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  • ASP MVC C#: LINQ Foreign Key Constraint conflicts

    - by wh0emPah
    I'm having a problem with LINQ. I have 2 tables (Parent-child relation) Table1: Events (EventID, Description) Table2: Groups (GroupID, EventID(FK), Description) Now i want to create an Event an and a child. Event e = new Event(); e.Description = "test"; Datacontext.Events.InsertOnSubmit(event) Group g = new Group(); g.Description = "test2"; g.EventID = e.EventID; Datacontext.Groups.InsertOnSubmit(g); Datacontext.SubmitChanges(); When i debug, i can see that after inserting the event. the EventID has gotten a new value (auto increment). But when Datacontext.SubmitChanges(); gets called. I get the following exception "The INSERT statement conflicted with the FOREIGN KEY constraint ... I know this can be solved by creating a relation in the LINQ diagram between Events and groups. And then setting the entity itself. But i don't want to load the events everytime i ask a list of groups. All i need is some way that when inserting the group fails, the event insert won't be comitted in the database. Sorry if this is a bit unclear, My english isn't really good. Thanks in advance!

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  • Is it possible to make a non-nullable column nullable when used in a view? (sql server)

    - by Matt
    Hi, To start off I have two tables, PersonNames and PersonNameVariations. When a name is searched, it finds the closest name to one of the ones available in PersonNames and records it in the PersonNameVariations table if it's not already in there. I am using a stored proc to search the PersonNames for a passed in PersonNameVariationand return the information on both the PersonName found and the PersonNameVariation that was compared to it. Since I am using the Entity Framework, I needed return a complex type in the Import Function but for some reason it says my current framework doesn't support it. My last option was to use an Entity to return in my stored proc instead. The result that I needed back is the information on both the PersonName that was found and the PersonNameVariation that was recorded. Since I cannot return both entities, I created a view PersonSearchVariationInfo and added it into my Entity Framework in order to use it as the entity to return. The problem is that the search will not always return a Person Name match. It needs to be able to return only the PersonNameVariation data in some cases, meaning that all the fields in the PersonSearchVariationInfo pertaining to PersonName need to be nullable. How can I take my view and make some of the fields nullable? When I do it directly in the Entity Framework I get a mapping error: Error 4 Error 3031: Problem in mapping fragments starting at line 1202:Non-nullable column myproject_vw_PersonSearchVariationInfo.DateAdded in table myproject_vw_PersonSearchVariationInfo is mapped to a nullable entity property. C:\Users\Administrator\Documents\Visual Studio 2010\Projects\MyProject\MyProject.Domain\EntityFramework\MyProjectDBEntities.edmx 1203 15 MyProject.Domain Anyone have any ideas? Thanks, Matt

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  • Deleting a user > need to also delete their project, and then activities for that project? (PHP, MyS

    - by Jamie
    Hi guys, Really stuck with this... basically my system has 4 tables; users, projects, user_projects and activities. The user table has a usertype field which defines whether or not they are admin or user (by an integer)... An admin can create a project, create an acitivity for the project and assign a user (limited access user) an activity. Therefore, this setup means that an admin is never directly associated with an activity (instead a project). When my head admin user deletes an admin, I need all projects and activities (for their projects) to be deleted also. My delete script for a user is simple so far and works, but I'm having trouble on how to gain the projectID in order to know which activities to remove (associated with the projects which are about to be deleted): $userid = $_GET['userid']; $query = "DELETE FROM users WHERE userid=".$userid; $result = mysql_query($sql, $connection) or die("Error: ".mysql_error()); $query = "DELETE FROM projects WHERE userid=".$userid; $result = mysql_query($sql, $connection) or die("Error: ".mysql_error()); $query = "DELETE FROM userprojects WHERE userid=".$userid; $result = mysql_query($sql, $connection) or die("Error: ".mysql_error()); $query = "DELETE FROM activities WHERE projectid=".$projectid; $result = mysql_query($sql, $connection) or die("Error: ".mysql_error()); Now the first three queries execute fine, obviously because the userid is being retrieved successfully. However the 4th and final query I know is wrong, because there is no projectid to be gained from anywhere, however I put it there to help understand what I am trying to get!! :D Im guessing that i would need something like 'WHERE projectid=' then something to gather the removed projects from the userid which can be related to the activities for that project(s)!! Its a simple concept but I'm having trouble...please excuse any bad code as I am learning also. Thanks for any help!

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  • Linq, Left Join and Dates...

