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• Pandas Dataframe add rows on top of dataframe

  - by yash.trojan.25

  I am trying to add blank rows on top of the pandas Dataframe data. Basically, some blank rows and some calculation for each row which contains calculations for Average etc. for that column. Can someone please help me how I can do this? From: A B D E F G H I J 0 -8 10 532 533 533 532 534 532 532 1 -8 12 520 521 523 523 521 521 521 2 -8 14 520 523 522 523 522 521 522 3 -4 2 526 527 527 528 528 527 529 4 -4 4 516 518 517 519 518 516 518 5 -4 6 528 529 530 531 530 528 530 6 -4 8 518 521 521 521 522 519 521 7 -4 10 524 525 525 525 525 524 524 8 -4 12 522 523 524 525 525 522 523 9 -2 2 525 526 527 527 527 525 527 10 -2 4 518 519 519 521 520 519 520 11 -2 6 520 522 522 522 522 520 523 12 -2 8 551 551 552 552 552 550 552 13 -2 10 533 534 535 536 535 534 535 14 -2 12 537 539 539 539 538 537 539 15 -2 14 528 530 530 531 530 529 530 16 -1 2 518 519 519 521 520 518 520 To: A B D E F G H I J Average 525.6 527.1 527.4 528.0 527.6 526.0 527.4 Sigma 8.6 8.3 8.5 8.1 8.3 8.3 8.4 Minimum 516 518 517 519 518 516 518 Maximum 551 551 552 552 552 550 552 0 -8 10 532 533 533 532 534 532 532 1 -8 12 520 521 523 523 521 521 521 2 -8 14 520 523 522 523 522 521 522 3 -4 2 526 527 527 528 528 527 529 4 -4 4 516 518 517 519 518 516 518 5 -4 6 528 529 530 531 530 528 530 6 -4 8 518 521 521 521 522 519 521 7 -4 10 524 525 525 525 525 524 524 8 -4 12 522 523 524 525 525 522 523 9 -2 2 525 526 527 527 527 525 527 10 -2 4 518 519 519 521 520 519 520 11 -2 6 520 522 522 522 522 520 523 12 -2 8 551 551 552 552 552 550 552 13 -2 10 533 534 535 536 535 534 535 14 -2 12 537 539 539 539 538 537 539 15 -2 14 528 530 530 531 530 529 530 16 -1 2 518 519 519 521 520 518 520

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• Using jQuery to parse an RSS feed, having trouble in firefox and chrome.

  - by sjmarshy

  I used a jQuery library called jFeed to parse and display my blogs rss feed on my personal website. It worked perfectly well at first, but upon checking later it simply displays nothing, except in Internet Explorer, where it seems to work fine. After checking the javascript console using Firebug in Firefox, it shows an error in the 'XML' tab as follows: XML Parsing Error: no element found Location: moz-nullprincipal:{3f8a0c62-32b4-4f63-b69c- 9ef402b40b64} Line Number 1, Column 1: ^ Though I have no idea what to do with this information. Here is the code I used to get the rss feed and display it (it is almost exactly the same as the example provided by the jFeed website): jQuery.getFeed({ url: 'http://sammarshalldesign.co.uk/blog/wordpress/?feed=rss2', success: function(feed) { var html = ''; for(var i = 0; i < feed.items.length && i < 5; i++) { var item = feed.items[i]; html += '<h3>' + '<a href="' + item.link + '">' + item.title + '</a>' + '</h3>'; html += '<div>' + item.description + '</div>'; }//end for jQuery('#feed').append(html); }//end feed function });//end getfeed Any help would be really appreciated.

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• Why can't I set boolean columns with update?

