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• Hibernate - why use many-to-one to represent a one-to-one?

  - by aberrant80

  I've seen people use many-to-one mappings to represent one-to-one relationships. I've also read this in a book by Gavin King and on articles. For example, if a customer can have exactly one shipping address, and a shipping address can belong to only one customer, the mapping is given as: <class name="Customer" table="CUSTOMERS"> ... <many-to-one name="shippingAddress" class="Address" column="SHIPPING_ADDRESS_ID" cascade="save-update" unique="true"/> ... </class> The book reasons as (quoting it): "You don't care what's on the target side of the association, so you can treat it like a to-one association without the many part." My question is, why use many-to-one and not one-to-one? What is it about a one-to-one that makes it a less desirable option to many-to-one? Thanks.

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• .Net Round-trip Types

  - by Fujiy

  I making a method that generate a unique string key for some parameters. But the same key if call with same values. I just accept primitive types, string, DateTime, Guid, and Nullable(since I append types together, I can distinguish who is int and who is int?), because I can convert all to string without lost values or precision.(for float and double a use ToString("R"), to DateTime ToString("O")). Exists a easy way to know which types I can transform in strings without conflict? And how do this transform(how I said before, float, double and datetime have specific ways) Thanks

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• using NEWSEQUENTIALID() with UPDATE Trigger

  - by Ram

  I am adding a new GUID/Uniqueidentifier column to my table. ALTER TABLE table_name ADD VersionNumber UNIQUEIDENTIFIER UNIQUE NOT NULL DEFAULT NEWSEQUENTIALID() GO And when ever a record is updated in the table, I would want to update this column "VersionNumber". So I create a new trigger CREATE TRIGGER [DBO].[TR_TABLE_NAMWE] ON [DBO].[TABLE_NAME] AFTER UPDATE AS BEGIN UPDATE TABLE_NAME SET VERSIONNUMBER=NEWSEQUENTIALID() FROM TABLE_NAME D JOIN INSERTED I ON D.ID=I.ID/* some ID which is used to join*/ END GO But just realized that NEWSEQUENTIALID() can only be used with CREATE TABLE or ALTER TABLE. I got this error The newsequentialid() built-in function can only be used in a DEFAULT expression for a column of type 'uniqueidentifier' in a CREATE TABLE or ALTER TABLE statement. It cannot be combined with other operators to form a complex scalar expression. Is there a workaround for this ? Edit1: Changing NEWSEQUENTIALID() to NEWID() in the trigger solves this, but I am indexing this column and using NEWID() would be sub-optimal

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• How can data templates in generic.xaml get applied automatically?

  - by Thiado de Arruda

  I have a custom control that has a ContentPresenter that will have an arbitrary object set as it content. This object does not have any constraint on its type, so I want this control to display its content based on any data templates defined by application or by data templates defined in Generic.xaml. If in a application I define some data template(without a key because I want it to be applied automatically to objects of that type) and I use the custom control bound to an object of that type, the data template gets applied automatically. But I have some data templates defined for some types in the generic.xaml where I define the custom control style, and these templates are not getting applied automatically. Here is the generic.xaml : If I set an object of type 'PredefinedType' as the content in the contentpresenter, the data template does not get applied. However, If it works if I define the data template in the app.xaml for the application thats using the custom control. Does someone got a clue? I really cant assume that the user of the control will define this data template, so I need some way to tie it up with the custom control.

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• Secure to store an ID in an ASP.NET control ID?

  - by Curtis White

  I'm auto-generating a form in my ASP.NET page. This is already tested and working. I want to know if: If there are any security problems with storing the database ID as part of my controls ID? I can see think of 2 issues: the id will be visible in page source (not really important in this case), and the possibility someone could change the name of the control somehow? This second possibility is more serious. Is this a potential problem and how to void it? If there would be a better preferred way to associate a unique data with any type of control? Is it possible to store a custom item in the viewstate for the control?