    - by BitFiddler
    So my situation is that I have a linq-to-sql model that does not allow dates to be null in one of my tables. This is intended, because the database does not allow nulls in that field. My problem, is that when I try to write a Linq query with this model, I cannot do a left join with that table anymore because the date is not a 'nullable' field and so I can't compare it to "Nothing". Example: There is a Movie table, {ID,MovieTitle}, and a Showings table, {ID,MovieID,ShowingTime,Location} Now I am trying to write a statement that will return all those movies that have no showings. In T.SQL this would look like: Select m.* From Movies m Left Join Showings s On m.ID = s.MovieID Where s.ShowingTime is Null Now in this situation I could test for Null on the 'Location' field but this is not what I have in reality (just a simplified example). All I have are non-null dates. I am trying to write in Linq: From m In dbContext.Movies _ Group Join s In Showings on m.ID Equals s.MovieID into MovieShowings = Group _ From ms In MovieShowings.DefaultIfEmpty _ Where ms.ShowingTime is Nothing _ Select ms However I am getting an error saying 'Is' operator does not accept operands of type 'Date'. Operands must be reference or nullable types. Is there any way around this? The model is correct, there should never be a null in the Showings:ShowTime table. But if you do a left join, and there are no show times for a particular movie, then ShowTime SHOULD be Nothing for that movie... Thanks everyone for your help.

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  • JVM CMS Garbage Collecting Issues

    - by jlintz
    I'm seeing the following symptoms on an application's GC log file with the Concurrent Mark-Sweep collector: 4031.248: [CMS-concurrent-preclean-start] 4031.250: [CMS-concurrent-preclean: 0.002/0.002 secs] [Times: user=0.00 sys=0.00, real=0.00 secs] 4031.250: [CMS-concurrent-abortable-preclean-start] CMS: abort preclean due to time 4036.346: [CMS-concurrent-abortable-preclean: 0.159/5.096 secs] [Times: user=0.00 sys=0.01, real=5.09 secs] 4036.346: [GC[YG occupancy: 55964 K (118016 K)]4036.347: [Rescan (parallel) , 0.0641200 secs]4036.411: [weak refs processing, 0.0001300 secs]4036.411: [class unloading, 0.0041590 secs]4036.415: [scrub symbol & string tables, 0.0053220 secs] [1 CMS-remark: 16015K(393216K)] 71979K(511232K), 0.0746640 secs] [Times: user=0.08 sys=0.00, real=0.08 secs] The preclean process keeps aborting continously. I've tried adjusting CMSMaxAbortablePrecleanTime to 15 seconds, from the default of 5, but that has not helped. The current JVM options are as follows... Djava.awt.headless=true -Xms512m -Xmx512m -Xmn128m -XX:MaxPermSize=128m -XX:+HeapDumpOnOutOfMemoryError -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:BiasedLockingStartupDelay=0 -XX:+DoEscapeAnalysis -XX:+UseBiasedLocking -XX:+EliminateLocks -XX:+CMSParallelRemarkEnabled -verbose:gc -XX:+PrintGCTimeStamps -XX:+PrintGCDetails -XX:+PrintHeapAtGC -Xloggc:gc.log -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenPrecleaningEnabled -XX:CMSInitiatingOccupancyFraction=50 -XX:ReservedCodeCacheSize=64m -Dnetworkaddress.cache.ttl=30 -Xss128k It appears the concurrent-abortable-preclean never gets a chance to run. I read through http://blogs.sun.com/jonthecollector/entry/did_you_know which had a suggestion of enabling CMSScavengeBeforeRemark, but the side effects of pausing did not seem ideal. Could anyone offer up any suggestions? Also I was wondering if anyone had a good reference for grokking the CMS GC logs, in particular this line: [1 CMS-remark: 16015K(393216K)] 71979K(511232K), 0.0746640 secs] Not clear on what memory regions those numbers are referring to.

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  • VS2008 EF and non crud SP usage.

