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  • Specifying Multiplicity in a Visio Database (ERD) Diagram

    - by Nitrodist
    Is there a way to manually edit the cardinality/multiplicity symbols on the end of a database ERD made in Visio? The category I'm using is in Visio 2003 under Database -> Database Model Diagram I want to be able to go from something like this: To this: The second graphic was done by manually adding the numbers, but I would prefer to just do it in Visio. Is there any way of accomplishing this?

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  • Specifying Multiplicity in a Visio Database (ERD) Diagram

    - by Nitrodist
    Is there a way to manually edit the cardinality/multiplicity symbols on the end of a database ERD made in Visio? The category I'm using is in Visio 2003 under Database -> Database Model Diagram I want to be able to go from something like this: To this: The second graphic was done by manually adding the numbers, but I would prefer to just do it in Visio. Is there any way of accomplishing this?

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  • Unique Keys not recognized by Entity Framework

    - by David Pfeffer
    I have two tables, Reports and Visualizations. Reports has a field, VisualizationID, which points to Visualization's field of the same name via a foreign key. It also has a unique key declared on the field. VisualizationID is not nullable. This means the relationship has to be 0..1 to 1, because every Reports record must have a unique, not null Visualizations record associated with it. The Entity Framework doesn't see it this way. I'm getting the following error: Error 113: Multiplicity is not valid in Role 'Report' in relationship 'FK_Reports_Visualizations'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be *. What's the problem here? How can I make the EF recognize the proper relationship multiplicity?

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  • Problems with inheritance query view and one to many association in entity framework 4