  - by Benjamin Oakes

  I'm making a user administration page. For the system I'm creating, users need to be approved. Sometimes, there will be many users to approve, so I'd like to make that easy. I'm storing this as a boolean column called approved. I remembered the Edit Multiple Individually Railscast and thought it would be a great fit. However, I'm running into problems which I traced back to ActiveRecord::Base#update. update works fine in this example: >> User.all.map(&:username) => ["ben", "fred"] >> h = {"1"=>{'username'=>'benjamin'}, "2"=>{"username"=>'frederick'}} => {"1"=>{"username"=>"benjamin"}, "2"=>{"username"=>"frederick"}} >> User.update(h.keys, h.values) => ... >> User.all.map(&:username) => ["benjamin", "frederick"] But not this one: >> User.all.map(&:approved) => [true, nil] >> h = {"1"=>{'approved'=>'1'}, "2"=>{'approved'=>'1'}} >> User.update(h.keys, h.values) => ... >> User.all.map(&:approved) => [true, nil] Chaging from '1' to true didn't make a difference when I tested. What am I doing wrong?

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• checkbox like radiobutton wpf c#

  - by rockenpeace

  i have investigated this problem but this is solved in design view and code-behind. but my problem is little difference: i try to do this as only code-behind because my checkboxes are dynamically created according to database data.In other words, number of my checkboxes is not stable. i want to check only one checkbox in group of checkboxes. when i clicked one checkbox,i want that ischecked property of other checkboxes become false.this is same property in radiobuttons. i take my checkboxes from a stackpanel in xaml side: <StackPanel Margin="4" Orientation="Vertical" Grid.Row="1" Grid.Column="1" Name="companiesContainer"> </StackPanel> my xaml.cs: using (var c = new RSPDbContext()) { var q = (from v in c.Companies select v).ToList(); foreach (var na in q) { CheckBox ch = new CheckBox(); ch.Content = na.Name; ch.Tag = na; companiesContainer.Children.Add(ch); } } foreach (object i in companiesContainer.Children) { CheckBox chk = (CheckBox)i; chk.SetBinding(ToggleButton.IsCheckedProperty, "DataItem.IsChecked"); } how can i provide this property in checkboxes in xaml.cs ? thanks in advance..

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• C# WPF XAML Problem with icon in GridViewColumn

  - by Alex

  I've created a ListView with a GridView component in it. Now trying to fill one of the cells with an icon (PNG) like in the code sample below (save_icon.png): <ListView.View> <GridView> <GridViewColumn Header="Date" Width="Auto" DisplayMemberBinding="{Binding Date}" /> <GridViewColumn Header="Time" Width="Auto" DisplayMemberBinding="{Binding Time}" /> <GridViewColumn Header="FriendlyName" Width="Auto" DisplayMemberBinding="{Binding FriendlyName}" /> <GridViewColumn Width="Auto"> <Image Source="save_icon.png" /> </GridViewColumn> </GridView> </ListView.View> Visual Studio gives me an error on the line, where i put the icon into the column (ERROR: "Error 35: The file save_icon.png is not part of the project or its 'Build Action' property is not set to 'Resource'.") I added the icon to the project as a resource and when i start the app, everything works (the icon appears at the right place). But the WPF designer window can't be reloaded and i'm not able to see changes in the designer, when i change the XAML code. Can somebody explain this error or am i doing something wrong? Thanks for every hint in advance!

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• Image Wells, Core Data, and Sqlite files.

  - by Sway

  I've got a mac application that I've developed. I use it to create sqlite files that are bundled with my iphone app. The mac app uses Core Data and bindings and is working fine except for one "weird" issue. I use an NSImageView (or Image Well) to allow me to drag and drop jpg files. This is bound through to an optional binary attribute in my model class. For some reason when I drag and drop a 4k jpg file it onto the image well and save the sqlite file. The data saved to the binary column is over 15 times larger than it should be. Whereas if I use an application like SQLiteManager and add the image into the row in the database. The binary data is the correct (expected size). File 4k jpg Actual size: 2371. Persisted via Core Data size: 35810. Can anyone give me a suggestion as to why this might be happening? Do I need to set some setting in Interface Builder or write some custom code?