    - by SteveO
    Using an edmx version of EF. My returned data is a join between tables that has a COMPOUND filter on the primary table. In essence this query is going to return a SEGMENT of Law codes and descriptions that a user can tie to a Sex Offender report. I have a complex SP because Linq2SQL cannot pass in a between statement, or at least that is how I understand the error. The Code itself is broken up by '-' marks. 39-13-504 "Aggravated Sexual Battery" User wants to have a query with 4 parmas 39, 13, 500, 599. Get all codes from Title 39 and Chapter 13 with parts between 500 and 599. I have the SP in place to do the work, is there are way to consume the SP within the EF? I find many blogs about SPs with CRUD operations as their use of an SP. That doesn't fit this need at all. I do not have a single table but a join to the "prior selections" table that maps the key for the code. Any pointers on how to get a READ with an SP? TIA

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  • Opening a View with a Table without a NavigationController

    - by Ken
    Hiya, I'm pretty new to developing with Cocoa Touch/XCode and I came across a problem. I'm making a sort of RSS reader for a newssite and I have 5 views of tables navigated with 5 tabs in a TabBarController. If someone selects a newsitem I want another view to open showing the complete newsitem. My problem is that it won't work. This is my code: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection(NSInteger)section{ return [[[self rssParser]rssItems]count]; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{ UITableViewCell * cell = [tableView dequeueReusableCellWithIdentifier:@"rssItemCell"]; if(nil == cell){ cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"rssItemCell"]autorelease]; } cell.textLabel.text = [[[[self rssParser]rssItems]objectAtIndex:indexPath.row]title]; cell.detailTextLabel.text = [[[[self rssParser]rssItems]objectAtIndex:indexPath.row]description]; cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator; return cell; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [[self appDelegate] setCurrentlySelectedBlogItem:[[[self rssParser]rssItems]objectAtIndex:indexPath.row]]; [self.appDelegate loadNewsDetails]; } And it calls this method in my delegate: -(void)loadNewsDetails{ [[self rootController]pushViewController:detailController animated:YES]; } Please tell me what I'm doing wrong. BTW I do not want to use a NavigationController, just the tabbar I'm using. Thanks in advance, Ken

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  • How do you use asynchronous ORMs without huge callback chains?

    - by hornairs
    I'm using the relatively immature Joose Javascript ORM plugin (project page) to persist objects in an Appcelerator Titanium (company page) mobile project. Since it's client side storage, the application has to check to see if the database is initialized before starting up the ORM since it inspects the DB tables to construct the classes. My problem is that this sequence of operations (and if this one is like this, other things down the road) takes a lot of callbacks to complete. I have a lot of jumping around in the code that isn't apparent to a maintainer and results in some complex call graphs and whatnot. So, I ask these questions: How would you asynchronously initialize a database and populate it with seed data using an ORM that needs the schema to be correct to function? Do you have any general strategies or links for async/event driven programming and keeping the call graph simple and understandable? Do you have any suggestions for Javascript ORMs/meta object systems that work with HTML 5 as a storage engine and are hopefully framework agnostic? Am I just a big newb and should be able to work this out with ease? Thanks folks!

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  • Linq - how does it work??

    - by clarkeyboy
    Hey, I have just been looking into Linq with ASP.Net. It is very neat indeed. I was just wondering - how do all the classes get populated? I mean in ASP.Net, suppose you have a Linq file called Catalogue, and you then use a For loop to loop through Catalogue.Products and print each Product name. How do the details get stored? Does it just go through the Products table on page load and create another instance of class Product for each row, effectively copying an entire table into an array of class Product? If so, I think I have created a system very much like this, in the sense that there is a SiteContent module with an instance of each Manager class - for example there is UserManager, ProductManager, SettingManager and alike. UserManager contains an instance of the User class for each row in the Users table. They also contain methods such as Create, Update and Remove. These Managers and their "Items" are created on every page load. This just makes it nice and easy to access users, products, settings etc in every page as far as I, the developer, am concerned. Any any subsequent pages I need to create, I just need to reference SiteContent.UserManager to access a list of users, rather than executing a query from within that page (ie this method separates out data access from the workings of the page, in the same way as using code behind separates out the workings of the page from how the page is layed out). However the problem is that this technique seems rather slow. I mean it is effectively creating a database on every page load, taking data from another database. I have taken measures such as preventing, for example, the ProductManager from being created if it is not referenced on page load. Therefore it does not load data into storage when it is not needed. My question is basically whether my technique does the exact same thing as Linq, in the sense of duplicating data from tables into properties of classes.. Thanks in advance for any advice or answers about this. Regards, Richard Clarke

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  • Cannot update a single field using Linq to Sql

    - by KallDrexx
    I am having a hard time attempting to update a single field without having to retrieve the whole record prior to saving. For example, in my web application I have an in place editor for the Name and Description fields of an object. Once you edit either field, it sends the new field (with the object's ID value) to the web server. What I want is the webserver to take that value and ID and only update the one field. There are only two ways google tells me to do this: 1) When I get the value I want to change, the value and the ID, retrieve the record from the database, update the field in the c# object, and then send it back to the server. I don't like this method because not only does it include a completely unnecessary database read call (which includes two tables due to the way my schema is). 2) Set UpdateCheck for all the fields (but the primary keys) to UpdateCheck.Never. This doesn't work for me (I think) due to my mapping layer between the Linq to Sql and my Entity/ViewModel layer. When I convert my entity into the linq to sql db object it seems to be updating those fields regardless of the UpdateCheck setting. This might be just because of integers, since not setting an int means it is a zero (and no, I can't use int? instead). Are there any other options that I have?

