Hibernate 3 - Entity Associations and Relationships

Lazy Loading and Fetching Strategies lazy

• Understand the use of the lazy attribute
• Know the default behaviour, implications on operations made on detached objects.
• Given a mapping and Java Code, understand what SQL will be generated by hibernate

fetch

• Know the different values of the fetch attribute and their implications
• Know the default behaviour
• Given mapping and Java Code, understand what SQL will be generated by hibernate
• Understand precedence of fetch on lazy

outer-join

• Understand the meaning and historical use of outer-join

Collection Sorting and Ordering understand the difference between 'sort' and 'order-by' attributes
knows 'sort' attributes values and their meaning (unsorted, natural, Comparator class)
understand valid 'order-by' attribute values (SQL not HQL) Relationships types

Mapping and corresponding database structure for the following :

• Simple unidirectional mapping (many-to-one)
• Basic Collection mapping (one-to-many)
• Bi-directional Association
  • inverse meaning, inverse and indexed Collections (Map, List)
• Association mapping tables
  • mapping classic associations table with many-to-many relationships
  • Using component class to map association table containing association information
• one-to-one mapping
  • mapping table having as FK its PK.
  • mapping table having a separate column as FK

Also Cascading effect

• Know the values for the 'cascade' attribute and their effect.