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• MS Excel 03 - Deleting rows that have live string identifiers in column A, while concatenating other

  - by Justin

  I have this xml document that is provided as a data feed (right off the bat I can not modify the source of the data feed) and i import it into excel with the xml import. there is no schema that comes with this xml so i get a table that ends up having a whole bunch of duplicates for an identifier, because of the unique values spread throughout the spreadsheet. XML in XLS Col1(IDnum) Col2(name) Col3(Type) Col4(Category) Col(etc) ================================================================= 0011 Item 01 6B 0011 Item xxj9 7B 0011 Item xxj9 0011 Item 02 0011 Item 01 xxj9 6B 0012 etc I need to delete all rows where columnA string/number matches while concatenating all potential values from Col3, Col4 & Col5 together so it looks like this Col1(IDnum) Col2(name) Col3(Type) Col4(Category) Col(etc) ================================================================= 0011 Item 01, 02 xxj9 6B, 7B what visual basic method would allow me to accomplish this? thanks

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• Put specific tds from a table row into edit using jQuery (then update w/ ajax)

  - by bbqsauced

  I'm somewhat new to jQuery, so I could use some help here. This is my issue: I have a php script outputting a dynamic table. Each row has an "edit" button, plus some other fields. Only 3 of those need to be turned into an input box. The edit button should only put that specific row into "edit mode." I got as far as assigning each row a unique class by adding a number to the end of it. I have been able to use jQuery to change all of the rows into edit mode, but I need it to be specific to a row. An example row would have classes like name0, price0, and desc0. The next row would go on to classes name1, price1, and desc1 (for the fields that need changed). How can I reference these values and pass them to jQuery so it processes an event on just those elements?

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• Using a JSON web service from a Java client application

  - by user383341

  I am developing a client-side Java application that has a bit of functionality that requires getting data from some web services that transmit in JSON (some RESTful, some not). No JavaScript, no web browser, just a plain JAR file that will run locally with Swing for the GUI. This is not a new or unique problem; surely there must be some open source libraries out there that will handle the JSON data transmission over HTTP. I've already found some that will parse JSON, but I'm having trouble finding any that will handle the HTTP communication to consume the JSON web service. So far I've found Apache Axis2 apparently which might have at least part of the solution, but I don't see enough documentation for it to know if it will do what I need, or how to use it. Maybe part of the problem is that I don't have experience with web services so I'm not able to know a solution when I see it. I hope some of you can point me in the right direction. Examples would be helpful.

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• Sort Java List/Map by order in which items are in an XML File

  - by Brandon Smith

  Hello everyone, What I'm looking to do is to sorta a Java List or Map in the order the items are in a XML File. For Example I have a list of function names as so: functionOne functionThree functionTwo The XML File looks like this: <xml> <function>functionOne</function> <function>functionTwo</function> <function>functionThree</function> </xml> So I would like to sort the list so the function names are as so: functionOne functionTwo functionThree Now Im trying to do this for Variables as well, so there are around 500+ unique 'items'. Does anyone have any idea how I can go about doing this? Now for the file that determines that sort order doesn't have to be XML it just what I use the most, it can be anything that can get the job done. Thanks in advance for your time.

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• importing data using get or create - identity error 1062

  - by hamackey

  I am importing data from a mssql database into mysql. Works except when it encounters the id of a previous entry. id is unique. I need to get entries that already exist so that they can be placed in the work of the day. Error is IntegrityError: (1062, "Duplicate entry '001355338' for key 2") This entry is already in the database. I need it entered for that day, but can not have it added to the table. It is already there. def handle(self, *args, **options): 59 #patients_local = Patient.objects.all() 60 #attendings_local = Attending.objects.all() 61 connection = pyodbc.connect("XXXXXXXXXXX") 62 cursor = connection.cursor() 63 cursor.execute(COMMAND) 64 rows = cursor.fetchall() 65 for row in rows: 66 # get_or_create returns (object, boolean) 67 p, created = Patient.objects.get_or_create( 68 first_name = row.Firstname, 69 middle_name = '', 70 last_name = row.Lastname, 71 id = row.id, 72 )

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• Hibernate many-to-one - bad usage?