    - by Kazys
    Hi, I have situation in with I stucked and don't know way out. The problem is in my bigger model, but I have made small example which shows the same problem. I have 4 tables. I called them SuperParent, NamedParent, TypedParent and ParentType. NamedParent and TypedParent derives from superParent. TypedParent has one to many association with ParentType. I describe mapping for entities using queryView. The problem is then I want to get TypedParents and Include ParentType I get the following exception: An error occurred while preparing the command definition. See the inner exception for details. --- System.ArgumentException: The ResultType of the specified expression is not compatible with the required type. The expression ResultType is 'Transient.reference[PasibandymaiModel.SuperParent]' but the required type is 'Transient.reference[PasibandymaiModel.TypedParent]'. Parameter name: arguments[1] To get TypedParents I use following code: context.SuperParent.OfType().Include("ParentType"); my edmx file: <edmx:Edmx Version="2.0" xmlns:edmx="http://schemas.microsoft.com/ado/2008/10/edmx"> <!-- EF Runtime content --> <edmx:Runtime> <!-- SSDL content --> <edmx:StorageModels> <Schema Namespace="PasibandymaiModel.Store" Alias="Self" Provider="System.Data.SqlClient" ProviderManifestToken="2005" xmlns:store="http://schemas.microsoft.com/ado/2007/12/edm/EntityStoreSchemaGenerator" xmlns="http://schemas.microsoft.com/ado/2009/02/edm/ssdl"> <EntityContainer Name="PasibandymaiModelStoreContainer"> <EntitySet Name="NamedParent" EntityType="PasibandymaiModel.Store.NamedParent" store:Type="Tables" Schema="dbo" /> <EntitySet Name="ParentType" EntityType="PasibandymaiModel.Store.ParentType" store:Type="Tables" Schema="dbo" /> <EntitySet Name="SuperParent" EntityType="PasibandymaiModel.Store.SuperParent" store:Type="Tables" Schema="dbo" /> <EntitySet Name="TypedParent" EntityType="PasibandymaiModel.Store.TypedParent" store:Type="Tables" Schema="dbo" /> <AssociationSet Name="fk_NamedParent_SuperParent" Association="PasibandymaiModel.Store.fk_NamedParent_SuperParent"> <End Role="SuperParent" EntitySet="SuperParent" /> <End Role="NamedParent" EntitySet="NamedParent" /> </AssociationSet> <AssociationSet Name="fk_TypedParent_ParentType" Association="PasibandymaiModel.Store.fk_TypedParent_ParentType"> <End Role="ParentType" EntitySet="ParentType" /> <End Role="TypedParent" EntitySet="TypedParent" /> </AssociationSet> <AssociationSet Name="fk_TypedParent_SuperParent" Association="PasibandymaiModel.Store.fk_TypedParent_SuperParent"> <End Role="SuperParent" EntitySet="SuperParent" /> <End Role="TypedParent" EntitySet="TypedParent" /> </AssociationSet> </EntityContainer> <EntityType Name="NamedParent"> <Key> <PropertyRef Name="ParentId" /> </Key> <Property Name="ParentId" Type="int" Nullable="false" /> <Property Name="Name" Type="nvarchar" Nullable="false" MaxLength="100" /> </EntityType> <EntityType Name="ParentType"> <Key> <PropertyRef Name="ParentTypeId" /> </Key> <Property Name="ParentTypeId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> <Property Name="Name" Type="nvarchar" MaxLength="100" /> </EntityType> <EntityType Name="SuperParent"> <Key> <PropertyRef Name="ParentId" /> </Key> <Property Name="ParentId" Type="int" Nullable="false" StoreGeneratedPattern="Identity" /> <Property Name="SomeAttribute" Type="nvarchar" Nullable="false" MaxLength="100" /> </EntityType> <EntityType Name="TypedParent"> <Key> <PropertyRef Name="ParentId" /> </Key> <Property Name="ParentId" Type="int" Nullable="false" /> <Property Name="ParentTypeId" Type="int" Nullable="false"/> </EntityType> <Association Name="fk_NamedParent_SuperParent"> <End Role="SuperParent" Type="PasibandymaiModel.Store.SuperParent" Multiplicity="1" /> <End Role="NamedParent" Type="PasibandymaiModel.Store.NamedParent" Multiplicity="0..1" /> <ReferentialConstraint> <Principal Role="SuperParent"> <PropertyRef Name="ParentId" /> </Principal> <Dependent Role="NamedParent"> <PropertyRef Name="ParentId" /> </Dependent> </ReferentialConstraint> </Association> <Association Name="fk_TypedParent_ParentType"> <End Role="ParentType" Type="PasibandymaiModel.Store.ParentType" Multiplicity="1" /> <End Role="TypedParent" Type="PasibandymaiModel.Store.TypedParent" Multiplicity="*" /> <ReferentialConstraint> <Principal Role="ParentType"> <PropertyRef Name="ParentTypeId" /> </Principal> <Dependent Role="TypedParent"> <PropertyRef Name="ParentTypeId" /> </Dependent> </ReferentialConstraint> </Association> <Association Name="fk_TypedParent_SuperParent"> <End Role="SuperParent" Type="PasibandymaiModel.Store.SuperParent" Multiplicity="1" /> <End Role="TypedParent" Type="PasibandymaiModel.Store.TypedParent" Multiplicity="0..1" /> <ReferentialConstraint> <Principal Role="SuperParent"> <PropertyRef Name="ParentId" /> </Principal> <Dependent Role="TypedParent"> <PropertyRef Name="ParentId" /> </Dependent> </ReferentialConstraint> </Association> <Function Name="ChildDelete" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ChildId" Type="int" Mode="In" /> </Function> <Function Name="ChildInsert" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="Name" Type="nvarchar" Mode="In" /> <Parameter Name="ParentId" Type="int" Mode="In" /> </Function> <Function Name="ChildUpdate" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ChildId" Type="int" Mode="In" /> <Parameter Name="ParentId" Type="int" Mode="In" /> <Parameter Name="Name" Type="nvarchar" Mode="In" /> </Function> <Function Name="NamedParentDelete" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentId" Type="int" Mode="In" /> </Function> <Function Name="NamedParentInsert" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="Name" Type="nvarchar" Mode="In" /> <Parameter