composite-key

问题 I have a class that I want to use for a document key in RavenDB: public class DocumentKey { public string Namespace { get; set; } public string Id { get; set; } } I've also implemented the ITypeConverter (not the .NET one, the RavenDB-specific one) interface to convert from the reference type to a string (because in the database, the keys are all really just strings). Finally, I've added the implementation of ITypeConverter to the IDocumentStore implementation through the List<ITypeConverter>

问题 I have simple hibernate mapping <class name="com.domain.OtherAccount" table="ACCOUNT"> <composite-id > <key-property name="acctype" column="acctype" type="java.lang.Character"></key-property> <key-property name="accnum" column="accnum" type="java.lang.Integer"></key-property> </composite-id> <property name="accholder"></property> </class> I do not want to create separate class for Composite Key. So, acctype and accnum are part of OtherAccount class only. Class implements serializable

问题 I'm on my research for storing logs to Cassandra. The schema for logs would be something like this. EDIT: I've changed the schema in order to make some clarification. CREATE TABLE log_date ( userid bigint, time timeuuid, reason text, item text, price int, count int, PRIMARY KEY ((userid), time) - #1 PRIMARY KEY ((userid), time, reason, item, price, count) - #2 ); A new table will be created for the day everyday. So a table contains logs for only one day. My querying condition is as follows.

问题 I can successfully create composite primary key in sql server management studio 2012 by selecting two columns (OrderId, CompanyId) and right click and set as primary key. But i don't know how to create foreign key on two columns(OrderId, CompanyId) in other table by using sql server management studio 2012. 回答1: In Object Explorer, go to your table and select Keys > New Foreign Key from the context menu: From the dialog box that pops up, click on the Add button to create a new foreign key:

问题 where can I find samples for this? Most of my code using ColumnFamilyTemplate to do CRUD on the data records, see below. Once I have the composite key defined, can I still use ColumnFamilyTemplate to access my data having composite keys? private static final ColumnFamilyTemplate<UUID, String> template = new ThriftColumnFamilyTemplate<UUID, String>( Bootstrap.keyspace, "User", UUIDSerializer.get(), StringSerializer.get(), HFactory.createMutator(Bootstrap.keyspace, UUIDSerializer.get())); 回答1:

问题 I have a question about how design a resource URI with composite keys. I have a resource called freight that has 4 keys/ids: partner ID, initial zipcode, final zipcode and weight. Actually my resource was designed to have an incremental ID generated by database, but this approach is not so good to API consumers, for example if a consumer/partner needs to update a freight info they have to do: GET freight?initialZipcode={VALUE}&finalZipcode={VALUE}&weight={VALUE} The response of the operation

问题 The re-design for a large database at our company makes extensive use of composite primary keys on the database. Forgetting performance impacts, will this cause any difficulties when working with this db in Entity Framework 4.0? The database structure is unlikely to change and I'm not looking for "philosophical" debate but what are the practical impacts? According to Jeremy Miller, "Composite key make any kind of Object/Relational mapping and persistance in general harder." but he doesn't

问题 I am using DB2 DBMS. Scenario 1: myTable has a composite key (key1, key2) where both key1 and key2 are foreign keys from yourTable. I want to insert new data from yourTable into myTable, but only if the key1, key2 combination does not already exist in myTable. insert into myTable(key1, key2, someData) values(x, y, z) where NOT EXISTS (want to check if composite key is not already present) Scenario 2: I put data into a java object from yourTable with properties data1, data2, and data. I want

问题 We have a fairly big DB (~200 tables) which almost entirely uses composite primary keys and composite foreign keys, using a single "base table" from which every other table inherits part of its primary key: Parent has single column primary key ParentId Child has composite primary key (ParentId, ChildId) and foreign key ParentId Nephew has composite primary key (ParentId, NephewId), foreign key ParentId and foreign key (ParentId, ChildId) and so on. Up until now we managed this whole shebang

问题 I am designing a database using Entity Framework's "model-first" approach. Based on excellent feedback I recieved here, I am adopting a super-type/sub-type pattern for part of the DB. This pattern requires composite keys based on 2 columns in at least 2 tables (see schema below). I've searched the forum for "entity framework" and "composite keys", but none of the questions I found were on this more basic level: Can I set up an entity model so that it will generate one table (using "Generate