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  • Cannot turn off autocommit in a script using the Django ORM

    - by Wes
    I have a command line script that uses the Django ORM and MySQL backend. I want to turn off autocommit and commit manually. For the life of me, I cannot get this to work. Here is a pared down version of the script. A row is inserted into testtable every time I run this and I get this warning from MySQL: "Some non-transactional changed tables couldn't be rolled back". #!/usr/bin/python import os import sys django_dir = os.path.abspath(os.path.normpath(os.path.join(os.path.dirname(__file__), '..'))) sys.path.append(django_dir) os.environ['DJANGO_DIR'] = django_dir os.environ['DJANGO_SETTINGS_MODULE'] = 'myproject.settings' from django.core.management import setup_environ from myproject import settings setup_environ(settings) from django.db import transaction, connection cursor = connection.cursor() cursor.execute('SET autocommit = 0') cursor.execute('insert into testtable values (\'X\')') cursor.execute('rollback') I also tried placing the insert in a function and adding Django's commit_manually wrapper, like so: @transaction.commit_manually def myfunction(): cursor = connection.cursor() cursor.execute('SET autocommit = 0') cursor.execute('insert into westest values (\'X\')') cursor.execute('rollback') myfunction() I also tried setting DISABLE_TRANSACTION_MANAGEMENT = True in settings.py, with no further luck. I feel like I am missing something obvious. Any help you can give me is greatly appreciated. Thanks!

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  • LINQ to DataSet Dataclass assignment question

    - by Overhed
    Hi all, I'm working on a Silverlight project trying to access a database using LINQ To DataSet and then sending data over to Silverlight via .ASMX web service. I've defined my DataSet using the Server Explorer tool (dragging and dropping all the different tables that I'm interested in). The DataSet is able to access the server and database with no issues. Below is code from one of my Web Methods: public List<ClassSpecification> getSpecifications() { DataSet2TableAdapters.SpecificationTableAdapter Sta = new DataSet2TableAdapters.SpecificationTableAdapter(); return (from Spec in Sta.GetData().AsEnumerable() select new ClassSpecification() { Specification = Spec.Field<String>("Specification"), SpecificationType = Spec.Field<string>("SpecificationType"), StatusChange = Spec.Field<DateTime>("StatusChange"), Spec = Spec.Field<int>("Spec") }).ToList<ClassSpecification>(); } I created a "ClassSpecification" data class which is going to contain my data and it has all the table fields as properties. My question is, is there a quicker way of doing the assignment than what is shown here? There are actually about 10 more fields, and I would imagine that since my DataSet knows my table definition, that I would have a quicker way of doing the assignment than going field by field. I tried just "select new ClassSpecification()).ToList Any help would be greatly appreciated.

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  • Bulk Copy from one server to another

    - by Joseph
    Hi All, I've one situation where I need to copy part of the data from one server to another. The table schema are exactly same. I need to move partial data from the source, which may or may not be available in the destination table. The solution I'm thinking is, use bcp to export data to a text(or .dat) file and then take that file to the destination as both are not accessible at the same time (Different network), then import the data to the destination. There are some conditions I need to satisfy. 1. I need to export only a list of data from the table, not whole. My client is going to give me IDs which needs to be moved from source to destination. I've around 3000 records in the master table, and same in the child tables too. What I expect is, only 300 records to be moved. 2. If the record exists in the destination, the client is going to instruct as whether to ignore or overwrite case to case. 90% of the time, we need to ignore the records without overwriting, but log the records in a log file. Please help me with the best approach. I thought of using BCP with query option to filter the data, but while importing, how do I bypass inserting the existing records? If I need to overwrite, how to do it? Thanks a lot in advance. ~Joseph

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  • MySQL use certain columns, based on other columns