Name="SomeAttribute" Type="nvarchar" Mode="In" /> </Function> <Function Name="NamedParentUpdate" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentId" Type="int" Mode="In" /> <Parameter Name="SomeAttribute" Type="nvarchar" Mode="In" /> <Parameter Name="Name" Type="nvarchar" Mode="In" /> </Function> <Function Name="ParentTypeDelete" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentTypeId" Type="int" Mode="In" /> </Function> <Function Name="ParentTypeInsert" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="Name" Type="nvarchar" Mode="In" /> </Function> <Function Name="ParentTypeUpdate" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentTypeId" Type="int" Mode="In" /> <Parameter Name="Name" Type="nvarchar" Mode="In" /> </Function> <Function Name="TypedParentDelete" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentId" Type="int" Mode="In" /> </Function> <Function Name="TypedParentInsert" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentTypeId" Type="int" Mode="In" /> <Parameter Name="SomeAttribute" Type="nvarchar" Mode="In" /> </Function> <Function Name="TypedParentUpdate" Aggregate="false" BuiltIn="false" NiladicFunction="false" IsComposable="false" ParameterTypeSemantics="AllowImplicitConversion" Schema="dbo"> <Parameter Name="ParentId" Type="int" Mode="In" /> <Parameter Name="SomeAttribute" Type="nvarchar" Mode="In" /> <Parameter Name="ParentTypeId" Type="int" Mode="In" /> </Function> </Schema> </edmx:StorageModels> <!-- CSDL content --> <edmx:ConceptualModels> <Schema Namespace="PasibandymaiModel" Alias="Self" xmlns:annotation="http://schemas.microsoft.com/ado/2009/02/edm/annotation" xmlns="http://schemas.microsoft.com/ado/2008/09/edm"> <EntityContainer Name="PasibandymaiEntities" annotation:LazyLoadingEnabled="true"> <EntitySet Name="ParentType" EntityType="PasibandymaiModel.ParentType" /> <EntitySet Name="SuperParent" EntityType="PasibandymaiModel.SuperParent" /> <AssociationSet Name="ParentTypeTypedParent" Association="PasibandymaiModel.ParentTypeTypedParent"> <End Role="ParentType" EntitySet="ParentType" /> <End Role="TypedParent" EntitySet="SuperParent" /> </AssociationSet> </EntityContainer> <EntityType Name="NamedParent" BaseType="PasibandymaiModel.SuperParent"> <Property Type="String" Name="Name" Nullable="false" MaxLength="100" FixedLength="false" Unicode="true" /> </EntityType> <EntityType Name="ParentType"> <Key> <PropertyRef Name="ParentTypeId" /> </Key> <Property Type="Int32" Name="ParentTypeId" Nullable="false" annotation:StoreGeneratedPattern="Identity" /> <Property Type="String" Name="Name" MaxLength="100" FixedLength="false" Unicode="true" /> <NavigationProperty Name="TypedParent" Relationship="PasibandymaiModel.ParentTypeTypedParent" FromRole="ParentType" ToRole="TypedParent" /> </EntityType> <EntityType Name="SuperParent" Abstract="true"> <Key> <PropertyRef Name="ParentId" /> </Key> <Property Type="Int32" Name="ParentId" Nullable="false" annotation:StoreGeneratedPattern="Identity" /> <Property Type="String" Name="SomeAttribute" Nullable="false" MaxLength="100" FixedLength="false" Unicode="true" /> </EntityType> <EntityType Name="TypedParent" BaseType="PasibandymaiModel.SuperParent"> <NavigationProperty Name="ParentType" Relationship="PasibandymaiModel.ParentTypeTypedParent" FromRole="TypedParent" ToRole="ParentType" /> <Property Type="Int32" Name="ParentTypeId" Nullable="false" /> </EntityType> <Association Name="ParentTypeTypedParent"> <End Type="PasibandymaiModel.ParentType" Role="ParentType" Multiplicity="1" /> <End Type="PasibandymaiModel.TypedParent" Role="TypedParent" Multiplicity="*" /> <ReferentialConstraint> <Principal Role="ParentType"> <PropertyRef Name="ParentTypeId" /> </Principal> <Dependent Role="TypedParent"> <PropertyRef Name="ParentTypeId" /> </Dependent> </ReferentialConstraint> </Association> </Schema> </edmx:ConceptualModels> <!-- C-S mapping content --> <edmx:Mappings> <Mapping Space="C-S" xmlns="http://schemas.microsoft.com/ado/2008/09/mapping/cs"> <EntityContainerMapping StorageEntityContainer="PasibandymaiModelStoreContainer" CdmEntityContainer="PasibandymaiEntities"> <EntitySetMapping Name="ParentType"> <QueryView> SELECT VALUE PasibandymaiModel.ParentType(tp.ParentTypeId, tp.Name) FROM PasibandymaiModelStoreContainer.ParentType AS tp </QueryView> </EntitySetMapping> <EntitySetMapping Name="SuperParent"> <QueryView> SELECT VALUE CASE WHEN (np.ParentId IS NOT NULL) THEN PasibandymaiModel.NamedParent(sp.ParentId, sp.SomeAttribute, np.Name) WHEN (tp.ParentId IS NOT NULL) THEN PasibandymaiModel.TypedParent(sp.ParentId, sp.SomeAttribute, tp.ParentTypeId) END FROM PasibandymaiModelStoreContainer.SuperParent AS sp LEFT JOIN PasibandymaiModelStoreContainer.NamedParent AS np ON sp.ParentId = np.ParentId LEFT JOIN PasibandymaiModelStoreContainer.TypedParent AS tp ON sp.ParentId = tp.ParentId </QueryView> <QueryView TypeName="PasibandymaiModel.TypedParent"> SELECT VALUE PasibandymaiModel.TypedParent(sp.ParentId, sp.SomeAttribute, tp.ParentTypeId) FROM PasibandymaiModelStoreContainer.SuperParent AS sp INNER JOIN PasibandymaiModelStoreContainer.TypedParent AS tp ON sp.ParentId = tp.ParentId </QueryView> <QueryView TypeName="PasibandymaiModel.NamedParent"> SELECT VALUE PasibandymaiModel.NamedParent(sp.ParentId, sp.SomeAttribute, np.Name) FROM PasibandymaiModelStoreContainer.SuperParent AS sp INNER JOIN PasibandymaiModelStoreContainer.NamedParent AS np ON sp.ParentId = np.ParentId </QueryView> </EntitySetMapping> </EntityContainerMapping> </Mapping> </edmx:Mappings> </edmx:Runtime> </edmx:Edmx> I have tried using AssociationSetMapping instead of using Association with ReferentialConstraint. But then couldn't insert related entities at once, becouse entity framework didn't provided entity key of inserted entities for related entities. Thanks for any idea

