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, a full iteration over the Cartesian product is avoided. [INNER] JOIN As discussed above, range ... an additional type of identification variable, a join variable, which represent a more limited iteration over specified collections of objects. The following query uses one range variable and one join

JPA Interface Join Type Parameters: - the source type of the join - the target type of the join A join to an entity, embeddable, or basic type. Since: JPA 2.0 The FROM clause (JPQL / Criteria API) article explains how to use Join . Public Methods Attribute getAttribute () Return the metamodel

the equivalent JOIN query. Entity Type Expressions The TYPE operator (which is new in JPA 2) returns the type ... its subinterfaces ( From , Root , Join and Join 's descendants). Path Expressions The Root and Join interfaces ... Variable Paths: Root country = query. from (Country.class); Join neighborCountry = country. join

( composite ) indices. Collection and array elements are indexable (extremely fast JOIN queries ... optimizations. Configurable JPA eager/lazy fetch  and JPA query FETCH JOIN . Configurable JDO fetch ... , max) - for paging. Query Structure SELECT (including NEW ). FROM (including INNER JOIN , LEFT OUTER

JPA Method in javax.persistence.criteria.From Join join (    SingularAttribute  attribute,     JoinType  jt ) Create a join to the specified single-valued attribute using the given join type. Parameters: attribute - target of the join jt - join type Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.CriteriaBuilder Join treat (    Join   join ,    Class  type ) Downcast Join object to the specified type. Parameters: join - Join object type - type to be downcast to Return: Join object of the specified type Since: JPA 2.1

JPA Method in javax.persistence.criteria.From Join join (   String attributeName,     JoinType  jt ) Create a join to the specified attribute using the given join type. Parameters: attributeName - name of the attribute for the target of the join jt - join type

JPA Method in javax.persistence.criteria.From MapJoin join (    MapAttribute  map,     JoinType  jt ) Create a join to the specified Map-valued attribute using the given join type. Parameters: map - target of the join jt - join type Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From SetJoin join (    SetAttribute  set,     JoinType  jt ) Create a join to the specified Set-valued attribute using the given join type. Parameters: set - target of the join jt - join type Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From ListJoin join (    ListAttribute  list,     JoinType  jt ) Create a join to the specified List-valued attribute using the given join type. Parameters: list - target of the join jt - join type Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From CollectionJoin join (    CollectionAttribute  collection,     JoinType  jt ) Create a join to the specified Collection-valued attribute using the given join type. Parameters: collection - target of the join jt - join type Return: the resulting join Since: JPA 2.0

variables (bound by an entity class) are represented by the Root subinterface: Join variables (bound by an attribute of a preceding variable in the FROM clause) are represented by the Join subinterface ... and examples. Join Fetch Elements Join Fetch is managed in criteria queries by the following interfaces

JPA Method in javax.persistence.criteria.From Join join (    SingularAttribute  attribute ) Create an inner join to the specified single-valued attribute. Parameters: attribute - target of the join Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria. Join Join on (   Predicate... restrictions ) Modify the join to restrict the result according to the specified ON condition and return the join object. Replaces the previous ON condition, if any. Parameters: restrictions - zero or

JPA Method in javax.persistence.criteria. Join Join on (    Expression  restriction ) Modify the join to restrict the result according to the specified ON condition and return the join ... boolean expression Return: the modified join object Since: JPA 2.1

JPA Method in javax.persistence.criteria.From Join join (   String attributeName ) Create an inner join to the specified attribute. Parameters: attributeName - name of the attribute for the target of the join Return: the resulting join Throws: IllegalArgumentException - if attribute of the given name does not exist Since: JPA 2.0

JPA Method in javax.persistence.criteria.From SetJoin join (    SetAttribute  set ) Create an inner join to the specified Set-valued attribute. Parameters: set - target of the join Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From CollectionJoin join (    CollectionAttribute  collection ) Create an inner join to the specified Collection-valued attribute. Parameters: collection - target of the join Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From ListJoin join (    ListAttribute  list ) Create an inner join to the specified List-valued attribute. Parameters: list - target of the join Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria.From MapJoin join (    MapAttribute  map ) Create an inner join to the specified Map-valued attribute. Parameters: map - target of the join Return: the resulting join Since: JPA 2.0

JPA Method in javax.persistence.criteria. Join Attribute getAttribute () Return the metamodel attribute corresponding to the join . Return: metamodel attribute corresponding to the join Since: JPA 2.0

