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  • Howto check if a object is connected to another in hibernate

    - by codevourer
    Imagine two domain object classes, A and B. A has a bidirectional one-to-many relationship to B. A is related to thousands of B. The relations must be unique, it's not possible to have a duplicate. To check if an instance of B is already connected to a given instance of A, we could perform an easy INNER JOIN but this will only ensure the already persisted relations. What about the current transient relations? class A { @OneToMany private List<B> listOfB; } If we access the listOfB and perform a check of contains() this will fetch all the connected instances of B lazy from the datasource. I only want to validate them by their primary-key. Is there an easy solution where I can do things like "Does this instance of A is connected with this instance of B?" Without loading all these data into memory and perform a based on collections?

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  • Saving an IP adddress to DB

    - by Mark
    I want to save a user's IP address to my database just in case any legal issues come up and we need to track down who performed what action. Since I highly doubt I will ever actually need to use this data (well, maybe for counting unique hits or something) do you think I can just dump the REMOTE_ADDR into a field? If so, what should the length of that field be? 39 chars should fit an IPv6 address, no? I don't know if I'll ever get any of those, but just in case...

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  • SQL HAVING COUNT and JOIN

    - by user1833274
    I have tried to this query: What are the doctors that work on less than 2 Hospitals. I have these tables: CREATE TABLE Hospital ( hid INT PRIMARY KEY, name VARCHAR(127) UNIQUE, country VARCHAR(127), area INT ); CREATE TABLE Doctor ( ic INT PRIMARY KEY, name VARCHAR(127), date_of_birth INT, ); CREATE TABLE Work ( hid INT, ic INT, since INT, FOREIGN KEY (hid) REFERENCES Hospital (hid), FOREIGN KEY (ic) REFERENCES Doctor (ic), PRIMARY KEY (hid,ic) ); I tried with this: SELECT DISTINCT D.ic FROM Doctor D, Work W JOIN Hospital H ON (H.hid = W.hid) WHERE D.bi = W.bi GROUP BY (D.ic) HAVING COUNT(H.hid) < 2 ;

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  • ArgumentException was unhandled Application.run

    - by user369758
    Hi I've been through many sites and can't seem to find an answer. I modified a view that was connected to a Datagridview connected through a tableadapter on a C# Winforms app and in order to "reconnect" I had to delete the tableadapter and reconnect it. This was to get rid of an error regarding Unique contstraints. So I fixed that and now the application launches but when I click on the tab that that grid is on I get: System.ArgumentException was unhandled Message="Cannot bind to the property or column Id on the DataSource.\r\nParameter name: dataMember" Source="System.Windows.Forms" ParamName="dataMember" StackTrace: at System.Windows.Forms.BindToObject.CheckBinding() at System.Windows.Forms.BindToObject.SetBindingManagerBase(BindingManagerBase lManager)......... I can't seem to find an answer to this problem. Can someone help me? Thanks

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  • More than one profile in Django?

    - by JPC
    Is it possible to use Django's user authentication features with more than one profile? Currently I have a settings.py file that has this in it: AUTH_PROFILE_MODULE = 'auth.UserProfileA' and a models.py file that has this in it: from django.db import models from django.contrib.auth.models import User class UserProfileA(models.Model): company = models.CharField(max_length=30) user = models.ForeignKey(User, unique=True) that way, if a user logs in, I can easily get the profile because the User has a get_profile() method. However, I would like to add UserProfileB. From looking around a bit, it seems that the starting point is to create a superclass to use as the AUTH_PROFILE_MODULE and have both UserProfileA and UserProfileB inherit from that superclass. The problem is, I don't think the get_profile() method returns the correct profile. It would return an instance of the superclass. I come from a java background (polymorphism) so I'm not sure exactly what I should be doing. Thanks!

