Go to: Hibernate query method

1: QBE (query by example)

Criteria CRI = session. createcriteria (student. Class); CRI. Add (example. Create (s); // s is a student object listcri. List ();

Essence: Create a template. For example, I have a table serial with a giftortoy field. I set serial. setgifttoy ("2 "),

All the giftortoy Data in this table is returned.

　　2: QBC (query bycriteria) mainly consists of criteria, criterion, Oder, restrictions class

　
Session = This. getsession (); Criteria
CRI = session. createcriteria (jditemserialnumber. Class); Criterion
Cron = restrictions. Like ("customer", name); CRI. Add (cron); List = CRI. List ();

Comparison Operators

Hql operator QBC operator meaning

= Restrictions. eq () equals

<> Restrictions. Not (exprission. eq () is not equal

> Restrictions. gt () is greater

> = Restrictions. Ge () is greater than or equal

<= Restrictions. Le () is less than or equal

Is null restrictions. isnull () is null

Is not nullrestrictions. isnotnull () non-null

Like restrictions. Like () string mode matching

And restrictions. And () logic and

And restrictions. conjunction () logic and

Or restrictions. Or () logic or

Or restrictions. disjunction () logic or

Notrestrictions. Not () logical non-

In (list) restrictions. In () is equal to a value in the list.

ONT in (list) restrictions. Not (restrictions. In () is not equal to any value in the list

Any value in between x and yrestrictions. Between () closed range XY

Not between x and yrestrictions. Not (restrictions... between () is smaller than the value x or greater than the value Y

　　3: hql

　
String hql = "select S. Name, AVG (S. Age) from student s
Groupbys. Name "; query =
Session. createquery (hql); List = query. List ();....

　　4: Local SQL query

　　5: qid

The get () and load () Methods of the session provide the way to retrieve Objects Based on the Object ID. This method is used to know the ID of the object to be retrieved in advance.

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