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• Should the entity framework + self tracking entities be saving me time

  - by sipwiz

  I've been using the entity framework in combination with the self tracking entity code generation templates for my latest silverlight to WCF application. It's the first time I've used the entity framework in a real project and my hope was that I would save myself a lot of time and effort by being able to automatically update the whole data access layer of my project when my database schema changed. Happily I've found that to be the case, updating my database schema by adding a new table, changing column names, adding new columns etc. etc. can be propagated to my business object classes by using the update from database option on the entity framework model. Where I'm hurting is the CRUD operations within my WCF service in response to actions on my Silverlight client. I use the same self tracking entity framework business objects in my Silverlight app but I find I'm continually having to fight against problems such as foreign key associations not being handled correctly when updating an object or the change tracker getting confused about the state of an object at the Silverlight end and the data access operation within the WCF layer throwing a wobbly. It's got to a point where I have now spent more time dealing with this quirks than I have on my previous project where I used Linq-to-SQL as the starting point for rolling my own business objects. Is it just me being hopeless or is the self tracking entities approach something that should be avoided until it's more mature?

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• Banning by IP with php/mysql

  - by incrediman

  I want to be able to ban users by IP. My idea is to keep a list of IP's as rows in an BannedIPs table (the IP column would be an index). To check users' IP's against the table, I will keep a session variable called $_SESSION['IP'] for each session. If on any request, $_SESSION['IP'] doesn't match $_SERVER['REMOTE_ADDR'], I will update $_SESSION['IP'] and check the BannedIPs table to see if the IP is banned. (A flag will also be saved as a session variable specifying whether or not the user is banned) Here are the things I'm wondering: Does that sound like a good strategy with regards to speed and security (would someone be able to get around the IP ban somehow, other than changing IP's)? What's the best way to structure a mysql query that checks to see if a row exists? That is, what's the best way to query the db to see if a row with a certain IP exists (to check if it's banned)? Should I save the IP's as integers or strings? Note that... I estimate there will be between 1,000-10,000 banned IP's stored in the database. $_SERVER['REMOTE_ADDR'] is the IP from which the current request was sent.

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• Avoiding CheckStyle magic number errors in JDBC queries.

  - by Dan

  Hello, I am working on a group project for class and we are trying out CheckStyle. I am fairly comfortable with Java but have never touched JDBC or done any database work before this. I was wondering if there is an elegant way to avoid magic number errors in preparedStatement calls, consider: preparedStatement = connect.prepareStatement("INSERT INTO shows " + "(showid, showtitle, showinfo, genre, youtube)" + "values (default, ?, ?, ?, ?);"); preparedStatement.setString(1, title); preparedStatement.setString(2, info); preparedStatement.setString(3, genre); preparedStatement.setString(4, youtube); result = preparedStatement.executeUpdate(); The setString methods get flagged as magic numbers, so far I just added the numbers 3-10 or so to the ignore list for magic numbers but I was wondering if there was a better way to go about inserting those values into the statement. I also beg you for any other advice that comes to mind seeing that code, I'd like to avoid developing any nasty habits, e.g. should I be using Statement or is PreparedStatement fine? Will that let me refer to column names instead? Is that ideal? etc... Thanks!

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• Transaction Isolation Level of Serializable not working for me

