Search Results

Search found 13723 results on 549 pages for 'constraint programming'.

Page 309/549 | < Previous Page | 305 306 307 308 309 310 311 312 313 314 315 316  | Next Page >

  • Oracle global lock across process

    - by Jimm
    I would like to synchronize access to a particular insert. Hence, if multiple applications execute this "one" insert, the inserts should happen one at a time. The reason behind synchronization is that there should only be ONE instance of this entity. If multiple applications try to insert the same entity,only one should succeed and others should fail. One option considered was to create a composite unique key, that would uniquely identify the entity and rely on unique constraint. For some reasons, the dba department rejected this idea. Other option that came to my mind was to create a stored proc for the insert and if the stored proc can obtain a global lock, then multiple applications invoking the same stored proc, though in their seperate database sessions, it is expected that the stored proc can obtain a global lock and hence serialize the inserts. My question is it possible to for a stored proc in oracle version 10/11, to obtain such a lock and any pointers to documentation would be helpful.

    Read the article

  • Grails Duplicate Exception handling

    - by Srinath
    Hi, How to catch duplicate key exceptions in Grails . when trying to save existing integer for a unique column constraint, the error is generating while saving/updating a record . Also used try{ object.save(flush:true) }catch(org.springframework. dao.DataIntegrityViolationException e){ println e.message }catch(org.hibernate.exception.ConstraintViolationException ex){ println e.message }catch(Exception e){ println e.message } But unable to catch this issue . 23:41:13,265 ERROR [JDBCExceptionReporter:101] Duplicate entry '1' for key 2 23:41:13,281 ERROR [AbstractFlushingEventListener:324] Could not synchronize database state with session org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) Could you please share the solution to solve this .

    Read the article

  • 2-Version software: Best VCS approach?

    - by Tom R
    I suppose I'd better explain my situation: I'm in the process of developing some software, and I'm at the stage where I'd like to split my project into two branches which differ in features. It so happens that this application is an Android application which I will be deploying on the Market, which has the constraint that every app must have a unique package identifier (sensible, no?). My current approach has been to clone the git repo of my original project, but this causes issues with package names. I want the system to be robust enough so that a bugfix/new feature on one branch will merge into another branch, but only when I want it to. Does anyone have any suggestions?

    Read the article

  • Weird use of generics

    - by Karl Trumstedt
    After a bit of programming one of my classes used generics in a way I never seen before. I would like some opinions of this, if it's bad coding or not. abstract class Base<T> : where T : Base<T> { // omitted methods and properties. virtual void CopyTo(T instance) { /*code*/ } } class Derived : Base<Derived> { override void CopyTo(Derived instance) { base.CopyTo(instance); // copy remaining stuff here } } is this an OK use of generics or not? I'm mostly thinking about the constraint to "itself". I sometimes feel like generics can "explode" to other classes where I use the Base class.

    Read the article

  • ImageMagick - how to enforce min/max heights/widths?

    - by Henryh
    Using ImageMagick, how can I resize an image to have a minimum: height of 150px width of 200px and also have a maximum: height of 225px width of 275px UPDATE: In case it helps, here's a further explanation of what I'm experiencing. I have a buch of images with all different ratio dimensions. Some images have 1:5 height/width ratios. Some have 5:1 height/width ratios. So that I want to do is set that a minimum height/width size for the image but also don't want the image size to be larger than a particular size. If I need to apply white padding to an image to make it fit within my constraint so that I don't have to distort the image, I'd like to do so.

    Read the article

  • How do I truncate a .NET string?

    - by Steve Guidi
    I apologize for such a question that likely has a trivial solution, but I strangely could not find a concise API for this problem. Essentially, I would like to truncate a string such that it its length is not longer than a given value. I am writing to a database table and want to ensure that the values I write meet the constraint of the column's datatype. For instance, it would be nice if I could write the following: string NormalizeLength(string value, int maxLength) { return value.Substring(0, maxLength); } Unfortunately, this raises an exception because maxLength exceeds the string boundaries. Of course, I could write a function like the following, but I was hoping that something like this already exists. string NormalizeLength(string value, int maxLength) { return value.Length <= maxLength ? value : value.Substring(0, maxLength); } Where is the elusive API that performs this task? Is there one?