    - by Rabbott
    I have this query: SELECT COUNT(articles.id) AS count FROM articles, xml_documents, streams WHERE articles.xml_document_id = xml_documents.id AND xml_documents.stream_id = streams.id AND articles.published_at BETWEEN '2010-01-01' AND '2010-04-01' AND streams.brand_id = 7 Which just uses the default equajoin by specifying three tables in csv format in the FROM clause.. What I need to do is group this by a value found within articles.source (raw xml).. so it could turn into this: SELECT COUNT(articles.id) AS count, ExtractValue(articles.source, "/article/media_type") AS media_type FROM articles, xml_documents, streams WHERE articles.xml_document_id = xml_documents.id AND xml_documents.stream_id = streams.id AND articles.published_at BETWEEN '2010-01-01' AND '2010-04-01' AND streams.brand_id = 7 GROUP BY media_type which works fine, the problem is, I'm using rails, and using STI for the xml_documents table. The articles.source that is provided to the ExtractValue method will be of a couple different formats.. So what I need to be able to do is use "/article/media_type" IF xml_documents.type = 'source one' and use "/article/source" if xml_documents.type = 'source two' This is just because the two document types format their XML differently, but I don't want to have to run multiple queries to retrieve this information.. It would be nice if one could use a ternary operator, but i don't think this is possible.. EDIT At this Point I am looking at making a temp table, or simply using UNION to place multiple result sets together..

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  • SQLCMD.EXE generates ugly report. How to format it?

    - by Juri Bogdanov
    I did batch to run SQL query like use [AxDWH_Central_Reporting] GO EXEC sp_spaceused @updateusage = N'TRUE' GO It displays 2 tables and generates some ugly report with some kind of 'P' unneeded letters... See below Changed database context to 'AxDWH_Central_Reporting'. database_name Pdatabase_size Punallocated space --------------------------------------------------------------------------------------------------------------------------------P------------------P------------------ AxDWH_Central_Reporting P10485.69 MB P7436.85 MB reserved Pdata Pindex_size Punused ------------------P------------------P------------------P------------------ 3121176 KB P3111728 KB P7744 KB P1704 KB ---------------------------------------------------------------- I also tryed to generate 1 table from this procedure with next query declare @dbname sysname, @dbsize bigint, @logsize bigint, @reservedpages bigint select @reservedpages = sum(a.total_pages) from sys.partitions p join sys.allocation_units a on p.partition_id = a.container_id left join sys.internal_tables it on p.object_id = it.object_id select @dbsize = sum(convert(bigint,case when status & 64 = 0 then size else 0 end)), @logsize = sum(convert(bigint,case when status & 64 <> 0 then size else 0 end)) from dbo.sysfiles select 'database name' = db_name(), 'database size' = ltrim(str((convert (dec (15,2),@dbsize) + convert (dec (15,2),@logsize)) * 8192 / 1048576,15,2) + ' MB'), 'unallocated space' = ltrim(str((case when @dbsize >= @reservedpages then (convert (dec (15,2),@dbsize) - convert (dec (15,2),@reservedpages)) * 8192 / 1048576 else 0 end),15,2) + ' MB') But got similar ugly report: database name Pdatabase size Punallocated space --------------------------------------------------------------------------------------------------------------------------------P------------------P------------------ master P5.75 MB P1.52 MB (1 rows affected) Is it possible to change the layout formatting for report? To make it more beautifull?

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  • Asynchronuos callback saves value but prints FAILED

    - by sprasad12
    Hi, I am using nested Asynchronous callbacks to save my front-end data to the back-end database. The data is being save into the tables the way i want them to, but it is printing that it failed. Here is the code: oksave.addClickHandler(new ClickHandler(){ public void onClick(ClickEvent event) { if(erasync == null) erasync = GWT.create(EntityRelationService.class); AsyncCallback<Void> callback = new AsyncCallback<Void>(){ public void onFailure(Throwable caught) { String msg = caught.getLocalizedMessage(); if (caught instanceof NotFoundException) { msg = ((NotFoundException) caught).getType() + ((NotFoundException) caught).getMessage(); } System.out.println("Failed" + msg); } public void onSuccess(Void result) { Label success = new Label("Name : " + pname.getText() + " was successfully saved"); Button close = new Button("close"); VerticalPanel sp = new VerticalPanel(); d1 = new DialogBox(); sp.add(success); sp.add(close); close.addClickHandler(new ClickHandler(){ @Override public void onClick(ClickEvent event) { if(erasync == null) erasync = GWT.create(EntityRelationService.class); AsyncCallback<Void> callbackOthers = new AsyncCallback<Void>(){ @Override public void onFailure(Throwable caught) { String msg = caught.getLocalizedMessage(); if (caught instanceof NotFoundException) { msg = ((NotFoundException) caught).getType() + ((NotFoundException) caught).getMessage(); } System.out.println("Failed" + msg); } @Override public void onSuccess(Void result) { System.out.println("Success"); } }; erasync.setEntityType(name, top, left, pname, callbackOthers); }); }; erasync.setProject(name, callback); }); Here it prints successful for the first callback, but for the nested one it says failed though it saves the value. Am i missing something? Any input will be of great help. Thank you.

