Criteria Query Examples
In the last lesson we learnt how to use Criteria Query to select all the records from Insurance table. In this lesson we will learn how to restrict the results returned from the database. Different method provided by Criteria interface can be used with the help of Restrictions to restrict the records fetched from database.
Criteria Interface provides the following methods:
Method | Description |
add | The Add method adds a Criterion to constrain the results to be retrieved. |
addOrder | Add an Order to the result set. |
createAlias | Join an association, assigning an alias to the joined entity |
createCriteria | This method is used to create a new Criteria, "rooted" at the associated entity. |
setFetchSize | This method is used to set a fetch size for the underlying JDBC query. |
setFirstResult | This method is used to set the first result to be retrieved. |
setMaxResults | This method is used to set a limit upon the number of objects to be retrieved. |
uniqueResult |
This method is used to instruct the Hibernate to fetch and return the unique records from database. |
Class Restriction provides built-in criterion via static factory methods. Important methods of the Restriction class are:
Method | Description |
Restriction.allEq |
This is used to apply an "equals" constraint to each property in the key set of a Map |
Restriction.between |
This is used to apply a "between" constraint to the named property |
Restriction.eq |
This is used to apply an "equal" constraint to the named property |
Restriction.ge |
This is used to apply a "greater than or equal" constraint to the named property |
Restriction.gt |
This is used to apply a "greater than" constraint to the named property |
Restriction.idEq |
This is used to apply an "equal" constraint to the identifier property |
Restriction.ilike |
This is case-insensitive "like", similar to Postgres ilike operator |
Restriction.in |
This is used to apply an "in" constraint to the named property |
Restriction.isNotNull |
This is used to apply an "is not null" constraint to the named property |
Restriction.isNull |
This is used to apply an "is null" constraint to the named property |
Restriction.le |
This is used to apply a "less than or equal" constraint to the named property |
Restriction.like |
This is used to apply a "like" constraint to the named property |
Restriction.lt |
This is used to apply a "less than" constraint to the named property |
Restriction.ltProperty |
This is used to apply a "less than" constraint to two properties |
Restriction.ne |
This is used to apply a "not equal" constraint to the named property |
Restriction.neProperty |
This is used to apply a "not equal" constraint to two properties |
Restriction.not |
This returns the negation of an expression |
Restriction.or |
This returns the disjuction of two expressions |
Here is an example code that shows how to use
Restrictions.like method and restrict the maximum rows returned by query by
setting the Criteria.setMaxResults() value to 5.
package roseindia.tutorial.hibernate;
|