JPA Method in javax.persistence.criteria. Join From getParent () Return the parent of the join . Return: join parent Since: JPA 2.0

JPA Method in javax.persistence.criteria. Join JoinType getJoinType () Return the join type. Return: join type Since: JPA 2.0

JPA Method in javax.persistence.criteria.CriteriaBuilder MapJoin treat (    MapJoin   join ,    Class  type ) Downcast MapJoin object to the specified type. Parameters: join - MapJoin object type - type to be downcast to Return: MapJoin object of the specified type Since: JPA 2.1

JPA Method in javax.persistence.criteria.CriteriaBuilder ListJoin treat (    ListJoin   join ,    Class  type ) Downcast ListJoin object to the specified type. Parameters: join - ListJoin object type - type to be downcast to Return: ListJoin object of the specified type Since: JPA 2.1

JPA Method in javax.persistence.criteria. Join Predicate getOn () Return the predicate that corresponds to the ON restriction(s) on the join , or null if no ON condition has been specified. Return: the ON restriction predicate Since: JPA 2.1

JPA Method in javax.persistence.criteria.CriteriaBuilder SetJoin treat (    SetJoin   join ,    Class  type ) Downcast SetJoin object to the specified type. Parameters: join - SetJoin object type - type to be downcast to Return: SetJoin object of the specified type Since: JPA 2.1

JPA Method in javax.persistence.criteria.CriteriaBuilder CollectionJoin treat (    CollectionJoin   join ,    Class  type ) Downcast CollectionJoin object to the specified type. Parameters: join - CollectionJoin object type - type to be downcast to Return: CollectionJoin object of the specified type Since: JPA 2.1

JPA Enum Constant in javax.persistence.InheritanceType JOINED A strategy in which fields that are specific to a subclass are mapped to a separate table than the fields that are common to the parent class, and a join is performed to instantiate the subclass. Since: JPA 1.0

to an entity in the from clause. Serves as a factory for Joins of associations, embeddables, and collections ... Methods Fetch fetch ( PluralAttribute  attribute) Create a fetch join to the specified collection-valued attribute using an inner join . Parameters: attribute - target of the join Return: the resulting

in the results directly, but their content can be added to the SELECT clause by using a bound JOIN

, multiselect , array , tuple , construct ). Criteria FROM  ( from , join , fetch ). Criteria WHERE  

elements (representing range variables, join and fetch): Other criteria query expressions (for all the query clauses):

JDO Annotation Join Target: ElementType.TYPE, ElementType.FIELD, ElementType.METHOD Implemented Interfaces: Annotation Annotation for the join of a relation. Corresponds to the xml element " join ". Since: JDO 2.1 Public Annotation Attributes String column default "" Name of the column in the join

JDO Annotation Joins Target: ElementType.TYPE Implemented Interfaces: Annotation Annotation for a group of joins . Since: JDO 2.1 Public Annotation Attributes Join [] value default null The join definitions used for the mapping of this type. Joins for secondary tables are usually defined

JDO Annotation Attribute in javax.jdo.annotations. Joins Join [] value default null The join definitions used for the mapping of this type. Joins for secondary tables are usually defined at the type ... the same join definition and avoid redundancies. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join Column [] columns default {} Detail definition of the join column(s). This is needed for more than one join column. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String table default "" Table to join to (used when joining to secondary tables). Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String generateForeignKey default "" Generate or assume a foreign key constraint exists on the column or columns associated with this join . Specify "true" or "false". Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join ForeignKeyAction deleteAction default ForeignKeyAction.UNSPECIFIED Delete action to be applied to any ForeignKey on this join . Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String outer default "" Whether to use an outer join . Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String generatePrimaryKey default "" Generate or assume a primary key constraint exists on the column or columns associated with this join . Specify "true" or "false". Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String unique default "" Whether the join column is unique. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String indexed default "" Whether the join column is indexed. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String column default "" Name of the column in the join table. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String primaryKey default "" Name for a generated primary key constraint. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join Extension [] extensions default {} Vendor extensions. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String foreignKey default "" Name for a generated foreign key constraint. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String uniqueKey default "" The name of the unique key constraint to generate. Since: JDO 2.1

JDO Annotation Attribute in javax.jdo.annotations. Join String index default "" The name of the index to generate. Since: JDO 2.1