  - by Shahriar

  I have a website which is used by all branches of a store and what it does is that it records customer purchases into a table called myTransactions.myTransactions table has a column named SerialNumber.For each purchase i create a record in the transactions table and assign a serial to it.The stored procedure that does this calls a UDF function to get a new serialNumber before inserting the record.Like below : Create Procedure mytransaction_Insert as begin insert into myTransactions(column1,column2,column3,...SerialNumber) values( Value1 ,Value2,Value3,...., getTransactionNSerialNumber()) end Create function getTransactionNSerialNumber as begin RETURN isnull(SELECT TOP (1) SerialNumber FROM myTransactions READUNCOMMITTED ORDER BY SerialNumber DESC),0) + 1 end The website is being used by so many users in different stores at the same time and it is creating many duplicate serialNumbers(same SerialNumbers).So i added a Sql transaction with ReadCommitted level to the transaction and i still got duplicate transaction numbers.I changed it to SERIALIZABLE in order to lock the resources and i not only got duplicate transaction numbers(!!HOW!!) but i also got sporadic deadlocks between the same stored procedure calls.This is what i tried : (With ommissions of try catch blocks and rollbacks) Create Procedure mytransaction_Insert as begin SET TRANSACTION ISOLATION LEVEL SERIALIZABLE BEGIN TRASNACTION ins insert into myTransactions(column1,column2,column3,...SerialNumber) values( Value1 ,Value2 , Value3, ...., getTransactionNSerialNumber()) COMMIT TRANSACTION ins SET TRANSACTION ISOLATION READCOMMITTED end I even copied the function that gets the serial number directly into the stored procedure instead of the UDF function call and still got duplicate serialNumbers.So,How can a stored procedure line create something Like the c# lock() {} block. By the way,i have to implement the transaction serial number using the same pattern and i can't change the serialNumber to any other identity field or whatever.And for some reasons i need to generate the serialNumber inside the databse and i can't move SerialNumber generation to application level. Thank you.

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• Generating code -- is there an easy way to get a proper string representation of nullable type?

  - by Cory Larson

  So I'm building an application that is going to do a ton of code generation with both C# and VB output (depending on project settings). I've got a CodeTemplateEngine, with two derived classes VBTemplateEngine and CSharpTemplateEngine. This question regards creating the property signatures based on columns in a database table. Using the IDataReader's GetSchemaTable method I gather the CLR type of the column, such as "System.Int32", and whether it IsNullable. However, I'd like to keep the code simple, and instead of having a property that looks like: public System.Int32? SomeIntegerColumn { get; set; } or public Nullable<System.Int32> SomeIntegerColumn { get; set; }, where the property type would be resolved with this function (from my VBTemplateEngine), public override string ResolveCLRType(bool? isNullable, string runtimeType) { Type type = TypeUtils.ResolveType(runtimeType); if (isNullable.HasValue && isNullable.Value == true && type.IsValueType) { return "System.Nullable(Of " + type.FullName + ")"; // or, for example... return type.FullName + "?"; } else { return type.FullName; } }, I would like to generate a simpler property. I hate the idea of building a Type string from nothing, and I would rather have something like: public int? SomeIntegerColumn { get; set; } Is there anything built-in anywhere, such as in the VBCodeProvider or CSharpCodeProvider classes that would somehow take care of this for me? Or is there a way to get a type alias of int? from a type string like System.Nullable'1[System.Int32]? Thanks!

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• HOWTO - Compare a date string to datetime in SQL Server?

  - by Guy

  In SQL Server I have a DATETIME column which includes a time element. Example: '14 AUG 2008 14:23:019' What is the best method to only select the records for a particular day, ignoring the time part? Example: (Not safe, as it does not match the time part and returns no rows) DECLARE @p_date DATETIME SET @p_date = CONVERT( DATETIME, '14 AUG 2008', 106 ) SELECT * FROM table1 WHERE column_datetime = @p_date Note: Given this site is also about jotting down notes and techniques you pick up and then forget, I'm going to post my own answer to this question as DATETIME stuff in MSSQL is probably the topic I lookup most in SQLBOL. Update Clarified example to be more specific. Edit Sorry, But I've had to down-mod WRONG answers (answers that return wrong results). @Jorrit: WHERE (date>'20080813' AND date<'20080815') will return the 13th and the 14th. @wearejimbo: Close, but no cigar! badge awarded to you. You missed out records written at 14/08/2008 23:59:001 to 23:59:999 (i.e. Less than 1 second before midnight.)