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  • Spring Security ACL: NotFoundException from JDBCMutableAclService.createAcl

    - by user340202
    Hello, I've been working on this task for too long to abandon the idea of using Spring Security to achieve it, but I wish that the community will provide with some support that will help reduce the regret that I have for choosing Spring Security. Enough ranting and now let's get to the point. I'm trying to create an ACL by using JDBCMutableAclService.createAcl as follows: [code] public void addPermission(IWFArtifact securedObject, Sid recipient, Permission permission, Class clazz) { ObjectIdentity oid = new ObjectIdentityImpl(clazz.getCanonicalName(), securedObject.getId()); this.addPermission(oid, recipient, permission); } @Override @Transactional(propagation = Propagation.REQUIRED, isolation = Isolation.READ_UNCOMMITTED, readOnly = false) public void addPermission(ObjectIdentity oid, Sid recipient, Permission permission) { SpringSecurityUtils.assureThreadLocalAuthSet(); MutableAcl acl; try { acl = this.mutableAclService.createAcl(oid); } catch (AlreadyExistsException e) { acl = (MutableAcl) this.mutableAclService.readAclById(oid); } // try { // acl = (MutableAcl) this.mutableAclService.readAclById(oid); // } catch (NotFoundException nfe) { // acl = this.mutableAclService.createAcl(oid); // } acl.insertAce(acl.getEntries().length, permission, recipient, true); this.mutableAclService.updateAcl(acl); } [/code] The call throws a NotFoundException from the line: [code] // Retrieve the ACL via superclass (ensures cache registration, proper retrieval etc) Acl acl = readAclById(objectIdentity); [/code] I believe this is caused by something related to Transactional, and that's why I have tested with many TransactionDefinition attributes. I have also doubted the annotation and tried with declarative transaction definition, but still with no luck. One important point is that I have used the statement used to insert the oid in the database earlier in the method directly on the database and it worked, and also threw a unique constraint exception at me when it tried to insert it in the method. I'm using Spring Security 2.0.8 and IceFaces 1.8 (which doesn't support spring 3.0 but definetely supprorts 2.0.x, specially when I keep caling SpringSecurityUtils.assureThreadLocalAuthSet()). My AppServer is Tomcat 6.0, and my DB Server is MySQL 6.0 I wish to get back a reply soon because I need to get this task off my way

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  • JQuery - which form was submitted?

    - by OneMostFrustratedChap
    Hello, I have a page of products and for each of them, I want to have a form that uses AJAX to update the session. I've done this bit - just providing background. I use the product's ID to create a different form class and name for each form, so each form is called something like this_form_name_567 and the next would be this_form_name_568 and so on. There is a submit button per form. I'm having trouble figuring out a) which event is best to use so that the correct form will be identified when a submit button is clicked, b) once clicked, how to then make sure the correct value is taken from a hidden field (unique ID) within the submitted form so that I can populate a line of code such as: $.post("compare_response.php", {compare_this: $("#compare_this").val()}, function(data){ } Any help would be greatly appreciated. Thank you

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  • Confusion in bind call in socket programming

    - by Tarun
    i was learning socket programming in unix using c/c++. I am confused with one function call bind(params..). Actually it takes the adreess structure "sockaddr_in" and we can create the structure in the following way sockaddr_in.*** = somthing.. sockaddr_in..s_addr htonl(INADDR_ANY) **Passing INADDR_ANY will alow to bind all local addresses** My question is , why do we need to use "INADDR_ANY" ? In my knowledge every machine can has only one unique IP Address. In this way there is only one address associated with the machien. Thye bind call should directly bind the socket to the single available address. Please explain what are the different scenarios and why is it so?

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  • concatenate multi values in one record without duplication

    - by mikehjun
    I have a dbf table like below which is the result of one to many join from two tables. I want to have unique zone values from one Taxlot id field. table name: input table tid ----- zone 1 ------ A 1 ------ A 1 ------ B 1 ------ C 2 ------ D 2 ------ E 3 ------ C Desirable output table table name: input table tid ----- zone 1 ------ A, B, C 2 ------ D, E 3 ------ C I got some help but couldn't make it to work. inputTbl = r"C:\temp\input.dbf" taxIdZoningDict = {} searchRows = gp.searchcursor(inputTbl) searchRow = searchRows.next() while searchRow: if searchRow.TID in taxIdZoningDict: taxIdZoningDict[searchRow.TID].add(searchRow.ZONE) else: taxIdZoningDict[searchRow.TID] = set() #a set prevents dulpicates! taxIdZoningDict[searchRow.TID].add(searchRow.ZONE) searchRow = searchRows.next() outputTbl = r"C:\temp\output.dbf" gp.CreateTable_management(r"C:\temp", "output.dbf") gp.AddField_management(outputTbl, "TID", "LONG") gp.AddField_management(outputTbl, "ZONES", "TEXT", "", "", "20") tidList = taxIdZoningDict.keys() tidList.sort() #sorts in ascending order insertRows = gp.insertcursor(outputTbl) for tid in tidList: concatString = "" for zone in taxIdZoningDict[tid] concatString = concatString + zone + "," insertRow = insertRows.newrow() insertRow.TID = tid insertRow.ZONES = concatString[:-1] insertRows.insertrow(insertRow) del insertRow del insertRows