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  • mnesia primary key

    - by maryjanne
    Hi I have two tables one notes and one tag and I want to make the id from notes primary key to use it in the tag table, but I don't know where I do wrong. My notes id is generate from another table counter, with the function dirty_update_counter. My function for the id_notes from tag looks like this: Fun = fun() -> mnesia:write(#tag{ id_note =0}) end, mnesia:transaction(Fun). generate_Oid(TableName) when is_atom(TableName) -> F = fun() -> [Oid] = mnesia:read(tag, TableName, write), NewId = Oid#tag.id_note+1, New = Oid#tag{id_note = NewId}, mnesia:write(New), NewId end, mnesia:transaction(F). insert_n(N) when is_record(N, note) -> F = fun() -> {atomic, Id} = generate_Oid(note), New = N#note{id = Id}, mnesia:write(New), New end, mnesia:transaction(F). find_n(Id) when is_integer(Id) -> {atomic, [N]} = mnesia:transaction(fun() -> mnesia:read({note, Id}) end), N. But this function don't increment my field id_note from the table tag, despite the fact that in my note table, my id field is incremented from counter table. Thanks in advance for any help.

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  • Starter question of declarative style SQLAlchemy relation()

    - by jfding
    I am quite new to SQLAlchemy, or even database programming, maybe my question is too simple. Now I have two class/table: class User(Base): __tablename__ = 'users' id = Column(Integer, primary_key=True) name = Column(String(40)) ... class Computer(Base): __tablename__ = 'comps' id = Column(Integer, primary_key=True) buyer_id = Column(None, ForeignKey('users.id')) user_id = Column(None, ForeignKey('users.id')) buyer = relation(User, backref=backref('buys', order_by=id)) user = relation(User, backref=backref('usings', order_by=id)) Of course, it cannot run. This is the backtrace: File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/state.py", line 71, in initialize_instance fn(self, instance, args, kwargs) File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/mapper.py", line 1829, in _event_on_init instrumenting_mapper.compile() File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/mapper.py", line 687, in compile mapper._post_configure_properties() File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/mapper.py", line 716, in _post_configure_properties prop.init() File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/interfaces.py", line 408, in init self.do_init() File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/properties.py", line 716, in do_init self._determine_joins() File "/Library/Python/2.6/site-packages/SQLAlchemy-0.5.8-py2.6.egg/sqlalchemy/orm/properties.py", line 806, in _determine_joins "many-to-many relation, 'secondaryjoin' is needed as well." % (self)) sqlalchemy.exc.ArgumentError: Could not determine join condition between parent/child tables on relation Package.maintainer. Specify a 'primaryjoin' expression. If this is a many-to-many relation, 'secondaryjoin' is needed as well. There's two foreign keys in class Computer, so the relation() callings cannot determine which one should be used. I think I must use extra arguments to specify it, right? And howto? Thanks

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  • JPA : many-to-many - only one foreign key in the association table

    - by Julien
    Hi, I mapped two classes in a ManyToMany association with these annotations : @Entity @Inheritance(strategy=InheritanceType.TABLE_PER_CLASS) public abstract class TechnicalItem extends GenericBusinessObject implements Resumable{ @SequenceGenerator(name="TECHNICAL_ITEM_ID_GEN", sequenceName="TECHNICAL_ITEM_ID_SEQ") @Id @Column(name = "\"ID\"", nullable = false) @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "TECHNICAL_ITEM_ID_GEN") private int id; @ManyToMany(mappedBy = "referencePerformanceItems", fetch=FetchType.LAZY) private List testingRates; } @Entity @DiscriminatorValue("T") public class TestingRate extends Rate { @ManyToMany(fetch=FetchType.LAZY) @JoinTable(name="ecc.\"TESTING_RATE_TECHNICAL_ITEM\"", joinColumns = {@JoinColumn(name = "\"TESTING_RATE_ID\"")}, inverseJoinColumns = {@JoinColumn(name = "\"TECHNICAL_ITEM_ID\"")}) //@ManyToMany(mappedBy = "testingRates", fetch=FetchType.LAZY) private List referencePerformanceItems; } The sql generated for the association table creation is : create table ecc."TESTING_RATE_TECHNICAL_ITEM" ( "TESTING_RATE_ID" int4 not null, "TECHNICAL_ITEM_ID" int4 not null ); alter table ecc."TESTING_RATE_TECHNICAL_ITEM" add constraint FKC5D64DF6A2FE2698 foreign key ("TESTING_RATE_ID") references ecc."RATE"; There is no mention of the second foreign key "TECHNICAL_ITEM_ID" (the second part of the composite foreign key which should be in the association table). Is it a normal behaviour ? What should I do in the mapping if I want my 2 columns are 2 foreign keys referencing the primary keys of my 2 concerned tables. I use a PostGreSQL database and Hibernate as JPA provider. Thanks, Julien