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• Retrieving many huge sized EPS files and converting them to JPEG in ASP.NET application

  - by Ashish Gupta

  I have many (600) EPS files(300 KB - 1 MB) in database. In my ASP.NET application (using ASP.NET 4.0) I need to retrieve them one by one and call a web service which would convert the content to the JPEG file and update the database (JPEGContent column with the JPEG content). However, retrieving the content for 600 of them itself takes too long from the SQL management studio itself (takes 5 minutes for 10 EPS contents). So I have two issues:- 1) How to get the EPS content ( unfortunately, selecting certain number of content is not an option :-( ):- Approach 1:- foreach(var DataRow in DataTable.Rows) { // get the Id and byte[] of EPS // Call the web method to convert EPS content to JPEG which would also update the database. } or foreach(var DataRow in DataTable.Rows) { // get only the Id of EPS // Hit database to get the content of EPS // Call the web method to convert EPS content to JPEG which would also update the database. } or Any other approach? 2) Converting EPS to JPEG using a web method for 600 contents. Ofcourse, each call would be a long running operation. Would task parellel library (TPL) be a better way to achieve this? Also, is doing the entire thing in a SQL CLR function a good idea?

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• Newbie database index question

  - by RenderIn

  I have a table with multiple indexes, several of which duplicate the same columns: Index 1 columns: X, B, C, D Index 2 columns: Y, B, C, D Index 3 columns: Z, B, C, D I'm not very knowledgeable on indexing in practice, so I'm wondering if somebody can explain why X, Y and Z were paired with these same columns. B is an effective date. C is a semi-unique key ID for this table for a specific effective date B. D is a sequence that identifies the priority of this record for the identifier C. Why not just create 6 indexes, one for each X, Y, Z, B, C, D? I want to add an index to another column T, but in some contexts I'll only be querying on T alone while in others I will also be specifying the B, C and D columns... so should I create just one index like above or should I create one for T and one for (T, B, C, D)? I've not had as much luck as expected when googling for comprehensive coverage of indexing. Any resources where I can get a through explanation and lots of examples of B-tree indexing?

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• Connecting repeatable and non-repeatble backgrounds without a seam

  - by Stiggler

  I have a 700x300 background repeating seamlessly inside of the main content-div. Now I'd like to attach a div at the bottom of the content-div, containing a different background image that isn't repeatable, connecting seamlessly with the repeatable background above it. Essentially, the non-repeatable image will look like the end piece of the repeatable image. Due to the nature of the pattern, unless the full 300px height of the background image is visible in the last repeat of the content-div's backround, the background in the div below won't seamlessly connect. Basically, I need the content div's height to be a multiple of 300px under all circumstances. What's a good approach to this sort of problem? I've tried resizing the content-div on loading the page, but this only works as long as the content div doesn't contain any resizing, dynamic content, which is not my case: function adjustContentHeight() { // Setting content div's height to nearest upper multiple of column backgrounds height, // forcing it not to be cut-off when repeated. var contentBgHeight = 300; var contentHeight = $("#content").height(); var adjustedHeight = Math.ceil(contentHeight / contentBgHeight); $("#content").height(adjustedHeight * contentBgHeight); } $(document).ready(adjustContentHeight); What I'm looking for there is a way to respond to a div resizing event, but there doesn't seem to be such a thing. Also, please assume I have no access to the JS controlling the resizing of content in the content-div, though this is potentially a way of solving the problem. Another potential solution I was thinking off was to offset the background image in the bottom div by a certain amount depending on the height of the content-div. Again, the missing piece seems to be the ability to respond to a resize event.

