Spring Data JPA Simple Query-interface method

First, the interface method to arrange the quick check

The following table organizes the accessible methods in a simple query, the Jparepository interface (which inherits the Crudrepository interface, the Pagingandsortingrepository interface). (1) First, according to the function of sorting, divided into save, delete, find a single, find multiple, the other 5 categories. (2) The method is not recommended to use gray, such methods are more Crudrepository interface, pagingandsortingrepository interface definition, and later Jparepository interface also defined alternative methods, more convenient to use, For example: When looking for multiple objects, it is easier to return a List than to return a iterable.

二、五个 Interface Detailed

1, Crudrepository interface.

where T is the entity class to manipulate, the ID is the type of the entity class primary key. This interface provides 11 common methods of operation.

@NoRepositoryBean public  interface crudrepository<t, ID extends serializable> extends repository<t, id > {     <s extends t> s save (s entity);//Save      <s extends t> iterable<s> Save (iterable<s> ent ities);//Bulk Save      T FindOne (ID ID);//Query an object by ID. Returns the object itself when the object does not exist, returns null       iterable<t> findAll ();//Queries all objects      iterable<t> findAll (iterable<id> IDS);//Query All objects based on the ID list      Boolean exists (ID ID);//Determine whether the object has     a long count () based on the ID, or the total number of computed objects      void Delete (ID ID);// Delete void Delete      (T entity) by ID;//delete an object     void Delete (iterable<? extends t> entities);//Bulk Delete, collection object (when the background is executed, One delete)    void DeleteAll ();//delete all (when performing in the background, one strip Delete)}

2, Pagingandsortingrepository interface.

This interface inherits the Crudrepository interface and provides two methods for paging and sorting functions.

@NoRepositoryBean public  Interface pagingandsortingrepository<t, ID extends serializable> extends Crudrepository<t, id> {  
    Iterable<t> findAll (sort sort);//Sort only      page<t> findAll (pageable pageable);//pagination and sorting  }  

3, Jparepository interface.

The interface inherits the Pagingandsortingrepository interface.

Also inherit the Querybyexampleexecutor interface, this is an "instance" to query the interface, follow-up and write the article detailed description.

 @NoRepositoryBeanpublic Interface jparepository<t, ID extends serializable> extends Pagingandsortingrepo Sitory<t, Id>, querybyexampleexecutor<t> {list<t> findAll ();//Query All objects, return List list<t> fi Ndall (sort sort); Query all objects and sort, return List list<t> findAll (iterable<id> IDs); Queries all objects based on the ID list, returning the list void flush (); Force the cache to synchronize with the database <s extends t> list<s> Save (iterable<s> entities); Bulk Save and return object list <s extends T> s Saveandflush (s entity); Save and Force synchronize database void Deleteinbatch (iterable<t> entities); Bulk Delete Collection objects (when background execution, generate a statement execution, with multiple or conditions) void deleteallinbatch ();//delete all (execute a statement, such as: Delete from user) T GetOne (ID ID); Queries an object by ID, returning a reference to the object (as distinguished from FindOne). When the object is not saved, the return reference is not NULL, but the individual property values are null @Override <s extends t> list<s> findAll (example<s> Example); Based on the instance query @Override <s extends t> list<s> findAll (example<s> Example, sort sort);//query by instance, and sort. }

A few notes:

(1) Several query, and batch save method, compared with Crudrepository interface, return is List, use more convenient.

(2) Added InBatch Delete, the actual execution, the background generates an SQL statement, more efficient. In comparison, the deletion method of the Crudrepository interface is a one-piece deletion, even if the deleteAll is a one-piece deletion.

(3) Add the GetOne () method, remember that the method returns an object reference, and when the queried object does not exist, its value is not NULL.

4. Jpaspecificationexecutor interface
This interface provides support for JPA criteria queries (dynamic queries). This interface is very useful , specific non-stick source.

5. Repository interface
This interface is the most basic interface, just a symbolic interface, there is no definition of any method, then what is the use of this interface? Since spring data JPA provides this interface, naturally it has its usefulness, for example, we do not want to provide some of the methods, such as we just want to provide additions and modifications, do not provide a Delete method, then the previous few interfaces are not done, this time, we can inherit this interface, Then copy the corresponding method inside the Crudrepository interface to the Repository interface.

Key words	Method naming	SQL WHERE clause
and	Findbynameandpwd	where Name=? and pwd =?
Or	Findbynameorsex	where Name=? or sex=?
Is,equals	Findbyid,findbyidequals	where id=?
Between	Findbyidbetween	where ID between? and?
LessThan	Findbyidlessthan	Where ID <?
Lessthanequals	Findbyidlessthanequals	Where ID <=?
GreaterThan	Findbyidgreaterthan	where ID >?
Greaterthanequal	Findbyagegreaterthanequal	Where is age >=?
After	Findbyidafter	where ID >?
Before	Findbyidbefore	Where ID <?
IsNull	Findbynameisnull	where name is null
Isnotnull,notnull	Findbynamenotnull	Where name is NOT NULL
Like	Findbynamelike	Where name like?
Notlike	Findbynamenotlike	Where name isn't like?
Startingwith	Findbynamestartingwith	Where name like '?% '
Endingwith	Findbynameendingwith	Where name like '%? '
Containing	Findbynamecontaining	Where name like '%?% '
By	Findbyidorderbyxdesc	where id=? ORDER BY x Desc
Not	Findbynamenot	where name <>?
Inch	Findbyidin (collection<?> c)	where ID in (?)
Notin	Findbyidnotin (collection<?> c)	where ID not in (?)
True	Findbyaaatue	where AAA = True
False	Findbyaaafalse	where AAA = False
IgnoreCase	Findbynameignorecase	where UPPER (name) =upper (?)
Top	findTop100	Top 10/where ROWNUM <=10

Example:

//Demo /**   comid                     State            effecttime         */ findtop1bycomidandstateandeffecttimebetweenorderbyeffecttim    Edesc,,,;  

Spring Data JPA Simple Query-interface method