  - by DaveA

  Just trying out Hibernate (with Annotations) and I'm having problems with my mappings. I have two entity classes, AudioCD and Artist. @Entity public class AudioCD implements CatalogItem { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; private String title; @ManyToOne(cascade = { CascadeType.ALL }, optional = false) private Artist artist; .... } @Entity @Table(uniqueConstraints = { @UniqueConstraint(columnNames = { "name" }) }) public class Artist { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; @Column(nullable = false) private String name; ..... } I get AudioCD objects from an external source. When I try to persist the AudioCD the Artist gets persisted as well, just like I want to happen. If I try persisting another different CD, but Artist already exists I get errors due to constraint violations. I want Hibernate to recognise that the Artist already exists and shouldn't be inserted again. Can this be done via annotations? Or do I have to manage the persistence of the AudioCD and Artist seperately?

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• Is this method of static file serving safe in node.js? (potential security hole?)

  - by MikeC8

  I want to create the simplest node.js server to serve static files. Here's what I came up with: fs = require('fs'); server = require('http').createServer(function(req, res) { res.end(fs.readFileSync(__dirname + '/public/' + req.url)); }); server.listen(8080); Clearly this would map http://localhost:8080/index.html to project_dir/public/index.html, and similarly so for all other files. My one concern is that someone could abuse this to access files outside of project_dir/public. Something like this, for example: http://localhost:8080/../../sensitive_file.txt I tried this a little bit, and it wasn't working. But, it seems like my browser was removing the ".." itself. Which leads me to believe that someone could abuse my poor little node.js server. I know there are npm packages that do static file serving. But I'm actually curious to write my own here. So my questions are: Is this safe? If so, why? If not, why not? And, if further, if not, what is the "right" way to do this? My one constraint is I don't want to have to have an if clause for each possible file, I want the server to serve whatever files I throw in a directory.

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• batch - append either date/time of creation or random to end of filename

  - by Maclovin

  Hi Damsel in distress needing help with a batch-script. I have a bunch of files that one system creates. Either in one of 2 directories, or in the directory above that. The naming is apparently not very important, so It's a bit random. 2 questions for you batch-geniuses out there. a) How can I append date/time of creation to the end of the filename with a batch-script? b) How can I append a random filename (so I make the files unique) with a batch-script? Thanks in advance, dudes and dudettes. Yours sincerely, the Maclovin!

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• Random select is not always returning a single row.

  - by Lieven

  The intention of following (simplified) code fragment is to return one random row. Unfortunatly, when we run this fragment in the query analyzer, it returns between zero and three results. As our input table consists of exactly 5 rows with unique ID's and as we perform a select on this table where ID equals a random number, we are stumped that there would ever be more than one row returned. Note: among other things, we already tried casting the checksum result to an integer with no avail. DECLARE @Table TABLE ( ID INTEGER IDENTITY (1, 1) , FK1 INTEGER ) INSERT INTO @Table SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 SELECT * FROM @Table WHERE ID = ABS(CHECKSUM(NEWID())) % 5 + 1

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• Can a primary key be equal to a different column?

  - by eric

  I know that a primary key must be unique, but is it okay for a primary key to be equal to a different column in the same table by coincidence? For instance, I have 2 tables. One table is called person that holds information about a person (ID, email, telephone, address, name). The other table is staff (ID, pID(person ID), salary, position). In staff the ID column is the primary key and is used to uniquely identify a staff member. The number is from 1 - 100. However, the pID (person ID) may be equal to the ID. For instance the staff ID may be 1 and the pID that it references to may be equal to 1. Is that okay?

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• How do i build a custom "Your Account" dynamic page with wordpress?

  - by Colour Blend

  Hello everyone. Please can you help with a guideline on this requirement? I have this requirement that some visitors to my site would need to login and be provided access to an Accounts page. This page will contain a list of links added by the site administrator which just lead to pages with specific contents. Every page/link is unique to a user(Account). No two user will ever have to see one page. Please help me. I just need a guide, you don't need to spoon feed me. Thanks in advance.