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• ERROR! (Using Excel's named ranges from C#)

  - by mcoolbeth

  In the following, I am trying to persist a set of objects in an excel worksheet. Each time the function is called to store a value, it should allocate the next cell of the A column to store that object. However, an exception is thrown by the Interop library on the first call to get_Range(). (right after the catch block) Does anyone know what I am doing wrong? private void AddName(string name, object value) { Excel.Worksheet jresheet; try { jresheet = (Excel.Worksheet)_app.ActiveWorkbook.Sheets["jreTemplates"]; } catch { jresheet = (Excel.Worksheet)_app.ActiveWorkbook.Sheets.Add(Type.Missing, Type.Missing, Type.Missing, Type.Missing); jresheet.Visible = Microsoft.Office.Interop.Excel.XlSheetVisibility.xlSheetVeryHidden; jresheet.Name = "jreTemplates"; jresheet.Names.Add("next", "A1", true, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); } Excel.Range cell = jresheet.get_Range("next", Type.Missing); cell.Value2 = value; string address = ((Excel.Name)cell.Name).Name; _app.ActiveWorkbook.Names.Add(name, address, false, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); cell = cell.get_Offset(1, 0); jresheet.Names.Add("next", ((Excel.Name)cell.Name).Name, true, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing); }

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• LPX-00607 for ora:contains in java but not sqlplus

  - by Windle

  Hey all, I am trying to doing some sql querys out of Oracle 11g and am having issues using ora:contains. I am using spring's jdbc impl and my code generates the sql statement: select * from view_name where column_a = ? and column_b = ? and existsNode(xmltype(clob_column), 'record/name [ora:contains(text(), "name1") 0]', 'xmlns:ora="http://xmlns.oralce.com/xdb"') = 1 I have removed the actual view / column names obviously, but when I copy that into sqlplus and substitute in random values, the select executes properly. When I try to run it in my DAO code I get this stack trace: org.springframework.jdbc.UncatergorizedSQLException: PreparedStatementCallback; uncatergorizedSQLException for SQL [the big select above]; SQL state [99999]; error code [31011]; ORA-31011: XML parsing failed. ORA-19202: Error occured in XML processing LPX-00607: Invalid reference: 'contains' ;nested exception is java.sql.SQLException: ORA-31011: XML parsing failed ORA-19202: Error occured in XML processing LPX-00607: Invalid reference: 'contains' (continues on like this for awhile....) I think it is worth mentioning that I am using maven and it is possible I am missing some dependency that is required for this. Sorry the post is so long, but I wanted to err on the side of too much info. Thanks for taking the time to read this at least =) -Windle

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• Using multiple aggregate functions in an (ANSI) SQL statement

  - by morpheous

  I have aggregate functions foo(), foobar(), fredstats(), barneystats() I want to create a domain specific query language (DSQL) above my DB, to facilitate using a domain language to query the DB. The 'language' comprises of algebraic expressions (or more specifically SQL like criteria) which I use to generate (ANSI) SQL statements which are sent to the db engine. The following lines are examples of what the language statements will look like, and hopefully, it will help further clarify the concept: **Example 1** DQL statement: foobar('yellow') between 1 and 3 and fredstats('weight') > 42 Translation: fetch all rows in an underlying table where computed values for aggregate function foobar() is between 1 and 3 AND computed value for AGG FUNC fredstats() is greater than 42 **Example 2** DQL statement: fredstats('weight') < barneystats('weight') AND foo('fighter') in (9,10,11) AND foobar('green') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 3** DQL statement: foobar('green') / foobar('red') <> 42 Translation: Fetch all rows where the specified criteria matches **Example 4** DQL statement: foobar('green') - foobar('red') >= 42 Translation: Fetch all rows where the specified criteria matches Given the following information: The table upon which the queries above are being executed is called 'tbl' table 'tbl' has the following structure (id int, name varchar(32), weight float) The result set returns only the tbl.id, tbl.name and the names of the aggregate functions as columns in the result set - so for example the foobar() AGG FUNC column will be called foobar in the result set. So for example, the first DQL query will return a result set with the following columns: id, name, foobar, fredstats Given the above, my questions then are: What would be the underlying SQL required for Example1 ? What would be the underlying SQL required for Example3 ? Given an algebraic equation comprising of AGGREGATE functions, Is there a way of generalizing the algorithm needed to generate the required ANSI SQL statement(s)? I am using PostgreSQL as the db, but I would prefer to use ANSI SQL wherever possible.