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  • How can I generate a random human-readable colour from a seed? C#

    - by SLC
    Got a logfile, and it has all kinds of text in it. Currently it is just displayed as one colour, and each entry says something like: Log from section 1: Some text here Log from section 125: Some text here Log from section 17: Some text here Log from section 1: Some text here Log from section 125: Some text here Log from section 1: Some text here Log from section 17: Some text here Now the logfile is displayed in real time, and it would be nice to make the rows with the same section number the same colour. However there could be potentially quite a large range of numbers. What I want to do is create a method that will take a number, and randomly generate a unique colour. The colour must be readable against a black background though, so #000000 is no good, nor is #101010 or anything too dark to read. Ideally two similar numbers will not produce the same colour because in the above examples, the numbers 1 and 17 might be too similar, and some numbers might be in the 10,000 range. Any ideas on this?

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  • NHibernate many-to-many mapping

    - by Scozzard
    Hi, I am having an issue with many-to-many mapping using NHibernate. Basically I have 2 classes in my object model (Scenario and Skill) mapping to three tables in my database (Scenario, Skill and ScenarioSkill). The ScenarioSkills table just holds the IDs of the SKill and Scenario table (SkillID, ScenarioID). In the object model a Scenario has a couple of general properties and a list of associated skills (IList) that is obtained from the ScenarioSkills table. There is no associated IList of Scenarios for the Skill object. The mapping from Scenario and Skill to ScenarioSkill is a many-to-many relationship: Scenario * --- * ScenarioSkill * --- * Skill I have mapped out the lists as bags as I believe this is the best option to use from what I have read. The mappings are as follows: Within the Scenario class <bag name="Skills" table="ScenarioSkills"> <key column="ScenarioID" foreign-key="FK_ScenarioSkill_ScenarioID"/> <many-to-many class="Domain.Skill, Domain" column="SkillID" /> </bag> And within the Skill class <bag name="Scenarios" table="ScenarioSkills" inverse="true" access="noop" cascade="all"> <key column="SkillID" foreign-key="FK_ScenarioSkill_SkillID" /> <many-to-many class="Domain.Scenario, Domain" column="ScenarioID" /> </bag> Everything works fine, except when I try to delete a skill, it cannot do so as there is a reference constraint on the SkillID column of the ScenarioSkill table. Can anyone help me? I am using NHibernate 2 on an C# asp.net 3.5 web application solution.

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  • How to remove a single event in a recuring event

    - by albertos
    hi all. I' m having an issue with fullCalendar. I created a script that, adds an event to fullCalendar, along a day range, and set a unique id in order to have this event recur. let say for example that i have a recuring event from 1/1/10 till 10/1/10. i create 10 single event Objects with the same id, and place then on fullCalendar. my question is, that i want to exclude a single day over this recuring event. (for example 3/1/10). i found out, that if i remove that particural event from the sources table and then update the event its fine. but how can i get on runtime the actucal index of this eventObj on sources table? Note that, i add the events on the fullCalendar using the .fullCalendar("renderEvent") method. Thanks.

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  • Improve this generic abstract class

    - by Keivan
    I have the following abstract class design, I was wondering if anyone can suggest any improvements in terms of stronger enforcement of our requirements or simplifying implementing of the ControllerBase. //Dependency Provider base public abstract class ControllerBase<TContract, TType> where TType : TContract, class { public static TContract Instance { get { return ComponentFactory.GetComponent<TContract, TType>(); } } public TContract GetComponent<TContract, TType>() where TType : TContract, class { component = (TType)Activator.CreateInstance(typeof(TType), true); RegisterComponentInstance<TContract>(component); } } //Contract public interface IController { void DoThing(); } //Actual Class Logic public class Controller: ControllerBase<IController,Controller> { public void DoThing(); //internal constructor internal Controller(){} } //Usage public static void Main() { Controller.Instance.DoThing(); } The following facts should always be true, TType should always implement TContract (Enforced using a generic constraint) TContract must be an interface (Can't find a way to enforce it) TType shouldn't have public constructor, just an internal one, is there any way to Enforce that using ControllerBase? TType must be an concrete class (Didn't include New() as a generic constrain since the constructors should be marked as Internal)

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  • a completely decoupled OO system ?