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  • How to map a 0..1 to 1 relationship in Entity Framework 3

    - by sako73
    I have two tables, Users, and Address. A the user table has a field that maps to the primary key of the address table. This field can be null. In plain english, Address exist independent of other objects. A user may be associated with one address. In the database, I have this set up as a foreign key relationship. I am attempting to map this relationship in the Entity Framework. I am getting errors on the following code: <Association Name="fk_UserAddress"> <End Role="User" Type="GenesisEntityModel.Store.User" Multiplicity="1"/> <End Role="Address" Type="GenesisEntityModel.Store.Address" Multiplicity="0..1" /> <ReferentialConstraint> <Principal Role="Address"> <PropertyRef Name="addressId"/> </Principal> <Dependent Role="User"> <PropertyRef Name="addressId"/> </Dependent> </ReferentialConstraint> </Association> It is giving a "The Lower Bound of the multiplicity must be 0" error. I would appreciate it if anyone could explain the error, and the best way to solve it. Thanks for any help.

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  • Entity Association Mapping with Code First Part 1 : Mapping Complex Types

    - by mortezam
    Last week the CTP5 build of the new Entity Framework Code First has been released by data team at Microsoft. Entity Framework Code-First provides a pretty powerful code-centric way to work with the databases. When it comes to associations, it brings ultimate flexibility. I’m a big fan of the EF Code First approach and am planning to explain association mapping with code first in a series of blog posts and this one is dedicated to Complex Types. If you are new to Code First approach, you can find a great walkthrough here. In order to build a solid foundation for our discussion, we will start by learning about some of the core concepts around the relationship mapping.   What is Mapping?Mapping is the act of determining how objects and their relationships are persisted in permanent data storage, in our case, relational databases. What is Relationship mapping?A mapping that describes how to persist a relationship (association, aggregation, or composition) between two or more objects. Types of RelationshipsThere are two categories of object relationships that we need to be concerned with when mapping associations. The first category is based on multiplicity and it includes three types: One-to-one relationships: This is a relationship where the maximums of each of its multiplicities is one. One-to-many relationships: Also known as a many-to-one relationship, this occurs when the maximum of one multiplicity is one and the other is greater than one. Many-to-many relationships: This is a relationship where the maximum of both multiplicities is greater than one. The second category is based on directionality and it contains two types: Uni-directional relationships: when an object knows about the object(s) it is related to but the other object(s) do not know of the original object. To put this in EF terminology, when a navigation property exists only on one of the association ends and not on the both. Bi-directional relationships: When the objects on both end of the relationship know of each other (i.e. a navigation property defined on both ends). How Object Relationships Are Implemented in POCO domain models?When the multiplicity is one (e.g. 0..1 or 1) the relationship is implemented by defining a navigation property that reference the other object (e.g. an Address property on User class). When the multiplicity is many (e.g. 0..*, 1..*) the relationship is implemented via an ICollection of the type of other object. How Relational Database Relationships Are Implemented? Relationships in relational databases are maintained through the use of Foreign Keys. A foreign key is a data attribute(s) that appears in one table and must be the primary key or other candidate key in another table. With a one-to-one relationship the foreign key needs to be implemented by one of the tables. To implement a one-to-many relationship we implement a foreign key from the “one table” to the “many table”. We could also choose to implement a one-to-many relationship via an associative table (aka Join table), effectively making it a many-to-many relationship. Introducing the ModelNow, let's review the model that we are going to use in order to implement Complex Type with Code First. It's a simple object model which consist of two classes: User and Address. Each user could have one billing address. The Address information of a User is modeled as a separate class as you can see in the UML model below: In object-modeling terms, this association is a kind of aggregation—a part-of relationship. Aggregation is a strong form of association; it has some additional semantics with regard to the lifecycle of objects. In this case, we have an even stronger form, composition, where the lifecycle of the part is fully dependent upon the lifecycle of the whole. Fine-grained domain models The motivation behind this design was to achieve Fine-grained domain models. In crude terms, fine-grained means “more classes than tables”. For example, a user may have both a billing address and a home address. In the database, you may have a single User table with the columns BillingStreet, BillingCity, and BillingPostalCode along with HomeStreet, HomeCity, and HomePostalCode. There are good reasons to use this somewhat denormalized relational model (performance, for one). In our object model, we can use the same approach, representing the two addresses as six string-valued properties of the User class. But it’s much better to model this using an Address class, where User has the BillingAddress and HomeAddress properties. This object model achieves improved cohesion and greater code reuse and is more understandable. Complex Types: Splitting a Table Across Multiple Types Back to our model, there is no difference between this composition and other weaker styles of association when it comes to the actual C# implementation. But in the context of ORM, there is a big difference: A composed class is often a candidate Complex Type. But C# has no concept of composition—a class or property can’t be marked as a composition. The only difference is the object identifier: a complex type has no individual identity (i.e. no AddressId defined on Address class) which make sense because when it comes to the database everything is going to be saved into one single table. How to implement a Complex Types with Code First Code First has a concept of Complex Type Discovery that works based on a set of Conventions. The convention is that if Code First discovers a class where a primary key cannot be inferred, and no primary key is registered through Data Annotations or the fluent API, then the type will be automatically registered as a complex type. Complex type detection also requires that the type does not have properties that reference entity types (i.e. all the properties must be scalar types) and is not referenced from a collection property on another type. Here is the implementation: public class User{    public int UserId { get; set; }    public string FirstName { get; set; }    public string LastName { get; set; }    public string Username { get; set; }    public Address Address { get; set; }} public class Address {     public string Street { get; set; }     public string City { get; set; }            public string PostalCode { get; set; }        }public class EntityMappingContext : DbContext {     public DbSet<User> Users { get; set; }        } With code first, this is all of the code we need to write to create a complex type, we do not need to configure any additional database schema mapping information through Data Annotations or the fluent API. Database SchemaThe mapping result for this object model is as follows: Limitations of this mappingThere are two important limitations to classes mapped as Complex Types: Shared references is not possible: The Address Complex Type doesn’t have its own database identity (primary key) and so can’t be referred to by any object other than the containing instance of User (e.g. a Shipping class that also needs to reference the same User Address). No elegant way to represent a null reference There is no elegant way to represent a null reference to an Address. When reading from database, EF Code First always initialize Address object even if values in all mapped columns of the complex type are null. This means that if you store a complex type object with all null property values, EF Code First returns a initialized complex type when the owning entity object is retrieved from the database. SummaryIn this post we learned about fine-grained domain models which complex type is just one example of it. Fine-grained is fully supported by EF Code First and is known as the most important requirement for a rich domain model. Complex type is usually the simplest way to represent one-to-one relationships and because the lifecycle is almost always dependent in such a case, it’s either an aggregation or a composition in UML. In the next posts we will revisit the same domain model and will learn about other ways to map a one-to-one association that does not have the limitations of the complex types. References ADO.NET team blog Mapping Objects to Relational Databases Java Persistence with Hibernate

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  • How can I find the shortest path between two subgraphs of a larger graph?

