criteria

问题 Suppose I have 2 JPA classes which model 2 entities in datastore (Google app engine) like these: @Entity public class Clazz { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Key classKey; @Basic private String classId; @Basic private String className; @ManyToOne private Subject subject; } @Entity public class Subject { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Key subjectKey; @Basic private String subjectId; @Basic private String subjectName; @OneToMany

问题 Suppose I have 2 JPA classes which model 2 entities in datastore (Google app engine) like these: @Entity public class Clazz { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Key classKey; @Basic private String classId; @Basic private String className; @ManyToOne private Subject subject; } @Entity public class Subject { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Key subjectKey; @Basic private String subjectId; @Basic private String subjectName; @OneToMany

问题 The args' type of method fetch() can be SingularAttribute, PluralAttribute, why not can't be ListAttribute ? Then, how to fetch a collection with critria api ? Thank you. 回答1: Of course it can, as Rasmus Franke said. Just check from the javadocs for FetchParent or try this: @Entity public class SomeEntity { @Id int id; @OneToMany List<OtherEntity> others; } @Entity public class OtherEntity { @Id int id; } CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<SomeEntity> cq = cb

问题 How to find row by column with null value? It doesn't work: $criteria->condition = '`seller_id` IS NULL'; 回答1: $criteria->addCondition('seller_id IS NULL'); $data= MODEL::model()->find($criteria); tried this? **seller_id** is the mapped column name in Yii , it may not be same as the actual column name in your database. 来源： https://stackoverflow.com/questions/5349788/yii-condition-is-null

问题 How to find row by column with null value? It doesn't work: $criteria->condition = '`seller_id` IS NULL'; 回答1: $criteria->addCondition('seller_id IS NULL'); $data= MODEL::model()->find($criteria); tried this? **seller_id** is the mapped column name in Yii , it may not be same as the actual column name in your database. 来源： https://stackoverflow.com/questions/5349788/yii-condition-is-null

问题 How to find row by column with null value? It doesn't work: $criteria->condition = '`seller_id` IS NULL'; 回答1: $criteria->addCondition('seller_id IS NULL'); $data= MODEL::model()->find($criteria); tried this? **seller_id** is the mapped column name in Yii , it may not be same as the actual column name in your database. 来源： https://stackoverflow.com/questions/5349788/yii-condition-is-null

问题 Hibernate provider does not generate prepared statement for non-string type parameters unless they are set to entityManager.createQuery(criteriaQuery).setParameter(Parameter p, T t); as done by EclipseLink, by default. What is the way to set such parameters, if they are supplied dynamically at run time. For example, CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder(); CriteriaQuery<Long>criteriaQuery=criteriaBuilder.createQuery(Long.class); Metamodel metamodel=entityManager

问题 Hibernate provider does not generate prepared statement for non-string type parameters unless they are set to entityManager.createQuery(criteriaQuery).setParameter(Parameter p, T t); as done by EclipseLink, by default. What is the way to set such parameters, if they are supplied dynamically at run time. For example, CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder(); CriteriaQuery<Long>criteriaQuery=criteriaBuilder.createQuery(Long.class); Metamodel metamodel=entityManager

问题 Lets say I have a table that holds information about festivals. Each festival has a start and end date. I want to select all the festivals that are live (that happen) on a given date. Meaning, I want to select all the festivals that their start date is before or on a given date, and that their end date is after or on a the same given date. So I went on to the repository class of the festival entity, and created a method to do just that. But the criteria argument "findBy" expects is an array,