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• Stored Connection Strings per user

  - by pehaada

  In the past I've used a Singleton Pattern to load the connection string when the application starts via the global.asa file. I have a project now where each user has a unique connection string to the database. I would like to load this connection string once. The issue is that the singleton pattern will not work for me since each user has there own connection string. Basically the connection string is created dynamically. I do not want to store it is session. If anyway has a clever way of doing this in .NET let me know ?

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• Where does the data model go in a Prism app?

  - by HawkeyeJoeS

  I'm having trouble where to put our data model in our Prism app. Most, if not all or our data will be coming from web services and the web services are unique for each module. Unfortunately, there will be objects that need to be shared (such as a person/user object). I'm really torn about whether to add these services directly to the module, so that each is truly independent, or create a separate project to house the web service proxies and business entities. The modules are being built by different teams, but will all live in the same solution (and source control, of course).

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• How can I make this code more generic

  - by Greg

  Hi How could I make this code more generic in the sense that the Dictionary key could be a different type, depending on what the user of the library wanted to implement? For example someone might what to use the extension methods/interfaces in a case where there "unique key" so to speak for Node is actually an "int" not a "string" for example. public interface ITopology { Dictionary<string, INode> Nodes { get; set; } } public static class TopologyExtns { public static void AddNode(this ITopology topIf, INode node) { topIf.Nodes.Add(node.Name, node); } public static INode FindNode(this ITopology topIf, string searchStr) { return topIf.Nodes[searchStr]; } } public class TopologyImp : ITopology { public Dictionary<string, INode> Nodes { get; set; } public TopologyImp() { Nodes = new Dictionary<string, INode>(); } }

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• On counting pairs of words that differ by one letter

  - by Quintofron

  Let us consider n words, each of length k. Those words consist of letters over an alphabet (whose cardinality is n) with defined order. The task is to derive an O(nk) algorithm to count the number of pairs of words that differ by one position (no matter which one exactly, as long as it's only a single position). For instance, in the following set of words (n = 5, k = 4): abcd, abdd, adcb, adcd, aecd there are 5 such pairs: (abcd, abdd), (abcd, adcd), (abcd, aecd), (adcb, adcd), (adcd, aecd). So far I've managed to find an algorithm that solves a slightly easier problem: counting the number of pairs of words that differ by one GIVEN position (i-th). In order to do this I swap the letter at the ith position with the last letter within each word, perform a Radix sort (ignoring the last position in each word - formerly the ith position), linearly detect words whose letters at the first 1 to k-1 positions are the same, eventually count the number of occurrences of each letter at the last (originally ith) position within each set of duplicates and calculate the desired pairs (the last part is simple). However, the algorithm above doesn't seem to be applicable to the main problem (under the O(nk) constraint) - at least not without some modifications. Any idea how to solve this?

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• how to create a auto-incremented attribute in xcode managed object model

  - by Mausimo

  Hey, what i want to do is to make a int that will be the ID of the entity and auto increment itself whenever a new entity is added (just like a SQL identity property). Is this possible? i tried using indexed (checked on attribute) however there is no description to what indexed even does. EDIT: I am adding annotations to a map, when you click the pin the annotationview with a chevron shows up. Now when you click this button i would like to load an associated picture. However the only way i know how to link the picture to this button is to give the picture a unique id, and then set the button.tag to this id and then load based on the button.tag.

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• Deserialization of a DataSet... deal with column name changes? how to migrate data from one column to another?