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• Hibernate : Opinions in Composite PK vs Surrogate PK

  - by Albert Kam

  As i understand it, whenever i use @Id and @GeneratedValue on a Long field inside JPA/Hibernate entity, i'm actually using a surrogate key, and i think this is a very nice way to define a primary key considering my not-so-good experiences in using composite primary keys, where : there are more than 1 business-value-columns combination that become a unique PK the composite pk values get duplicated across the table details cannot change the business value inside that composite PK I know hibernate can support both types of PK, but im left wondering by my previous chats with experienced colleagues where they said that composite PK is easier to deal with when doing complex SQL queries and stored procedure processes. They went on saying that when using surrogate keys will complicate things when doing joining and there are several condition when it's impossible to do some stuffs when using surrogate keys. Although im sorry i cant explain the detail here since i was not clear enough when they explain it. Maybe i'll put more details next time. Im currently trying to do a project, and want to try out surrogate keys, since it's not getting duplicated across tables, and we can change the business-column values. And when the need for some business value combination uniqueness, i can use something like : @Table(name="MY_TABLE", uniqueConstraints={ @UniqueConstraint(columnNames={"FIRST_NAME", "LAST_NAME"}) // name + lastName combination must be unique But im still in doubt because of the previous discussion about the composite key. Could you share your experiences in this matter ? Thank you !

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• structured vs. unstructured data in db

  - by Igor

  the question is one of design. i'm gathering a big chunk of performance data with lots of key-value pairs. pretty much everything in /proc/cpuinfo, /proc/meminfo/, /proc/loadavg, plus a bunch of other stuff, from several hundred hosts. right now, i just need to display the latest chunk of data in my UI. i will probably end up doing some analysis of the data gathered to figure out performance problems down the road, but this is a new application so i'm not sure what exactly i'm looking for performance-wise just yet. i could structure the data in the db -- have a column for each key i'm gathering. the table would end up being O(100) columns wide, it would be a pain to put into the db, i would have to add new columns if i start gathering a new stat. but it would be easy to sort/analyze the data just using SQL. or i could just dump my unstructured data blob into the table. maybe three columns -- host id, timestamp, and a serialized version of my array, probably using JSON in a TEXT field. which should I do? am i going to be sorry if i go with the unstructured approach? when doing analysis, should i just convert the fields i'm interested in and create a new, more structured table? what are the trade-offs i'm missing here?

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• problem with ajax on the hosting server

  - by nelly

  when I Implemented chatting Function , I use Ajax to send messages between file to another . so , it is working well on local host . but , when I upload it in to remote server it doesn't work. can U tell me ,why ? is an Ajax need Special configuration ? there is my files that I used : Ajax .js file witch has "ajax_send" function that i used in chatbox.js file chatbox.js file wich consest of functions i used it to send data from php file to another one and it display the state (any user sign in or new sending message and so on ..) user.php file whitch responseble to write user name in the text file usersonline.txt and then display the online users in the online users column. send.php file that write on room1.text recive.php file that read room1.txt and then write the content into the chat box I beleve that the problem comes from the ajax code in Ajax.js File so please help me find out the problem and how to solve it. is ajax needs special server settings ? because it was working at the local host !

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• Parsing tab delimited file with double quotes in Perl

  - by sfactor

  I have a data set that is tab delimited with the user-agent strings in double quotes. I need to parse each of these columns and based on the answer of my other post I used the Text::CSV module. 94410634 0 GET "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; GTB6.6; .NET CLR 2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; AskTB5.5)" 1 The code is a simple one. #!/usr/bin/perl use strict; use warnings; use Text::CSV; my $csv = Text::CSV->new(sep_char => "\t"); while (<>) { if ($csv->parse($_)) { my @columns = $csv->fields(); print "@columns\n"; } else { my $err = $csv->error_input; print "Failed to parse line: $err"; } } But i get the Failed to parse line: error when I try it on this dataset. what am I doing wrong? I need to extract the 4th column containing the user-agent strings for further processing.