    - by shrini1000
    To make an OO system as decoupled as possible, I'm thinking of the following approach: 1) we run an RMI/directory like service where objects can register and discover each other. They talk to this service through an interface 2) we run a messaging service to which objects can publish messages, and register subscription callbacks. Again, this happens through interfaces 3) when object A wants to invoke a method on object B, it discovers the target object's unique identity through #1 above, and publishes a message on the message service for object B 4) message services invokes B's callback to give it the message 5) B processes the request and sends the response for A on message service 6) A's callback is called and it gets the response. I feel this system is as decoupled as practically possible, but it has the following problems: 1) communication is typically asynchronous 2) hence it's non real time 3) the system as a whole is less efficient. Are there any other practical problems where this design obviously won't be applicable ? What are your thoughts on this design in general ?

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  • JPA hibernate OneToOne mapping

    - by Stupidfrog
    enviroment: hibernate 4.1.6.final spring 3.1.2.release spring jpa 1.1.0.release postgresql 9.1-901-1.jdbc4 there is 2 table public A { private Long id; private Long name; } public B { private Long id; private Long table_a_id; } the A.id and B.id is sequential, unique , but no related.(means they are separately id for their own table). how to do mapping? i have tried some method, however the result is not i wanted, because it bind wrong. for example: public A { .... @OneToOne @JoinColumn(name = "id") private B table_b } public B { ... @JsonIgnore @OneToOne(mappedBy = "table_b") private A table_a; } when i query A the result is { "id":5, "table_b":{ "id":5, "table_a_id":4 } } obviously the data join by using their id but not joining using table_a_id. what i expect is { "id":4, "table_b":{ "id":5, "table_a_id":4 } } so can somebody teach me that, how to map this 2 table by using table b table_a_id(foregin key)

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  • Maximum number of bytes that can be sent on a TCP connection

    - by iamrohitbanga
    I initially assumed that since tcp has a sequence number field of 32 bits and each byte sent on a tcp connection is labeled with a unique number, maximum number of bytes that can be sent on a tcp connection is about 2^32-1 or 2^32-2 (which?). but now I feel that since TCP is a sliding window protocol, the wraparound of sequence numbers during the connection should not have an affect on the maximum number of bytes that can be sent over a tcp connection as long as the when wraparound occurs the old packet is no longer in the network (it is sent after 2*MSL). What is the correct answer?

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  • How to access a website's url programmatically from within the page

    - by Jeff
    For work, I am working on a site that has a feature that lets users make custom instances of the site depending on who they want to show it to. So if they want to show their potential employer a little bit about themselves, they can send them a custom url, that has a uid on the end of it that tells the database what to show and what not to when the site is loaded up. Now, I need to be able to take the value that is on the end of the url, this unique uid that corresponds with their preferences in the db, accessable on run time. Meaning that when someone types in this custom url, I need to be able to show the name of the person whose portfolio is being viewed BEFORE password authentication takes place... If I could get the URL, I suppose I could parse through it to find the necessary UID...but how do I get the url? Maybe I am just missing something here, but if anyone has any thoughts or ideas, it would be appreciated!! Thanks

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  • MYSQL Inserting rows that reference main rows.

    - by Andrew M
    I'm transferring my access logs into a database. I've got two tables: urlRequests id : int(10) host : varchar(100) path: varchar(300) unique index (host, path) urlAccesses id : int(10) request : int(10) <-- reference to urlRequests row ip : int(4) query : varchar(300) time : timestamp I need to insert a row into urlAccesses for every page load, but first a row in urlRequests has to exist with the requested host and path so that urlAccesses's row can reference it. I know I can do it this way: A. check if a row exists in urlRequests B. insert a row in urlRequests if it needs it C. insert a row into urlAccesses with the urlRequests's row id referenced That's three queries for every page load if the urlRequests row doesn't exist. I'm very new to MySQL, so I'm guessing that there's a way to go about this that would be faster and use less queries.

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  • How to perform a join with CodeIgniter's Active Record class on a multicolumn key?

    - by Scott Southworth
    I've been able to make this code work using CodeIgniter's db->query as follows: $sql = 'SELECT mapping_code,zone_name,installation_name FROM installations,appearances,zones WHERE installations.installation_id = zones.installation_fk_id AND appearances.installation_fk_id = installations.installation_id AND appearances.zone_fk_id = zones.zone_id AND appearances.barcode = ? '; return $this->db->query($sql,array($barcode)); The 'appearances' table throws a 'not unique table' error if I try this using the Active Record class. I need to join appearances on both the zone and installations tables. How can I do this?