    Read the article

  • Question About DateCreated and DateModified Columns - SQL Server

    - by user311509
    CREATE TABLE Customer ( customerID int identity (500,20) CONSTRAINT . . dateCreated datetime DEFAULT GetDate() NOT NULL, dateModified datetime DEFAULT GetDate() NOT NULL ); When i insert a record, dateCreated and dateModified gets set to default date/time. When i update/modify the record, dateModified and dateCreated remains as is? What should i do? Obviously, i need to dateCreated value to remain as was inserted the first time and dateModified keeps changing when a change/modification occurs in the record fields. In other words, can you please write a sample quick trigger? I don't know much yet...

    Read the article

  • A table that has relation to itself issue

    - by Mostafa
    Hi , I've defined table with this schema : CREATE TABLE [dbo].[Codings]( [Id] [int] IDENTITY(1,1) NOT NULL, [ParentId] [int] NULL, [CodeId] [int] NOT NULL, [Title] [nvarchar](50) COLLATE Arabic_CI_AI NOT NULL, CONSTRAINT [PK_Codings] PRIMARY KEY CLUSTERED ( [Id] ASC )WITH (IGNORE_DUP_KEY = OFF) ON [PRIMARY] ) ON [PRIMARY] And fill it up with data like this : Id ParentId CodeId Title ----------- ----------- ----------- ---------- 1 NULL 0 Gender 2 1 1 Male 3 1 2 Female 4 NULL 0 Educational Level 5 4 1 BS 6 4 2 MS 7 4 3 PHD Now , I'm looking for a solution , in order , When i delete a record that is parent ( like Id= 1 or 4 ), It delete all child automatically ( all records that their ParentId is 1 or 4 ) . I supposed i can do it via relation between Id and Parent Id ( and set cascade for delete rule ) , But when i do that in MMS , the Delete Rule or Update Rule in Properties is disabled . My question is , What can i do to accomplish this ? Thank you

    Read the article

  • Migrate a Django project from MySQL to Oracle

    - by pablo
    Hi, I have a Django1.1 project that works with a legacy MySQL db. I'm trying to migrate this project to Oracle (xe and 11g). We have two options for the migration: - Use SQL developer to create a migration sql script. - Use Django fixtures. The schema created with the sql script from sql developer doesn't match the schema created from syncdb. For example, Django expects TIMESTAMP columns while sql developer creates DATE columns. Using syncdb with Django fixtures could be great but when trying to load the MySQL fixtures into Oracle, after using syncdb, I'm getting: IntegrityError: ORA-00001: unique constraint (USER.SYS_C004253) violated How can I find what part create the integrity error? Thanks

    Read the article

  • How to persist non-trivial fields in Play Framework

    - by AlexR
    I am trying to persist complex objects using Ebeans in Play Framework (2.03). In particular, I've created a class that contains a field of type weka.classifier.Classifier (Weka is a popular machine learning library - see http://weka.sourceforge.net/doc/weka/classifiers/Classifier.html). Classifier implements Serializeable so I hoped that I can get away with something like @Entity @Table(name = "classifiers") public class ClassifierData extends Model { @Id public Long id; public Classifier classifier; } However, the Evolutions script suggests the following database structure: create table classifiers ( id bigint auto_increment not null, constraint pk_classifiers primary key (id)) ) In other words, it ignores the field of type Classifier. (The database is MySQL if it makes any difference) What should I do to store complex serializeable objects using Ebean/Evolutions/PlayFramework?

    Read the article

  • Mapping one to one foreign key relationships in Entity Framework 4.0?

    - by John K.
    Hello all, I'm sure I'm missing something very simple, but let's say I have two entities, Employee and EmployeeType. Employee type would contain values like 'Full time', 'Contractor', 'Intern', etc. An Employee entity would contain one, and only one EmployeeType value. So I am designing a new .edmx model using the Model-First approach and generating my actual sql server data schema from the model. I want to add an integer type foreign key id into my Employee entity, EmployeeTypeId, which will map to the primary key of the EmployeeType entity. So I've gone ahead and done that in my Employee entity. Where I'm stuck is how, though the Entity Framework designer, to enforce the 1:1 referential constraint on that EmployeeTypeId property? Or does the EF handle that automatically behind the scenes? thanks in advance, John