    - by Pops
    I'm working with a weighted, undirected multigraph (loops not permitted; most node connections have multiplicity 1; a few node connections have multiplicity 2). I need to find the shortest path between two subgraphs of this graph that do not overlap with each other. There are no other restrictions on which nodes should be used as start/end points. Edges can be selectively removed from the graph at certain times (as explained in my previous question) so it's possible that for two given subgraphs, there might not be any way to connect them. I'm pretty sure I've heard of an algorithm for this before, but I can't remember what it's called, and my Google searches for strings like "shortest path between subgraphs" haven't helped. Can someone suggest a more efficient way to do this than comparing shortest paths between all nodes in one subgraph with all nodes in the other subgraph? Or at least tell me the name of the algorithm so I can look it up myself? For example, if I have the graph below, the nodes circled in red might be one subgraph and the nodes circled in blue might be another. The edges would all have positive integer weights, although they're not shown in the image. I'd want to find whatever path has the shortest total cost as long as it starts at a red node and ends at a blue node. I believe this means the specific node positions and edge weights cannot be ignored. (This is just an example graph I grabbed off Wikimedia and drew on, not my actual problem.)

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  • Entity Framework One-To-One Mapping Issues

    - by Baddie
    Using VS 2010 beta 2, ASP.NET MVC. I tried to create an Entity framework file and got the data from my database. There were some issues with the relationships, so I started to tweak things around, but I kept getting the following error for simple one-to-one relationships Error 1 Error 113: Multiplicity is not valid in Role 'UserProfile' in relationship 'FK_UserProfiles_Users'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be *. myEntities.edmx 2024 My Users table is consists of some other many-to-many relationships to other tables, but when I try to make a one-to-one relationship with other tables, that error pops up. Users Table UserID Username Email etc.. UserProfiles Table UserProfileID UserID (FK for Users Table) Location Birthday

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  • 'Subquery returned more than 1 value' problem in EntityFramework

    - by plotnick
    I have one 'Transaction' entity object with 'Operations' navproperty with multiplicity of 'Many'. When I'm adding only one operation per transaction nothing happens, but when I'm trying to add more than one operation, db.SaveChanges() throws an exception like 'Subquery returned more than 1 value blah, blah, blah' How can I solve that? Help me guys please... BTW... Could you tell me how can I see the exact query string that EF passes to Sql Server on db.SaveChanges() method?

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  • Addicted to the MIX Buzz

    - by Dave Campbell
    Well it's the Friday before MIX10, and I'm officially of no use to anybody. I'll be driving up to 'Vegas Sunday ... hopefully rolling in mid-late afternoon, checking in at my $31.50/night (including WiFi) Motel, and getting registered then hanging out around registration to see who is there. First organized thing to do is 9PM, so I'm open to suggestions Sunday evening... maybe we can get a gang together for dinner ?? Monday is the Keynote ... I'm addicted to the buzz in the ballroom the first day, hope to be close to the front, trying to live blog. Then straight to Ballroom A and stake out the spot I'll be in for all 3 days, and you all know why :) I've tagged 40 sessions that I 'want' to see, and there's only 12 slots... damn... if I could, I'd try the Multiplicity thing, but I'm afraid I'd get the idiot first try -- or maybe got that one already :) ... but at least I tagged them to make it easy to find after the videos are up. Stuff going on Sunday, Monday, and Tuesday night. I'm staying over for an event on Thursday, and driving back on Friday. I'm not sure how much blogging I'll be doing, but I'll try to hit some 'Cream high spots. I'm sure everyone #NotAtMIX is going to be tuned into the sessions online. I'll be wearing TShirts with WynApse.com and SilverlightCream.com printed on the back... so if you see some old curmudgeon with such a shirt, IT'S ME! I look forward to seeing all the people I only see once or twice a year, and meeting ones I haven't met yet What a week... Bring It On and Stay in the 'Light! Technorati Tags: Silverlight    Silverlight 4    MIX10

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  • How do I delete a child entity from a parent collection with Entity Framework 4?

    - by simonjreid
    I'm using Entity Framework 4 and have a one-to-many relationship between a parent and child entity. I'm trying to delete a child using the parent repository by removing it from the parent's children collection: public virtual void RemoveChild(Child child) { children.Remove(child); } When I try to save the changes I get the following error: A relationship from the 'ParentChild' AssociationSet is in the 'Deleted' state. Given multiplicity constraints, a corresponding 'Child' must also in the 'Deleted' state. Surely I don't have to delete the child entity explicitly using a child repository!

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  • What is the "owning side" in an ORM mapping?

    - by Yousui
    Hi guys, I'm new to JPA. Now I have a question that what exactly is the owning side mean? I only have a rough idea of it. Can someone give me an explanation with some mapping examples(one to many, one to one, many to one) please? Great thanks. ps, the following text is excerpt from the decription of @OneToOne in java EE 6 documentation. You can see the concept owning side in it. Defines a single-valued association to another entity that has one-to-one multiplicity. It is not normally necessary to specify the associated target entity explicitly since it can usually be inferred from the type of the object being referenced. If the relationship is bidirectional, the non-owning side must use the mappedBy element of the OneToOne annotation to specify the relationship field or property of the owning side.

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  • Is it safe to reuse javax.xml.ws.Service objects

    - by Noel Ang
    I have JAX-WS style web service client that was auto-generated with the NetBeans IDE. The generated proxy factory (extends javax.xml.ws.Service) delegates proxy creation to the various Service.getPort methods. The application that I am maintaining instantiates the factory and obtains a proxy each time it calls the targetted service. Creating the new proxy factory instances repeatedly has been shown to be expensive, given that the WSDL documentation supplied to the factory constructor, an HTTP URI, is re-retrieved for each instantiation. We had success in improving the performance by caching the WSDL. But this has ugly maintenance and packaging implications for us. I would like to explore the suitability of caching the proxy factory itself. Is it safe, e.g., can two different client classes, executing on the same JVM and targetting the same web service, safely use the same factory to obtain distinct proxy objects (or a shared, reentrant one)? I've been unable to find guidance from either the JAX-WS specification nor the javax.xml.ws API documentation. The factory-proxy multiplicity is unclear to me. Having Service.getPort rather than Service.createPort does not inspire confidence.

