Hibernate restrictions usage

ArticleDirectory

• Method description

Learning about criteria of Hibernate

 

Address: http://xuganggogo.javaeye.com/blog/440078

 

1. Method description

Method	Description
restrictions. EQ	=
restrictions. alleq	Use Map to impose multiple equal limits
restrictions. gt	>
restrictions. ge	=
restrictions. Lt
restrictions. Le	<=
restrictions. Between	between
restrictions. Like	like
restrictions. in	in
restrictions. And	and
restrictions. Or	or
Restrictions. sqlrestriction	Use SQL to limit queries

 

 

2. QBC common limits

Restrictions. EQ--> Equal, equal.

Restrictions. alleq--> The parameter is a map object, and multiple equal comparisons are performed using key/value, which is equivalent to multiple restrictions. EQ.

Restrictions. gt--> Great-than> greater

Restrictions. Ge--> Great-equal >=greater than or equal

Restrictions. lt--> Less-than, <less

Restrictions. Le--> Less-equal <= less than or equal

Restrictions.--> Between clause corresponding to SQL

Restrictions. Like--> Like clause corresponding to SQL

Restrictions. In--> Corresponding SQL in Clause

Restrictions. And--> And relationship

Restrictions. or--> Or relationship

Restrictions. isnull--> Determines whether the attribute is null. If it is null, true is returned.

Restrictions. isnotnull--> Opposite to isnull

Restrictions. sqlrestriction--> SQL-qualified Query

Order. ASC--> Sort by input fields in ascending order

Order. DESC--> Sort by input fields in descending order

Matchmode. Exact--> Exact string matching. equivalent to "like 'value '"

Matchmode. Anywhere--> The string matches in the middle. It is equivalent to "like '% value % '"

Matchmode. Start--> The position of the string at the beginning. It is equivalent to "like 'value % '"

Matchmode. End--> The position of the string at the end is equivalent to "like '% value '"

Example
Query all students aged between 20 and 30
List list = session. createcriteria (student. Class)
. Add (restrictions. Between ("Age", new INTEGER (20), new INTEGER (30). List ();
Query the student objects whose names are AAA, BBB, and CCC.
String [] names = {"AAA", "BBB", "CCC "};
List list = session. createcriteria (student. Class)
. Add (restrictions. In ("name", names). List ();
Query student objects with an empty age
List list = session. createcriteria (student. Class)
. Add (restrictions. isnull ("Age"). List ();
Query the students whose age is 20 or whose age is null
List list = session. createcriteria (student. Class)
. Add (restrictions. Or (restrictions. eq ("Age", new INTEGER (20 )),
Restrictions. isnull ("Age"). List ();

--------------------------------------------------------------------
Use QBC for dynamic query 
Public list findstudents (string name, int age ){

Criteria = session. createcriteria (student. Class );
If (name! = NULL ){
Criteria. Add (restrictions. liek ("name", name, matchmode. Anywhere ));
}
If (age! = 0 ){
Criteria. Add (restrictions. eq ("Age", new INTEGER (AGE )));
}
Criteria. addorder (order. ASC ("name"); // sort by name in ascending order
Return criteria. List ();
}

 

Bytes -----------------------------------------------------------------------------------

Today I used restrictions when writing hibernate advanced queries (of course expression can also be used). This class feels good.
The followingCodeWriting is not easy to read. In fact, the core is a sentence.
Restrictions. Or (restrictions. Like (), restrictions. Or (restrictions. Like ,........))
The or in it can be infinitely added. It is better to use it.

Session session = gethibernatetemplate (). getsessionfactory ()
. Opensession ();
Criteria = session. createcriteria (film. Class );
List <film> List = criteria. Add (
Restrictions. Or (restrictions. Like ("Description", key, matchmode. Anywhere ),
Restrictions. Or (restrictions. Like ("name", key, matchmode. Anywhere ),
Restrictions. Or (restrictions. Like ("direct", key, matchmode. Anywhere ),
Restrictions. Or (restrictions. Like ("mainplay", key, matchmode. Anywhere ),
Restrictions. Like ("filearea", key, matchmode. Anywhere). List ();

Session. Close ();
Return list;