynamically choose and load a custom control, depending on the selected value in a dropdownlist.However I encountered the following problem: When the parameters of the dynamically loaded control are changed, and then the selection in the dropdownlist is changed( thus forcing me to load a different dynamic control the next time the page reloads ), I end up with a "Cannot load ViewState" exception.I assume that this happens because the ViewState is trying to restore the parameters of the old control and it doesn't find it. So , is there any way to stop the viewstate from attempting to restore the state of the non-existig control?

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