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  • Using collections/containers/catalogs in Domain Models

    - by devoured elysium
    Let's say I want to model a cinema. The cinema will have a couple of rooms(for example, 7), where the movies are being played. I wonder how should I design the domain model for this scenario. Should the Cinema class concept concept have a direct association with the 7 rooms? Should the Cinema class concept have an association with a catalog of the 7 rooms? Why? I am having some trouble understanding why in some places I see the first case and in some others I see something like the second case. If instead of rooms, I wanted to depict the relationship between Cinema and: Tickets to sell (today). Tickets already sold (today) Customers in the Cinema database The set of hours at which there are movies playing in a given room in the cinema. The set of places you can sit at in a room in the cinema. Should I use catalogs, should I connect them directly to the Cinema concept with a multiplicity of * in the target? Thanks

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  • Conceptual data modeling: Is RDF the right tool? Other solutions?

    - by paprika
    I'm planning a system that combines various data sources and lets users do simple queries on these. A part of the system needs to act as an abstraction layer that knows all connected data sources: the user shouldn't [need to] know about the underlying data "providers". A data provider could be anything: a relational DBMS, a bug tracking system, ..., a weather station. They are hooked up to the query system through a common API that defines how to "offer" data. The type of queries a certain data provider understands is given by its "offer" (e.g. I know these entities, I can give you aggregates of type X for relationship Y, ...). My concern right now is the unification of the data: the various data providers need to agree on a common vocabulary (e.g. the name of the entity "customer" could vary across different systems). Thus, defining a high level representation of the entities and their relationships is required. So far I have the following requirements: I need to be able to define objects and their properties/attributes. Further, arbitrary relations between these objects need to be represented: a verb that defines the nature of the relation (e.g. "knows"), the multiplicity (e.g. 1:n) and the direction/navigability of the relation. It occurs to me that RDF is a viable option, but is it "the right tool" for this job? What other solutions/frameworks do exist for semantic data modeling that have a machine readable representation and why are they better suited for this task? I'm grateful for every opinion and pointer to helpful resources.

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  • Perl DBD::DB2 installation failed

    - by prabhu
    Hi, We dont have root access in our local machine. I installed DBI package first and then installed DBD package. I got the below error first, In file included from DB2.h:22, from DB2.xs:7: dbdimp.h:10:22: dbivport.h: No such file or directory Then I included the DBI path in the Makefile and then I am getting the below error. DB2.xs: In function `XS_DBD__DB2__db_disconnect': DB2.xs:128: error: structure has no member named `_old_cached_kids' DB2.xs:129: error: structure has no member named `_old_cached_kids' DB2.xs:130: error: structure has no member named `_old_cached_kids' DB2.xs: In function `XS_DBD__DB2__db_DESTROY': DB2.xs:192: error: structure has no member named `_old_cached_kids' DB2.xs:193: error: structure has no member named `_old_cached_kids' DB2.xs:194: error: structure has no member named `_old_cached_kids' The versions I am trying to install are DBI-1.610_90.tar.gz DBD-DB2-1.78.tar.gz I am using perl Makefile.PL PREFIX=/home/prabhu/perl_pm/lib The output for perl -V is as follows: Summary of my perl5 (revision 5 version 8 subversion 5) configuration: Platform: osname=linux, osvers=2.4.21-27.0.2.elsmp, archname=i386-linux-thread-multi uname='linux decompose.build.redhat.com 2.4.21-27.0.2.elsmp #1 smp wed jan 12 23:35:44 est 2005 i686 i686 i386 gnulinux ' config_args='-des -Doptimize=-O2 -g -pipe -m32 -march=i386 -mtune=pentium4 -Dversion=5.8.5 -Dmyhostname=localhost -Dperladmin=root@localhost -Dcc=gcc -Dcf_by=Red Hat, Inc. -Dinstallprefix=/usr -Dprefix=/usr -Darchname=i386-linux -Dvendorprefix=/usr -Dsiteprefix=/usr -Duseshrplib -Dusethreads -Duseithreads -Duselargefiles -Dd_dosuid -Dd_semctl_semun -Di_db -Ui_ndbm -Di_gdbm -Di_shadow -Di_syslog -Dman3ext=3pm -Duseperlio -Dinstallusrbinperl -Ubincompat5005 -Uversiononly -Dpager=/usr/bin/less -isr -Dinc_version_list=5.8.4 5.8.3 5.8.2 5.8.1 5.8.0' hint=recommended, useposix=true, d_sigaction=define usethreads=define use5005threads=undef useithreads=define usemultiplicity=define useperlio=define d_sfio=undef uselargefiles=define usesocks=undef use64bitint=undef use64bitall=undef uselongdouble=undef usemymalloc=n, bincompat5005=undef Compiler: cc='gcc', ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBUGGING -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/include/gdbm', optimize='-O2 -g -pipe -m32 -march=i386 -mtune=pentium4', cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBUGGING -fno-strict-aliasing -pipe -I/usr/local/include -I/usr/include/gdbm' ccversion='', gccversion='3.4.4 20050721 (Red Hat 3.4.4-2)', gccosandvers='' intsize=4, longsize=4, ptrsize=4, doublesize=8, byteorder=1234 d_longlong=define, longlongsize=8, d_longdbl=define, longdblsize=12 ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t', lseeksize=8 alignbytes=4, prototype=define Linker and Libraries: ld='gcc', ldflags =' -L/usr/local/lib' libpth=/usr/local/lib /lib /usr/lib libs=-lnsl -lgdbm -ldb -ldl -lm -lcrypt -lutil -lpthread -lc perllibs=-lnsl -ldl -lm -lcrypt -lutil -lpthread -lc libc=/lib/libc-2.3.4.so, so=so, useshrplib=true, libperl=libperl.so gnulibc_version='2.3.4' Dynamic Linking: dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E -Wl,-rpath,/usr/lib/perl5/5.8.5/i386-linux-thread-multi/CORE' cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib' Characteristics of this binary (from libperl): Compile-time options: DEBUGGING MULTIPLICITY USE_ITHREADS USE_LARGE_FILES PERL_IMPLICIT_CONTEXT Built under linux Compiled at Aug 2 2005 04:48:47 %ENV: PERL5LIB=":/opt/india/dev/perl/XML-XPath-1.13/lib/perl5:/opt/india/dev/perl/XML-XPath- 1.13/lib/perl5/site_perl:/opt/india/dev/perl/XML-XPath-1.13/lib/perl5:/opt/india/dev/perl/XML-XPath-1.13/lib/perl5/site_perl" Could anyone help me to resolve this issue? Appreciate help in advance. Prabhu

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  • How can I structure and recode messy categorical data in R?