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  • When does it make sense to use a map?

    - by kiwicptn
    I am trying to round up cases when it makes sense to use a map (set of key-value entries). So far I have two categories (see below). Assuming more exist, what are they? Please limit each answer to one unique category and put up an example. Property values (like a bean) age -> 30 sex -> male loc -> calgary Presence, with O(1) performance peter -> 1 john -> 1 paul -> 1

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  • hibernate: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException

    - by user121196
    when saving an object to database using hibernate, sometimes it fails because certain fields of the object exceed the maximum varchar length defined in the database. There force I am using the following approach: 1. attempt to save 2. if getting an DataException, then I truncate the fields in the object to the max length specified in the db definition, then try to save again. However, in the second save after truncation. I'm getting the following exception: hibernate: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot add or update a child row: a foreign key constraint fails here's the relevant code, what's wrong? public static void saveLenientObject(Object obj){ try { save2(rec); } catch (org.hibernate.exception.DataException e) { // TODO Auto-generated catch block e.printStackTrace(); saveLenientObject(rec, e); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } private static void saveLenientObject(Object rec, DataException e) { Util.truncateObject(rec); System.out.println("after truncation "); save2(rec); } public static void save2(Object obj) throws Exception{ try{ beginTransaction(); getSession().save(obj); commitTransaction(); }catch(Exception e){ e.printStackTrace(); rollbackTransaction(); //closeSession(); throw e; }finally{ closeSession(); } }

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  • Generate matrix with value flags

    - by pagid
    I do have a solution for the following problem but it's quite ugly and it can most likely be done in a much shorter way. Would be great to get your help. My input looks like this: C1 C2 A B B D D C A D and my output should look like this: A B C D 1 1 0 0 0 1 0 1 0 0 1 1 1 0 0 1 My current solution is: index <- unique(unlist(input[,1:2])) output <- matrix(0,nrows=dim(input),ncols=length(index)) for(i in 1:dim(input)) { output[i, input[i,]$C1] <- 1 output[i, input[i,]$C2] <- 1 } Of course 4-5 lines is actually fine - but even as an R beginner this doesn't feel right to use a for loop. Besides that my actual data has much more than two columns, therefore this doesn't look nice in the end. How would I do that in a smarter way? Cheers

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  • SQL query to get field value distribution

    - by Bryan Lewis
    I have a table of over 1 million test score records that basically have a unique score_ID, a subject_ID and a score given by a person. The score range for most subjects is 0-3, but some have a range of 0-4. There are about 25 possible subjects. I need to produce a score distribution report which looks like: subject_ID 0 1 2 3 4 ---------- --- --- --- --- --- 1 967 576 856 234 2 576 947 847 987 324 . . So it groups the data by subject_ID, then shows how many times a specific score value was given within that subject. Any SQL pointers to generate this would be greatly appreciated.

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  • Oracle curcular join sometimes give duplicates, but sometimes does not

    - by Kaushik
    By mistake I wrote a query like this: select * from a,b,c where a.col=b.col and b.col2=c.col2 and c.col3=a.col4 So there is a circular join here. Now the thing is sometimes this query returns duplicate result, sometimes it returns unique(correct) results. I am trying to understand why it does not give duplicate results always. Also if circular joins are not allowed, how come Oracle does not throw an error. EDIT: This is the actual query. After reading ti carefully, I am not sure anymore if this is a circular join or not.It does not seem so...but why I get duplicates only sometime? select * from a,b,c,d where a.col=b.col and b.col=c.col and c.col2=d.col2 and d.col2 =a.col2

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  • Subtracting two lists in Python

    - by wich
    In Python, How can one subtract two non-unique, unordered lists? Say we have a = [0,1,2,1,0] and b = [0, 1, 1] I'd like to do something like c = a - b and have c be [2, 0] or [0, 2] order doesn't matter to me. This should throw an exception if a does not contain all elements in b. Note this is different from sets! I'm not interested in finding the difference of the sets of elements in a and b, I'm interested in the difference between the actual collections of elements in a and b. I can probably work this out with a for loop, looking up the first element of b in a and then removing the element from b and from a, etc. But this doesn't appeal to me, I'd like to do this with list comprehension in a nice and easy way. Is this possible?

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