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• How can I generate HTML tables in Perl?

  - by anon

  I need to create a 2 tables in HTML format. Each has 5 rows: 1st Table 1st row has FRUITS in it, occupying all columns 2nd row has January(month), occupying all columns 3rd row has names of some 6 fruits (apple, orange, grapes,...)These names do not change. so this row has 6 columns 4th row has rates for each fruit ( 10,20,30..) so this has 6 columns. 5th row has corresponding message for each fruit showing as Available or not. 2nd Table If it is available the background color for the cell should be green and if not RED. 1st row has VEGETABLES in it, occupying all columns 2nd row has February(month), occupying all columns 3rd row has names of some 6 vegetables (tomato, potato..)These names do not change. so this row has 6 columns 4th row has rates for each vegetable ( 10,20,30..) so this has 6 columns. 5th row has corresponding message for each vegetable showing as Available or not.If it is available the background color for the cell should be green and if not RED. All this data is read from a file having a particular format, it is <name of fruit/vegetable price <available or not The names of fruits and vegetable do not change , it will be same for both the tables. However, it might be possible that data for a particular fruit/vegetable is not present. if it is not present the the column for that should show N/A with white background. I cannot use MIME:Lite for this. Need to use print <<ENDHTML;

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• MySQL get list of unique items in a SET

  - by The Disintegrator

  I have a products table with a column of type SET (called especialidad), with these possible values. [0] => NADA [1] => Freestyle / BMX [2] => Street / Dirt [3] => XC / Rural Bike [4] => All Mountain [5] => Freeride / Downhill / Dual / 4x [6] => Ruta / Triathlon / Pista [7] => Comfort / City / Paseo [8] => Kids [9] => Playera / Chopper / Custom [10] => MTB recreacion [11] => Spinning / Fitness Any given product can have one or many of these i/e "Freestyle / BMX,Street / Dirt" Given a subset of the rows, I need to get a list of all the present "especialidad" values. But I need a list to be exploded and unique Article1: "Freestyle / BMX,Street / Dirt" Article2: "Street / Dirt,Kids" Article2: "Kids" Article4: "Street / Dirt,All Mountain" Article5: "Street / Dirt" I need a list like this Freestyle / BMX Street / Dirt" Kids" All Mountain" I tried with group_concat(UNIQUE) but I get a list of the permutations...

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• Ordering view by highest group count question - Ruby on Rails

  - by bgadoci

  I've read the couple of questions about this on stack overflow but can't seem to find the answer. I am trying to display the tags in my blog by the ones with the highest count in the tags table. Thanks to KandadaBoggu for helping me get the tags feature of the blog I am designing working. Here is the basics and my question. Tag belongs_to :post and Post has_many :tags. The tags table is simple really, consisting of the normal scaffolded fields plus post_id and tag_name (I actually called the column 'tag_name' instead of just 'name'). in my /views/posts/index.html/erb file I correctly am displaying the tags by group and the amount of times they are being used (appearing in the tags table). I just want to know how to order them by the highest count. Here is the code, and I currently have it set to updated_at: PostsController def index @tag_counts = Tag.count(:group => :tag_name, :order => 'updated_at DESC', :limit => 10) conditions, joins = {}, nil unless(params[:tag_name] || "").empty? conditions = ["tags.tag_name = ? ", params[:tag_name]] joins = :tags end @posts=Post.all(:joins => joins, :conditions=> conditions, :order => 'created_at DESC').paginate :page => params[:page], :per_page => 5 respond_to do |format| format.html # index.html.erb format.xml { render :xml => @posts } format.json { render :json => @posts } format.atom end end

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