Detailed introduction about criteria API in hibernate

1. SQL-like punctuation and Non Extensible 

2. Social system rather than OO technique 

3. Issue in making seek inquiries on the fly 

4. Multifaceted nature increments with number of variable conditions 

5. Mistake inclined String link 

6. Coordinate utilization of question parameters in the inquiry string .

String query = "select o from Order as o join o.products as p where o.priceTotal > :priceTotalLower and o.priceTotal < :priceTotalUpper";           
Query q = sess.createQuery(query);
q.setDouble("priceTotalLower", Double.parseDouble(lower));
q.setDouble("priceTotalUpper",Double.parseDouble(upper));
List list = q.list()

List list = sess.createCriteria(Order.class)
.add(Restrictions.between(lower,upper).list();

1. Parts of the social approach 
2. Lessens the multifaceted nature
3. Multi-criteria look functionalities
4. Building Hibernate Queries on the fly 
5. Learning of SQL a bit much
6. Extensible since it utilizes OO approach
7. Interoperable since it has arrangement for including local SQL provisos too 
8. Rich arrangement of examination administrators
9. Business Objects as question parameters, without using essential and outside key references 
10. Upgrading inquiries by giving different JOIN Strategies
11. Gives cleaner, clearer, more dependable and more viable code.

1. Criteria

2. Criterion

3. Restrictions

4. Projection

5. Order

Criteria crit = session.createCriteria(Sale.class) ;
crit.addOrder( Order.desc("date") );
crit.addOrder( Order.asc("product.number") );

Simple Criteria Query:-

The accompanying code indicates how a straightforward Criteria inquiry is manufactured.

1 .It chooses the Insurance Object

2. Incorporates a Where provision protection name like '%a%'

3. Incorporates another Where proviso investmentAmount esteem in the vicinity of 1000 and 2500 comprehensive

4. Sets the quantity of most extreme outcomes as 5

session = sessionFactory.openSession();
Criteria crit = session.createCriteria(Insurance.class);
crit.add(Restrictions.like("insuranceName", "%a%")); 
crit.add(Expression.between("investAmount", new Integer(1000),new Integer(2500))); 
crit.setMaxResults(5); 
List insurances = crit.list();
for(Iterator it =insurances.iterator();it.hasNext();){
	Insurance insurance = (Insurance) it.next();
  System.out.println("ID: " + insurance.getLngInsuranceId());
  System.out.println("Name: " + insurance.getInsuranceName());
  System.out.println("Amount: " + insurance.getInvestAmount());
}

List sales = session.createCriteria(Sale.class)
    .add(Expression.ge("date",startDate)
    .add(Expression.le("date",endDate)
    .addOrder( Order.asc("date") )
    .setFirstResult(0)
    .setMaxResults(10)
    .list();

// Adds a WHERE Clause for comparing two columns,
session.createCriteria(Sale.class)
    .eqProperty("saleDate","releaseDate")
    .list();

// Adds a native SQL Restriction in the WHERE Clause
sess.createCriteria(Cat.class)
.add(Restrictions.sqlRestriction("lower({alias}.name) like lower(?)", "Fritz%",Hibernate.STRING) ) .list();

Disjunction disList = Restrictions.disjunction();
disList.add(Restrictions.eq("id",new Integer(1));
disList.add(Restrictions.eq("id",new Integer(2));
sess.createCriteria(Cat.class) .add(disList);
// This gives the WHERE Clause WHERE (id=1 OR id=2)

Conjunction conList = Restrictions.conjunction();
conList.add(Restrictions.eq("id",new Integer(1));
conList.add(Restrictions.eq("id",new Integer(2));
sess.createCriteria(Cat.class) .add(conList);
// This gives the WHERE Clause WHERE (id=1 AND id=2)

Conjunction conList = Restrictions.conjunction();
conList.add(Restrictions.disjunction() .add(Restrictions.eq("id",new Integer(1))));

// use LEFT JOIN FETCH for optimizing queries
from Sale sale where sale.date > :startDate left join fetch sale.product

session.createCriteria(Sale.class)
      .setFetchMode("product",FetchMode.EAGER)
      .setFetchMode("category",FetchMode.EAGER)
      .list();

// to find all the shirt models with sizes over 40.
// HQL: from Shirt shirt join shirt.availableSizes size where size.number > 40

Session.createCriteria(Shirt.class)
      .createCriteria("availableSizes")
      .add(Expression.gt("number", new Integer(40)))
      .list();

// Simple Projection
session.createCriteria(Cat.class)
      .add(Restrictions.gt("age", new Integer(10))
      .setProjection(Projections.rowCount())
      .list();

Criteria crit = session.createCriteria(Cat.class)
ProjectionList projList = Projections.projectionList();
projList.add(Projections.rowCount() );
projList.add(Projections.avg("weight") ) ;
projList.add(Projections.max("weight") ) ;
projList.add(Projections.groupProperty("color") ) ) ;
List result = crit.setProjection(projList).list();

Criteria crit = session.createCriteria(Employee.class);
crit.add(Restrictions.eq("zipCode", zipCode));
crit.add(Restrictions.gt("salary", new Integer(10000));
ProjectionList projList = Projections.projectionList();
projList.add(Projections.property("name"));
projList.add(Projections.property("age"));
projList.add(Projections.property("county"));
projList.add(Projections.property("job"));
crit.setProjection(projList);

// Initializing the text values to be used
Accommodation accommodationEx = new Accommodation();
accommodationEx.setCountry(country);
accommodationEx.setCapacity(capacity);

// Creating and fine tuning the example object
Example example = Example.create(accommodationEx)
    .ignoreCase() //Queries are case insensitive
    .excludeZeroes()  //zero-valued fields are ignored
    .excludeProperty("doNotUse") // this property is excluded
    .enableLike(MatchMode.ANYWHERE); //query string matching uses ‘%X%’

// Using the Example Object and adding further restrictions
List list = session.createCriteria(Accommodation.class)
    .add(example)
    .add(Expression.between("availabilityDate", startDate, endDate))
    .list();