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  • vant view dataset with microsoft report viewer

    - by Tan
    I have a dataset, the dataset is using a stored procedur to fetch data. i have filled the dataset and everythings is okej.When iam using the debug i can se that the dataset is not empty. but i cant view it with the microsoft report viewer. here is my code please help. private void frmPrint_Load(object sender, EventArgs e) { this.reportViewer1.RefreshReport(); reportViewer1.LocalReport.DataSources.Clear(); GetCauseMachineMatrixTableAdapter adapter = new GetCauseMachineMatrixTableAdapter(); QpNibrolDataSet dataset = new QpNibrolDataSet(); adapter.Fill(dataset.GetCauseMachineMatrix, this.start, this.end); DataTable DT = dataset.Tables[0]; ReportDataSource reportdatasource = new ReportDataSource(); reportdatasource.Name = "RDS_NAME"; reportdatasource.Value = DT; reportViewer1.LocalReport.DataSources.Add(reportdatasource); reportViewer1.LocalReport.Refresh(); reportViewer1.RefreshReport(); } the form is saying "The source of the report definition is not been specified" what im i doing wrong. Idont use a rdlc because when iam trying to view my dataset no columms name show because the Stored procedur i am using requires Parameters. please advice and help my thank you

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  • maintaining a large list in python

    - by Oren
    I need to maintain a large list of python pickleable objects that will quickly execute the following algorithm: The list will have 4 pointers and can: Read\Write each of the 4 pointed nodes Insert new nodes before the pointed nodes Increase a pointer by 1 Pop nodes from the beginning of the list (without overlapping the pointers) Add nodes at the end of the list The list can be very large (300-400 MB), so it shouldnt be contained in the RAM. The nodes are small (100-200 bytes) but can contain various types of data. The most efficient way it can be done, in my opinion, is to implement some paging-mechanism. On the harddrive there will be some database of a linked-list of pages where in every moment up to 5 of them are loaded in the memory. On insertion, if some max-page-size was reached, the page will be splitted to 2 small pages, and on pointer increment, if a pointer is increased beyond its loaded page, the following page will be loaded instead. This is a good solution, but I don't have the time to write it, especially if I want to make it generic and implement all the python-list features. Using a SQL tables is not good either, since I'll need to implement a complex index-key mechanism. I tried ZODB and zc.blist, which implement a BTree based list that can be stored in a ZODB database file, but I don't know how to configure it so the above features will run in reasonable time. I don't need all the multi-threading\transactioning features. No one else will touch the database-file except for my single-thread program. Can anyone explain me how to configure the ZODB\zc.blist so the above features will run fast, or show me a different large-list implementation?

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  • How effective can this Tagging solution be?

    - by Pablo
    Im working on an image sharing site and want to implement tagging for the images. I've read Questions #20856 and #2504150 I have few concerns with the approach on the questions above. First of all it looks easy to link an image to a tag. However getting images by tag relation is not as easy. Not easy because you will have to get the image-to-tag relation from one table and then make a big query with a bunch of OR statements( one OR for every image). Before i even research the tagging topic i started testing the following method: This tables as examples: Table: Image Columns: ItemID, Title, Tags Table: Tag Columns: TagID, Name The Tags column in the Image table takes a string with multiple tagID from the Tag table enclosed by dashes(-). For example: -65-25-105- Links an image with the TagID 65,25 and 105. With this method i find it easier to get images by tag as i can get the TagID with one query and get all the images with another simple query like: SELECT * FROM Image WHERE Tags LIKE %-65-% So if i use this method for tagging, How effective this is? Is querying by LIKE %-65-% a slow process? What problems can i face in the future?