    Read the article

  • c# Generics problem

    - by UpTheCreek
    Can anyone tell me why this does not work? I would have thought the constraint would make it valid. public class ClassA<T> where T : ICommon { public ClassA() { ClassB b = new b(); IEnumerable<T> alist = new IList<T>; b.items = alist; //Error: cannot convert from IEnumerable<T> to IEnumerable<ICommon>' } } public class ClassB { IEnumerable<ICommon> items { get; set;} .... }

    Read the article

  • Auto Generated - CREATE Table Script in SQL 2008 throws error

    - by jack
    I scripted the tables in my dev database using SQL 2008 - generate scripts option (Datbase-right click-Tasks-Generate Scripts) and ran it on the staging database, but the script throws the below error for each table Msg 102, Level 15, State 1, Line 1 Incorrect syntax near '('. Msg 319, Level 15, State 1, Line 15 Incorrect syntax near the keyword 'with'. If this statement is a common table expression, an xmlnamespaces clause or a change tracking context clause, the previous statement must be terminated with a semicolon. Below is the script for one of my table ALTER TABLE [dbo].[Customer]( [CustomerID] [int] IDENTITY(1,1) NOT NULL, [FirstName] [nvarchar](500) NULL, [LastName] [nvarchar](500) NULL, [DateOfBirth] [datetime] NULL, [EmailID] [nvarchar](200) NULL, [ContactForOffers] [bit] NULL, CONSTRAINT [PK_Customer] PRIMARY KEY CLUSTERED ( [CustomerID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] GO Any help will be much appreciated.

    Read the article

  • Triangular bounding volumes

    - by Cheery
    I've come up with an alternative for beziers that might be easier to ray-trace, perhaps even though a plain vertex shader. Though there's missing a piece. I need to find the parametric surface equation from the surface normals I have for edge vertices. I also have to know it's peak and valley so I can constraint the depth of my bounding triangle. Image explains the overall idea: I build a bounding-volume from a control triangle. Then apply a function to each parametric coordinate of the triangle (s+t+u=1 where s,t,u = 0) to get the height coordinate for that certain point. Simply put, it produces a procedurally generated height-map for the triangle's surface. I just need to find a function that generates the height-map so I can make it work.

    Read the article

  • Why does SQL Server keep throwing exceptions?

    - by Augusto Càzares
    I have my project in .NET that uses a database in SQL Server. I'm using Linq-to-SQL, sometimes when the project throws me an exception (Constraint) in a part of the project this same error keeps showing in other part of the project when I do another thing with the database. Like when I do an insertion and I had before an exception on delete the insertion throws me the delete exception, and it remains this way until I close and open again the project. My major problem is when this happen in my online project, this error in my project causes me problems in the project I'm testing online (I use the same database). I don't know if this exception is on the memory or something but its have been causing me a lot of headaches.

    Read the article

  • Making sure unsigned int/long always execute in checked context in C#

    - by theburningmonk
    Has anyone found it strange that the default context for uint and ulong is unchecked rather than checked considering that they are meant to represent values that can never be negative? So if some code is trying to violate that constraint it seems to me the natural and preferred behaviour would be to throw an exception rather than returning the max value instead (which can easily leave important pieces of data in an invalid state and impossible to revert..). Is there an existing attribute which can be applied to either class/assembly so that it always performs arithmetic operations in a checked context? I was thinking of writing one myself (as an aspect using PostSharp) but would be great if there's one already. Many thanks,

    Read the article

  • How to support both DataContractSerializer and XMLSerializer for the same contract on the same host?

    - by Sly
    In our production environment, our WCF services are serialized with the XMLSerializer. To do so our service interfaces have the [XMLSerializerFormat] attribute. Now, we need to change to DataContractSerializer but we must stay compatible with our existing clients. Therefore, we have to expose each service with both serializers. We have one constraint: we don't want to redefine each contract interface twice, we have 50 services contract interfaces and we don't want to have IIncidentServiceXml IIncidentServiceDCS IEmployeeServiceXml IEmployeeServiceDCS IContractServiceXml IContractServiceDCS How can we do that? This is a description of what we have tried so far but I'm willing to try completely different approaches: We tried to create all the endpoints by code in our own ServiceHostFactory class. Basically we create each endpoint twice. The problem is that at runtime, WCF complains that the service has two endpoints with the same contact name but with different ContractDescription instances. The message says we should use different contract names or reuse the same ContractDescription instance.

