one-to-many

问题 I'm using Spring(xml+annotations), Hibernate(annotations) in this web service project. The database relationship diagram, models, expected and actual output are given below, Database Table relationship Customer.java @Entity @Table(name="customer") public class Customer implements Serializable{ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="customer_id", unique=true, nullable =false) long customerId; @Column(name="name")

问题 I'm using Spring(xml+annotations), Hibernate(annotations) in this web service project. The database relationship diagram, models, expected and actual output are given below, Database Table relationship Customer.java @Entity @Table(name="customer") public class Customer implements Serializable{ private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy=GenerationType.IDENTITY) @Column(name="customer_id", unique=true, nullable =false) long customerId; @Column(name="name")

问题 I'm developing a RESTful web application -- Apigility driven and based on the Zend Framework 2. For the model layer I'm using the ZfcBase DbMapper. The model essentially consists of two entities: Project and Image ( 1:n ) and is currently implemented like this: ProjectCollection extends Paginator ProjectEntity ProjectMapper extends AbstractDbMapper ProjectService implements ServiceManagerAwareInterface ProjectServiceFactory implements FactoryInterface The same structure for Image . When the

问题 I need something similar to these 2 SO questions, but using Informix SQL syntax. Concatenate several fields into one with SQL SQL Help: Select statement Concatenate a One to Many relationship My data coming in looks like this: id codes 63592 PELL 58640 SUBL 58640 USBL 73571 PELL 73571 USBL 73571 SUBL I want to see it come back like this: id codes 63592 PELL 58640 SUBL, USBL 73571 PELL, USBL, SUBL See also group_concat() in Informix. 回答1: I believe that the answer you need is a user-defined

问题 In my Grails project I need to have a 1:N relationship between two domain classes. So, I've created the following domain class: class Receipt_HealthService { Receipt receipt HealthService healthService int quantity = 1 static constraints = { } } and in Receipt I have the following: @NotNull static hasMany = [healthServices:Receipt_HealthService] So a new table is created that has got the id of both domain class and the quantity field. When I call the save() method everything works well, but

问题 Similar to the question I asked here, if I wanted to list all of the foreign key relationships from a model, is there a way to detect these relationships (forward and backward) automatically? Specifically, if Model 1 reads class Mdl_one(models.Model): name = models.CharField(max_length=30) and Model 2 reads class Mdl_two(models.Model): mdl_one = models.ForeignKey(Mdl_one) name = models.CharField(max_length=30) Is there some meta command I can run from Mdl_one (like Model_one()._meta.one_to

问题 Similar to the question I asked here, if I wanted to list all of the foreign key relationships from a model, is there a way to detect these relationships (forward and backward) automatically? Specifically, if Model 1 reads class Mdl_one(models.Model): name = models.CharField(max_length=30) and Model 2 reads class Mdl_two(models.Model): mdl_one = models.ForeignKey(Mdl_one) name = models.CharField(max_length=30) Is there some meta command I can run from Mdl_one (like Model_one()._meta.one_to

问题 I have the following class diagram and I want to map it to a database (note that Person has a list with objects of class Vehicle). Also my database looks like: All tables in the database that represent a subclass of the Vehicle class have all the fields of the superclass Vehicle. Also, all the relations show a one-to-many relationship from Person to Vehicle, Car and Motorcycle. My hibernate mapping files are the following: Person.hbm.xml <hibernate-mapping package="...."> <class name="Person"

问题 I have the following class diagram and I want to map it to a database (note that Person has a list with objects of class Vehicle). Also my database looks like: All tables in the database that represent a subclass of the Vehicle class have all the fields of the superclass Vehicle. Also, all the relations show a one-to-many relationship from Person to Vehicle, Car and Motorcycle. My hibernate mapping files are the following: Person.hbm.xml <hibernate-mapping package="...."> <class name="Person"

问题 I have an existing data scheme I'm reluctant to change. There are two entities/tables: parent and child , with child having the foreign key column parent_id . It's a 1(parent)-to-n(children) relationship. Is it possible within Spring Data JDBC to have Child class reference Parent and not Parent have a Set<Child> property? Maybe both? (I know it is possible with hibernate, but I'd like to stay with JDBC). I.e. I want something like this: @Data public class Parent { @Id private Long id; } @Data