    - by briandk
    I'm struggling with how to best structure categorical data that's messy, and comes from a dataset I'll need to clean. The Coding Scheme I'm analyzing data from a university science course exam. We're looking at patterns in student responses, and we developed a coding scheme to represent the kinds of things students are doing in their answers. A subset of the coding scheme is shown below. Note that within each major code (1, 2, 3) are nested non-unique sub-codes (a, b, ...). What the Raw Data Looks Like I've created an anonymized, raw subset of my actual data which you can view here. Part of my problem is that those who coded the data noticed that some students displayed multiple patterns. The coders' solution was to create enough columns (reason1, reason2, ...) to hold students with multiple patterns. That becomes important because the order (reason1, reason2) is arbitrary--two students (like student 41 and student 42 in my dataset) who correctly applied "dependency" should both register in an analysis, regardless of whether 3a appears in the reason column or the reason2 column. How Can I Best Structure Student Data? Part of my problem is that in the raw data, not all students display the same patterns, or the same number of them, in the same order. Some students may do just one thing, others may do several. So, an abstracted representation of example students might look like this: Note in the example above that student002 and student003 both are coded as "1b", although I've deliberately shown the order as different to reflect the reality of my data. My (Practical) Questions Should I concatenate reason1, reason2, ... into one column? How can I (re)code the reasons in R to reflect the multiplicity for some students? Thanks I realize this question is as much about good data conceptualization as it is about specific features of R, but I thought it would be appropriate to ask it here. If you feel it's inappropriate for me to ask the question, please let me know in the comments, and stackoverflow will automatically flood my inbox with sadface emoticons. If I haven't been specific enough, please let me know and I'll do my best to be clearer.

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  • Where'd My Data Go? (and/or...How Do I Get Rid of It?)

    - by David Paquette
    Want to get a better idea of how cascade deletes work in Entity Framework Code First scenarios? Want to see it in action? Stick with us as we quickly demystify what happens when you tell your data context to nuke a parent entity. This post is authored by Calgary .NET User Group Leader David Paquette with help from Microsoft MVP in Asp.Net James Chambers. We got to spend a great week back in March at Prairie Dev Con West, chalk full of sessions, presentations, workshops, conversations and, of course, questions.  One of the questions that came up during my session: "How does Entity Framework Code First deal with cascading deletes?". James and I had different thoughts on what the default was, if it was different from SQL server, if it was the same as EF proper and if there was a way to override whatever the default was.  So we built a set of examples and figured out that the answer is simple: it depends.  (Download Samples) Consider the example of a hockey league. You have several different entities in the league including games, teams that play the games and players that make up the teams. Each team also has a mascot.  If you delete a team, we need a couple of things to happen: The team, games and mascot will be deleted, and The players for that team will remain in the league (and therefore the database) but they should no longer be assigned to a team. So, let's make this start to come together with a look at the default behaviour in SQL when using an EDMX-driven project. The Reference – Understanding EF's Behaviour with an EDMX/DB First Approach First up let’s take a look at the DB first approach.  In the database, we defined 4 tables: Teams, Players, Mascots, and Games.  We also defined 4 foreign keys as follows: Players.Team_Id (NULL) –> Teams.Id Mascots.Id (NOT NULL) –> Teams.Id (ON DELETE CASCADE) Games.HomeTeam_Id (NOT NULL) –> Teams.Id Games.AwayTeam_Id (NOT NULL) –> Teams.Id Note that by specifying ON DELETE CASCADE for the Mascots –> Teams foreign key, the database will automatically delete the team’s mascot when the team is deleted.  While we want the same behaviour for the Games –> Teams foreign keys, it is not possible to accomplish this using ON DELETE CASCADE in SQL Server.  Specifying a ON DELETE CASCADE on these foreign keys would cause a circular reference error: The series of cascading referential actions triggered by a single DELETE or UPDATE must form a tree that contains no circular references. No table can appear more than one time in the list of all cascading referential actions that result from the DELETE or UPDATE – MSDN When we create an entity data model from the above database, we get the following:   In order to get the Games to be deleted when the Team is deleted, we need to specify End1 OnDelete action of Cascade for the HomeGames and AwayGames associations.   Now, we have an Entity Data Model that accomplishes what we set out to do.  One caveat here is that Entity Framework will only properly handle the cascading delete when the the players and games for the team have been loaded into memory.  For a more detailed look at Cascade Delete in EF Database First, take a look at this blog post by Alex James.   Building The Same Sample with EF Code First Next, we're going to build up the model with the code first approach.  EF Code First is defined on the Ado.Net team blog as such: Code First allows you to define your model using C# or VB.Net classes, optionally additional configuration can be performed using attributes on your classes and properties or by using a Fluent API. Your model can be used to generate a database schema or to map to an existing database. Entity Framework Code First follows some conventions to determine when to cascade delete on a relationship.  More details can be found on MSDN: If a foreign key on the dependent entity is not nullable, then Code First sets cascade delete on the relationship. If a foreign key on the dependent entity is nullable, Code First does not set cascade delete on the relationship, and when the principal is deleted the foreign key will be set to null. The multiplicity and cascade delete behavior detected by convention can be overridden by using the fluent API. For more information, see Configuring Relationships with Fluent API (Code First). Our DbContext consists of 4 DbSets: public DbSet<Team> Teams { get; set; } public DbSet<Player> Players { get; set; } public DbSet<Mascot> Mascots { get; set; } public DbSet<Game> Games { get; set; } When we set the Mascot –> Team relationship to required, Entity Framework will automatically delete the Mascot when the Team is deleted.  This can be done either using the [Required] data annotation attribute, or by overriding the OnModelCreating method of your DbContext and using the fluent API. Data Annotations: public class Mascot { public int Id { get; set; } public string Name { get; set; } [Required] public virtual Team Team { get; set; } } Fluent API: protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Mascot>().HasRequired(m => m.Team); } The Player –> Team relationship is automatically handled by the Code First conventions. When a Team is deleted, the Team property for all the players on that team will be set to null.  No additional configuration is required, however all the Player entities must be loaded into memory for the cascading to work properly. The Game –> Team relationship causes some grief in our Code First example.  If we try setting the HomeTeam and AwayTeam relationships to required, Entity Framework will attempt to set On Cascade Delete for the HomeTeam and AwayTeam foreign keys when creating the database tables.  As we saw in the database first example, this causes a circular reference error and throws the following SqlException: Introducing FOREIGN KEY constraint 'FK_Games_Teams_AwayTeam_Id' on table 'Games' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint. To solve this problem, we need to disable the default cascade delete behaviour using the fluent API: protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Mascot>().HasRequired(m => m.Team); modelBuilder.Entity<Team>() .HasMany(t => t.HomeGames) .WithRequired(g => g.HomeTeam) .WillCascadeOnDelete(false); modelBuilder.Entity<Team>() .HasMany(t => t.AwayGames) .WithRequired(g => g.AwayTeam) .WillCascadeOnDelete(false); base.OnModelCreating(modelBuilder); } Unfortunately, this means we need to manually manage the cascade delete behaviour.  When a Team is deleted, we need to manually delete all the home and away Games for that Team. foreach (Game awayGame in jets.AwayGames.ToArray()) { entities.Games.Remove(awayGame); } foreach (Game homeGame in homeGames) { entities.Games.Remove(homeGame); } entities.Teams.Remove(jets); entities.SaveChanges();   Overriding the Defaults – When and How To As you have seen, the default behaviour of Entity Framework Code First can be overridden using the fluent API.  This can be done by overriding the OnModelCreating method of your DbContext, or by creating separate model override files for each entity.  More information is available on MSDN.   Going Further These were simple examples but they helped us illustrate a couple of points. First of all, we were able to demonstrate the default behaviour of Entity Framework when dealing with cascading deletes, specifically how entity relationships affect the outcome. Secondly, we showed you how to modify the code and control the behaviour to get the outcome you're looking for. Finally, we showed you how easy it is to explore this kind of thing, and we're hoping that you get a chance to experiment even further. For example, did you know that: Entity Framework Code First also works seamlessly with SQL Azure (MSDN) Database creation defaults can be overridden using a variety of IDatabaseInitializers  (Understanding Database Initializers) You can use Code Based migrations to manage database upgrades as your model continues to evolve (MSDN) Next Steps There's no time like the present to start the learning, so here's what you need to do: Get up-to-date in Visual Studio 2010 (VS2010 | SP1) or Visual Studio 2012 (VS2012) Build yourself a project to try these concepts out (or download the sample project) Get into the community and ask questions! There are a ton of great resources out there and community members willing to help you out (like these two guys!). Good luck! About the Authors David Paquette works as a lead developer at P2 Energy Solutions in Calgary, Alberta where he builds commercial software products for the energy industry.  Outside of work, David enjoys outdoor camping, fishing, and skiing. David is also active in the software community giving presentations both locally and at conferences. David also serves as the President of Calgary .Net User Group. James Chambers crafts software awesomeness with an incredible team at LogiSense Corp, based in Cambridge, Ontario. A husband, father and humanitarian, he is currently residing in the province of Manitoba where he resists the urge to cheer for the Jets and maintains he allegiance to the Calgary Flames. When he's not active with the family, outdoors or volunteering, you can find James speaking at conferences and user groups across the country about web development and related technologies.