    Read the article

  • Issues with SharePoint 2010 Development

    - by Rahul Soni
    I am planning to use my laptop for SharePoint 2010 development and I have only 4 GB RAM which is not even upgradable. Just because of RAM constraint, my VS 2010 keeps crawling if I try to run it along with SharePoint 2010 on the same machine. Hence, I've reformatted my machine and looking for alternate solutions until I get a new laptop. Currently, I have installed VS 2010 ONLY on my laptop and wanted to create an empty SharePoint project. Once done with my project, I want to deploy it on a different machine (which is a 4GB RAM machine as well, but contains only SharePoint 2010). I thought this will work and give me a bit of breather if everything is configured well. Unfortunately, when I tried creating a new SharePoint Empty Project in VS 2010, it says... A SharePoint server is not installed on this computer. A SharePoint server must be installed to work with SharePoint projects. Is there a way out?

    Read the article

  • mysql foreign key problem.

    - by JP19
    Hi, What is wrong with the foreign key addition here: mysql> create table notes ( id int (11) NOT NULL auto_increment PRIMARY KEY, note_type_id smallint(5) NOT NULL, data TEXT NOT NULL, created_date datetime NOT NULL, modified_date timestamp NOT NULL on update now()) Engine=InnoDB; Query OK, 0 rows affected (0.08 sec) mysql> create table notetypes ( id smallint (5) NOT NULL auto_increment PRIMARY KEY, type varchar(255) NOT NULL UNIQUE) Engine=InnoDB; Query OK, 0 rows affected (0.00 sec) mysql> alter table `notes` add constraint foreign key(`note_type_id`) references `notetypes`.`id` on update cascade on delete restrict; ERROR 1005 (HY000): Can't create table './admin/#sql-43e_b762.frm' (errno: 150) Thanks JP

    Read the article

  • Hibernate doesn't generate cascade

    - by Shervin
    Hi. I have a set hibernate.hbm2ddl.auto to create so that Hibernate creates the tables in mysql for me. However, it doesn't seem that hibernate correctly adds Cascade on the references in the table. It does however work when I for instance delete a row, and I have a delete cascade as hibernate annotation. So I guess that means that Hibernate reads the annoation on runtime, and perform cascading manually? Is that normal behavior? For instance: @Entity class Report { @OneToOne(cascade = CascadeType.ALL) public File getPdf() { return pdf; } } Here I have set cascade to ALL. However, when running show create table Report Report | CREATE TABLE `Report` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `pdf_id` bigint(20) DEFAULT NULL, PRIMARY KEY (`id`), KEY `FK91B14154FDE6543A` (`pdf_id`), CONSTRAINT `FK91B14154FDE6543A` FOREIGN KEY (`pdf_id`) REFERENCES `File` (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | It doesn't say anything about cascading other then the foreign key. In my opinion, it should have added the ON DELETE CASCADE ON DELETE UPDATE

    Read the article

  • Data Access from single table in sql server 2005 is too slow

    - by Muhammad Kashif Nadeem
    Following is the script of table. Accessing data from this table is too slow. SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO CREATE TABLE [dbo].[Emails]( [id] [int] IDENTITY(1,1) NOT NULL, [datecreated] [datetime] NULL CONSTRAINT [DF_Emails_datecreated] DEFAULT (getdate()), [UID] [nvarchar](250) COLLATE Latin1_General_CI_AS NULL, [From] [nvarchar](100) COLLATE Latin1_General_CI_AS NULL, [To] [nvarchar](100) COLLATE Latin1_General_CI_AS NULL, [Subject] [nvarchar](max) COLLATE Latin1_General_CI_AS NULL, [Body] [nvarchar](max) COLLATE Latin1_General_CI_AS NULL, [HTML] [nvarchar](max) COLLATE Latin1_General_CI_AS NULL, [AttachmentCount] [int] NULL, [Dated] [datetime] NULL ) ON [PRIMARY] Following query takes 50 seconds to fetch data. select id, datecreated, UID, [From], [To], Subject, AttachmentCount, Dated from emails If I include Body and Html in select then time is event worse. indexes are on: id unique clustered From Non unique non clustered To Non unique non clustered Tabls has currently 180000+ records. There might be 100,000 records each month so this will become more slow as time will pass. Does splitting data into two table will solve the problem? What other indexes should be there?