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  • Manipulating columns of numbers in elisp

    - by ~unutbu
    I have text files with tables like this: Investment advisory and related fees receivable (161,570 ) (71,739 ) (73,135 ) Net purchases of trading investments (93,261 ) (30,701 ) (11,018 ) Other receivables 61,216 (10,352 ) (69,313 ) Restricted cash 20,658 (20,658 ) - Other current assets (39,643 ) 14,752 64 Other non-current assets 71,896 (26,639 ) (26,330 ) Since these are accounting numbers, parenthesized numbers indicate negative numbers. Dashes represent 0 or no number. I'd like to be able to mark a rectangular region such as third column above, call a function (format-column), and automatically have (-73135-11018-69313+64-26330)/1000 sitting in my kill-ring. Even better would be -73.135-11.018-69.313+0.064-26.330 but I couldn't figure out a way to transform 64 -- 0.064. This is what I've come up with: (defun format-column () "format accounting numbers in a rectangular column. format-column puts the result in the kill-ring" (interactive) (let ((p (point)) (m (mark)) ) (copy-rectangle-to-register 0 (min m p) (max m p) nil) (with-temp-buffer (insert-register 0) (goto-char (point-min)) (while (search-forward "-" nil t) (replace-match "" nil t)) (goto-char (point-min)) (while (search-forward "," nil t) (replace-match "" nil t)) (goto-char (point-min)) (while (search-forward ")" nil t) (replace-match "" nil t)) (goto-char (point-min)) (while (search-forward "(" nil t) (replace-match "-" nil t) (just-one-space) (delete-backward-char 1) ) (goto-char (point-min)) (while (search-forward "\n" nil t) (replace-match " " nil t)) (goto-char (point-min)) (kill-new (mapconcat 'identity (split-string (buffer-substring (point-min) (point-max))) "+")) (kill-region (point-min) (point-max)) (insert "(") (yank 2) (goto-char (point-min)) (while (search-forward "+-" nil t) (replace-match "-" nil t)) (goto-char (point-max)) (insert ")/1000") (kill-region (point-min) (point-max)) ) ) ) (global-set-key "\C-c\C-f" 'format-column) Although it seems to work, I'm sure this function is poorly coded. The repetitive calls to goto-char, search-forward, and replace-match and the switching from buffer to string and back to buffer seems ugly and inelegant. My entire approach may be wrong-headed, but I don't know enough elisp to make this more beautiful. Do you see a better way to write format-column, and/or could you make suggestions on how to improve this code?

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  • Database structure - is mySQL the right choice?

    - by Industrial
    Hi everyone, We are currently planning the database structure of a quite complex e-commerce web app that has flexibility as it's main cornerstone. Our app features a large amount of data (products) and we have run into a slight headache trying to keep performance high without compromizing normalization rules in the database, or leaving our highly beloved flexibility concept behind when integrating product options (also widely known as product attributes or parameters). Based on various references and sources available, we have made up lists on pros and cons of all major and well known database patterns to solve this. After comparing these, we have come up with two final alternatives: EAV (Entity-attribute-value model) : Pros: Database is used for all sorting. Cons: All related queries will include a number of joins between multiple tables in order to complete the collection of data. SLOB (Serialized LOB, also known as Facade?) : Pros: Very flexible. Keeping the number of necessary joins low compared to a EAV design pattern. Easy to update/add/remove data from each product. Cons: All sorting will be done by the application instead of the database. Will use lots of performance (memory?) when big datasets is processed by a large number of users. Our main questions: Which pattern/structure would you use, or maybe even a different solution? Is there better databases besides mySQL available nowadays to accomplish what we want? Thanks a lot! Reference: http://stackoverflow.com/questions/695752/product-table-many-kinds-of-product-each-product-has-many-parameters

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  • Invoice & Invoice lines: How do you store customer address information?

    - by elviejo
    Hi I'm developing an invoicing application. So the general idea is to have two tables: Invoice (ID, Date, CustomerAddress, CustomerState, CustomerCountry, VAT, Total); InvoiceLine (Invoice_ID, ID, Concept, Units, PricePerUnit, Total); As you can see this basic design leads to a lot of repetiton of records where the client will have the same addrres, state and country. So the alternative is to have an address table and then make a relationship Address<-Invoice. However I think that an invoice is immutable document and should be stored just the way it was first made. Sometimes customers change their addresses, or states and if it was coming from an Address catalog that will change all the previously made invoices. So What is your experience? How is the customer address stored in an invoice? In the Invoice table? an Address Table? or something else? Can you provide pointers to a book, article or document where this is discussed in further detail?

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