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  • Pain Comes Instantly

    - by user701213
    When I look back at recent blog entries – many of which are not all that current (more on where my available writing time is going later) – I am struck by how many of them focus on public policy or legislative issues instead of, say, the latest nefarious cyberattack or exploit (or everyone’s favorite new pastime: coining terms for the Coming Cyberpocalypse: “digital Pearl Harbor” is so 1941). Speaking of which, I personally hope evil hackers from Malefactoria will someday hack into my bathroom scale – which in a future time will be connected to the Internet because, gosh, wouldn’t it be great to have absolutely everything in your life Internet-enabled? – and recalibrate it so I’m 10 pounds thinner. The horror. In part, my focus on public policy is due to an admitted limitation of my skill set. I enjoy reading technical articles about exploits and cybersecurity trends, but writing a blog entry on those topics would take more research than I have time for and, quite honestly, doesn’t play to my strengths. The first rule of writing is “write what you know.” The bigger contributing factor to my recent paucity of blog entries is that more and more of my waking hours are spent engaging in “thrust and parry” activity involving emerging regulations of some sort or other. I’ve opined in earlier blogs about what constitutes good and reasonable public policy so nobody can accuse me of being reflexively anti-regulation. That said, you have so many cycles in the day, and most of us would rather spend it slaying actual dragons than participating in focus groups on whether dragons are really a problem, whether lassoing them (with organic, sustainable and recyclable lassos) is preferable to slaying them – after all, dragons are people, too - and whether we need lasso compliance auditors to make sure lassos are being used correctly and humanely. (A point that seems to evade many rule makers: slaying dragons actually accomplishes something, whereas talking about “approved dragon slaying procedures and requirements” wastes the time of those who are competent to dispatch actual dragons and who were doing so very well without the input of “dragon-slaying theorists.”) Unfortunately for so many of us who would just get on with doing our day jobs, cybersecurity is rapidly devolving into the “focus groups on dragon dispatching” realm, which actual dragons slayers have little choice but to participate in. The general trend in cybersecurity is that powers-that-be – which encompasses groups other than just legislators – are often increasingly concerned and therefore feel they need to Do Something About Cybersecurity. Many seem to believe that if only we had the right amount of regulation and oversight, there would be no data breaches: a breach simply must mean Someone Is At Fault and Needs Supervision. (Leaving aside the fact that we have lots of home invasions despite a) guard dogs b) liberal carry permits c) alarm systems d) etc.) Also note that many well-managed and security-aware organizations, like the US Department of Defense, still get hacked. More specifically, many powers-that-be feel they must direct industry in a multiplicity of ways, up to and including how we actually build and deploy information technology systems. The more prescriptive the requirement, the more regulators or overseers a) can be seen to be doing something b) feel as if they are doing something regardless of whether they are actually doing something useful or cost effective. Note: an unfortunate concomitant of Doing Something is that often the cure is worse than the ailment. That is, doing what overseers want creates unfortunate byproducts that they either didn’t foresee or worse, don’t care about. After all, the logic goes, we Did Something. Prescriptive practice in the IT industry is problematic for a number of reasons. For a start, prescriptive guidance is really only appropriate if: • It is cost effective• It is “current” (meaning, the guidance doesn’t require the use of the technical equivalent of buggy whips long after horse-drawn transportation has become passé)*• It is practical (that is, pragmatic, proven and effective in the real world, not theoretical and unproven)• It solves the right problem With the above in mind, heading up the list of “you must be joking” regulations are recent disturbing developments in the Payment Card Industry (PCI) world. I’d like to give PCI kahunas the benefit of the doubt about their intentions, except that efforts by Oracle among others to make them aware of “unfortunate side effects of your requirements” – which is as tactful I can be for reasons that I believe will become obvious below - have gone, to-date, unanswered and more importantly, unchanged. A little background on PCI before I get too wound up. In 2008, the Payment Card Industry (PCI) Security Standards Council (SSC) introduced the Payment Application Data Security Standard (PA-DSS). That standard requires vendors of payment applications to ensure that their products implement specific requirements and undergo security assessment procedures. In order to have an application listed as a Validated Payment Application (VPA) and available for use by merchants, software vendors are required to execute the PCI Payment Application Vendor Release Agreement (VRA). (Are you still with me through all the acronyms?) Beginning in August 2010, the VRA imposed new obligations on vendors that are extraordinary and extraordinarily bad, short-sighted and unworkable. Specifically, PCI requires vendors to disclose (dare we say “tell all?”) to PCI any known security vulnerabilities and associated security breaches involving VPAs. ASAP. Think about the impact of that. PCI is asking a vendor to disclose to them: • Specific details of security vulnerabilities • Including exploit information or technical details of the vulnerability • Whether or not there is any mitigation available (as in a patch) PCI, in turn, has the right to blab about any and all of the above – specifically, to distribute all the gory details of what is disclosed - to the PCI SSC, qualified security assessors (QSAs), and any affiliate or agent or adviser of those entities, who are in turn permitted to share it with their respective affiliates, agents, employees, contractors, merchants, processors, service providers and other business partners. This assorted crew can’t be more than, oh, hundreds of thousands of entities. Does anybody believe that several hundred thousand people can keep a secret? Or that several hundred thousand people are all equally trustworthy? Or that not one of the people getting all that information would blab vulnerability details to a bad guy, even by accident? Or be a bad guy who uses the information to break into systems? (Wait, was that the Easter Bunny that just hopped by? Bringing world peace, no doubt.) Sarcasm aside, common sense tells us that telling lots of people a secret is guaranteed to “unsecret” the secret. Notably, being provided details of a vulnerability (without a patch) is of little or no use to companies running the affected application. Few users have the technological sophistication to create a workaround, and even if they do, most workarounds break some other functionality in the application or surrounding environment. Also, given the differences among corporate implementations of any application, it is highly unlikely that a single workaround is going to work for all corporate users. So until a patch is developed by the vendor, users remain at risk of exploit: even more so if the details of vulnerability have been widely shared. Sharing that information widely before a patch is available therefore does not help users, and instead helps only those wanting to exploit known security bugs. There’s a shocker for you. Furthermore, we already know that insider information about security vulnerabilities inevitably leaks, which is why most vendors closely hold such information and limit dissemination until a patch is available (and frequently limit dissemination of technical details even with the release of a patch). That’s the industry norm, not that PCI seems to realize or acknowledge that. Why would anybody release a bunch of highly technical exploit information to a cast of thousands, whose only “vetting” is that they are members of a PCI consortium? Oracle has had personal experience with this problem, which is one reason why information on security vulnerabilities at Oracle is “need to know” (we use our own row level access control to limit access to security bugs in our bug database, and thus less than 1% of development has access to this information), and we don’t provide some customers with more information than others or with vulnerability information and/or patches earlier than others. Failure to remember “insider information always leaks” creates problems in the general case, and has created problems for us specifically. A number of years ago, one of the UK intelligence agencies had information about a non-public security vulnerability in an Oracle product that they circulated among other UK and Commonwealth defense and intelligence entities. Nobody, it should be pointed out, bothered to report the problem to Oracle, even though only Oracle could produce a patch. The vulnerability was finally reported to Oracle by (drum roll) a US-based commercial company, to whom the information had leaked. (Note: every time I tell this story, the MI-whatever agency that created the problem gets a bit shirty with us. I know they meant well and have improved their vulnerability handling/sharing processes but, dudes, next time you find an Oracle vulnerability, try reporting it to us first before blabbing to lots of people who can’t actually fix the problem. Thank you!) Getting back to PCI: clearly, these new disclosure obligations increase the risk of exploitation of a vulnerability in a VPA and thus, of misappropriation of payment card data and customer information that a VPA processes, stores or transmits. It stands to reason that VRA’s current requirement for the widespread distribution of security vulnerability exploit details -- at any time, but particularly before a vendor can issue a patch or a workaround -- is very poor public policy. It effectively publicizes information of great value to potential attackers while not providing compensating benefits - actually, any benefits - to payment card merchants or consumers. In fact, it magnifies the risk to payment card merchants and consumers. The risk is most prominent in the time before a patch has been released, since customers often have little option but to continue using an application or system despite the risks. However, the risk is not limited to the time before a patch is issued: customers often need days, or weeks, to apply patches to systems, based upon the complexity of the issue and dependence on surrounding programs. Rather than decreasing the available window of exploit, this requirement increases the available window of exploit, both as to time available to exploit a vulnerability and the ease with which it can be exploited. Also, why would hackers focus on finding new vulnerabilities to exploit if they can get “EZHack” handed to them in such a manner: a) a vulnerability b) in a payment application c) with exploit code: the “Hacking Trifecta!“ It’s fair to say that this is probably the exact opposite of what PCI – or any of us – would want. Established industry practice concerning vulnerability handling avoids the risks created by the VRA’s vulnerability disclosure requirements. Specifically, the norm is not to release information about a security bug until the associated patch (or a pretty darn good workaround) has been issued. Once a patch is available, the notice to the user community is a high-level communication discussing the product at issue, the level of risk associated with the vulnerability, and how to apply the patch. The notices do not include either the specific customers affected by the vulnerability or forensic reports with maps of the exploit (both of which are required by the current VRA). In this way, customers have the tools they need to prioritize patching and to help prevent an attack, and the information released does not increase the risk of exploit. Furthermore, many vendors already use industry standards for vulnerability description: Common Vulnerability Enumeration (CVE) and Common Vulnerability Scoring System (CVSS). CVE helps ensure that customers know which particular issues a patch addresses and CVSS helps customers determine how severe a vulnerability is on a relative scale. Industry already provides the tools customers need to know what the patch contains and how bad the problem is that the patch remediates. So, what’s a poor vendor to do? Oracle is reaching out to other vendors subject to PCI and attempting to enlist then in a broad effort to engage PCI in rethinking (that is, eradicating) these requirements. I would therefore urge all who care about this issue, but especially those in the vendor community whose applications are subject to PCI and who may not have know they were being asked to tell-all to PCI and put their customers at risk, to do one of the following: • Contact PCI with your concerns• Contact Oracle (we are looking for vendors to sign our statement of concern)• And make sure you tell your customers that you have to rat them out to PCI if there is a breach involving the payment application I like to be charitable and say “PCI meant well” but in as important a public policy issue as what you disclose about vulnerabilities, to whom and when, meaning well isn’t enough. We need to do well. PCI, as regards this particular issue, has not done well, and has compounded the error by thus far being nonresponsive to those of us who have labored mightily to try to explain why they might want to rethink telling the entire planet about security problems with no solutions. By Way of Explanation… Non-related to PCI whatsoever, and the explanation for why I have not been blogging a lot recently, I have been working on Other Writing Venues with my sister Diane (who has also worked in the tech sector, inflicting upgrades on unsuspecting and largely ungrateful end users). I am pleased to note that we have recently (self-)published the first in the Miss Information Technology Murder Mystery series, Outsourcing Murder. The genre might best be described as “chick lit meets geek scene.” Our sisterly nom de plume is Maddi Davidson and (shameless plug follows): you can order the paper version of the book on Amazon, or the Kindle or Nook versions on www.amazon.com or www.bn.com, respectively. From our book jacket: Emma Jones, a 20-something IT consultant, is working on an outsourcing project at Tahiti Tacos, a restaurant chain offering Polynexican cuisine: refried poi, anyone? Emma despises her boss Padmanabh, a brilliant but arrogant partner in GD Consulting. When Emma discovers His-Royal-Padness’s body (verdict: death by cricket bat), she becomes a suspect.With her overprotective family and her best friend Stacey providing endless support and advice, Emma stumbles her way through an investigation of Padmanabh’s murder, bolstered by fusion food feeding frenzies, endless cups of frou-frou coffee and serious surfing sessions. While Stacey knows a PI who owes her a favor, landlady Magda urges Emma to tart up her underwear drawer before the next cute cop with a search warrant arrives. Emma’s mother offers to fix her up with a PhD student at Berkeley and showers her with self-defense gizmos while her old lover Keoni beckons from Hawai’i. And everyone, even Shaun the barista, knows a good lawyer. Book 2, Denial of Service, is coming out this summer. * Given the rate of change in technology, today’s “thou shalts” are easily next year’s “buggy whip guidance.”

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