    Read the article

  • Copying Data between table without identity column

    - by user668479
    I have two table and I need to copy the data across from SRCServiceUsers to Clients Everytime i run it I get the following: Violation of PRIMARY KEY constraint 'PK_Clients'. Cannot insert duplicate key in object 'dbo.Clients'. The statement has been terminated. The Primary key ClientId field is not an identity column and therefore requires filling To date I have the following insert into Clients( ClientID, Title, Forenames, FamilyName, [Address], Town, County, PostCode, PhoneNumber, StartDate) SELECT ( Select Max(Clients.ClientID)+ 1, SRCServiceUsers.Title, SRCServiceUsers.[First Names], SRCServiceUsers.Surname, --BUILD UP MUITIPLE COLUMNS SRCServiceUsers.[Property Name] + ', ' + SRCServiceUsers.Street + ', ' + SRCServiceUsers.Suburb as [Address], SRCServiceUsers.Town, SRCServiceUsers.County, SRCServiceUsers.Postcode, SRCServiceUsers.Telephone, SRCServiceUsers.[Start Date] From srcsERVICEuSERS How can i autoincrement the PK field - CLientID when inserting the data? Many thanks Andrew

    Read the article

  • Social Network directed Graph Library? .NET

    - by MRFerocius
    Hello everybody, I am on a project where I have multiple users of a portal and they are connected to other users of the portal, now we are asked to draw a "Social Network" relationship graph to see the relationships. The constraint is that this graph has to be seen on the WEB BROWSER. The graph has to be something like: Is there any C# library or component to draw this type of graphs? We have already checked these: http://flare.prefuse.org/ http://www.yworks.com/en/products_yfiles_practicalinfo_gallery.html .NET graph library around? http://quickgraph.codeplex.com/ https://graphsharp.codeplex.com/ http://research.microsoft.com/en-us/downloads/f1303e46-965f-401a-87c3-34e1331d32c5/default.aspx http://sourceforge.net/projects/zedgraph/ But I want to check if you already used some other and your feedback... Thanks in advanced!

    Read the article

  • How to specify a different column for a @Inheritance JPA annotation

    - by Cue
    @Entity @Inheritance(strategy = InheritanceType.JOINED) public class Foo @Entity @Inheritance(strategy = InheritanceType.JOINED) public class BarFoo extends Foo mysql> desc foo; +---------------+-------------+ | Field | Type | +---------------+-------------+ | id | int | +---------------+-------------+ mysql> desc barfoo; +---------------+-------------+ | Field | Type | +---------------+-------------+ | id | int | | foo_id | int | | bar_id | int | +---------------+-------------+ mysql> desc bar; +---------------+-------------+ | Field | Type | +---------------+-------------+ | id | int | +---------------+-------------+ Is it possible to specify column barfo.foo_id as the joined column? Are you allowed to specify barfoo.id as BarFoo's @Id since you are overriding the getter/seeter of class Foo? I understand the schematics behind this relationship (or at least I think I do) and I'm ok with them. The reason I want an explicit id field for BarFoo is exactly because I want to avoid using a joined key (foo _id, bar _id) when querying for BarFoo(s) or when used in a "stronger" constraint. (as Ruben put it)

    Read the article

  • how to use use case relations - uml

    - by joao alves
    Heys guys! Im have been study UML and im trying to to design the use case diagram of a problem. Lets supose my app consists in this: Two Requesites: - create teams - create players This is the deal: A user can create a team, and after create a team he can create players for that team(not required). But in this app there are multiple users, and a user can create a team and other user can create players. The only constraint is that to create players must exist alreay a team. I research and i end up a little confuse. If i get the concepts of relations on use case diagrams right, i think i should have the folowwing two use cases: [use case - create team] <-------extends---- [use case - create player] I need opinions,Is this the proper solution? or should i have two not related use cases? Thanks in advance, and im sorry my english.

    Read the article

< Previous Page | 305 306 307 308 309 310 311 312 313 314 315 316  | Next Page >