  - by Brian Kennedy

  So, we wanted to slightly generalize a couple columns in our typed dataset... basically dropped a foreign key constraint and then wanted to change a couple column names to better reflect their new state. All that is easy. The problem is that our users may have serialized out the old version of the DataSet as XML. We want to be able to read those old XML files and deserialize them into the revised DataSet. It seems that would be a fairly common desire... but I haven't yet figured out the right thing to search the internet for. One possible solution would seem to be some way to give a DataColumn an alias or alternate name such that when it reads the old column name, it knows that data can be read into the column with the new column name. I can find no support for any such thing. Another approach would seem to be an "after deserialization" method of some sort... so, I would let it read in the old column values into a normal DataColumn with that name, and then in the "after deserialization" method I would just move the data from the obsolete column into the new column, and then delete the old columns. That would seem to generalize to many other situations... and having such events or hooks is pretty common in ADO.NET. But I have looked for such a hook and haven't yet found it. If no "after deserialization" hook, it would seem I ought to be able to override ReadXml or ReadXmlSerializable methods to call the base and then do my "after" stuff to fix up old data into new. But it does not appear that is possible. Soooo, I have to think backward compatibility with old serialized DataSets and simple data migration would be a well-solved problem... so, trying to reinvent that wheel seems silly. But so far, I haven't seemed to find any documentation on doing those things. Suggestions? What is best practice for this?

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• Codeigniter: how should I restructure db schema?

  - by Kevin Brown

  I don't even know if that's the right term. May it be known that I'm a major novice! I have three tables: users, profiles, and survey. Each one has user_id as it's first field, (auto-increment for users), and they're all tied by a foreign key constraint, CASCADE on DELETE. Currently, for each user, let's say user_id 1, they have a corresponding db entry in the other tables. For profiles it lists all their information, and the survey table holds all their survey information. Now I must change things...darn scope creep. Users need the ability to have multiple survey results. I imagine that this would be similar to a comment table for a blog... My entire app runs around the idea that a single user is linked to a constraining profile and survey. How should I structure my db? How should I design my app's db so that a user can have multiple tests/profiles for the test? Please assist! Any advice, information and personal-knowledge is appreciated! Right now the only way I know how to accompany my client is to create a pseudo-user for each test (so unnecessary) and list them in a view table (called "your tests")-- these are obtained from the db by saying: where user_id=manager_id

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• Batch processing JDBC

  - by Wai Hein

  I am practicing JDBC batch processing and having errors: error 1: Unsupported feature error 2: Execute cannot be empty or null Property files include: itemsdao.updateBookName = Update Books set bookname = ? where books.id = ? itemsdao.updateAuthorName = Update books set authorname = ? where books.id = ? I know I can execute about DML statements in one update, but I am practicing batch processing in JDBC. Below is my method public void update(Item item) { String query = null; try { connection = DbConnector.getConnection(); property = SqlPropertiesLoader.getProperties("dml.properties"); connection.setAutoCommit(false); if ( property == null ) { Logging.log.debug("dml.properties does not exist. Check property loader or file name is spelled right"); return; } query = property.getProperty("itemsdao.updateBookName"); statement = connection.prepareStatement(query); statement.setString(1, item.getBookName()); statement.setInt(2, item.getId()); statement.addBatch(query); query = property.getProperty("itemsdao.updateAuthorName"); statement = connection.prepareStatement(query); statement.setString(1, item.getAuthorName()); statement.setInt(2, item.getId()); statement.addBatch(query); statement.executeBatch(); connection.commit(); }catch (ClassNotFoundException e) { Logging.log.error("Connection class does not exist", e); } catch (SQLException e) { Logging.log.error("Violating PK constraint",e); } //helper class th finally { DbUtil.close(connection); DbUtil.closePreparedStatement(statement); }

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• How can one change the primary key using NHibernate.

  - by mark

  Dear ladies and sirs. I want to change the primary key of an entity in database, so that all the relevant foreign key constraints are updated as well./We are using NHibenate as our ORM. Is it possible to do it? Thanks. P.S. I know the practice of changing the primary key is highly discouraged. My problem is that my primary key is backed by a natural Id of the entity, which may sometimes change. We could, theoretically, utilize a unique primary key, unrelated to the natural key of the entity, but this complicates things too much in other places, so this is not an option.

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