查询创建器

与Spring-Data-JPA的查询创建器一致，如果你用过Spring-Data-JPA，那么对此应当熟悉。

示例

@Mapper
public interface StudentMapper extends BaseMapper<Student, Long> {

	@NamingQuery
	public List<Student> findByName(String name);
	@NamingQuery
	public int countByName(String name);
	@NamingQuery
	public List<Student> findByClasssName(String className);	
	@NamingQuery
	public List<Student> findTop5ByAddTimeAfter(Date addTimeBegin);
	@NamingQuery
	public List<Student> findByClasssNameOrderByClasssIdDescAddTimeAsc(String className);
}

在mapper中，使用@NamingQuery标识一个接口为查询创建器，否则会认为映射的的是由xml配置的statement
与Spring-Data-JPA一样，查询属性可以为关联实体的属性

@Mapper
public interface ClassMapper extends BaseMapper<Classs, Long> {

	@NamingQuery
	public List<Classs> findByTeacherListName(String teacherName);
	
	@NamingQuery
	public List<Classs> findByStudentListName(String studentName);
	
	@NamingQuery
	public List<Classs> findByStudentListNameInAndStudentListAgeGreaterThan(String[] studentNames, int age);

}

条件关键字

关键字	例子	JPQL 片段
And	findByLastnameAndFirstname	… where x.lastname = ?1 and x.firstname = ?2
Or	findByLastnameOrFirstname	… where x.lastname = ?1 or x.firstname = ?2
Between	findByStartDateBetween	… where x.startDate between 1? and ?2
LessThan	findByAgeLessThan	… where x.age < ?1
GreaterThan	findByAgeGreaterThan	… where x.age > ?1
After	findByStartDateAfter	… where x.startDate > ?1
Before	findByStartDateBefore	… where x.startDate < ?1
IsNull	findByAgeIsNull	… where x.age is null
IsNotNull,NotNull	findByAge(Is)NotNull	… where x.age not null
Like	findByFirstnameLike	… where x.firstname like ?1
NotLike	findByFirstnameNotLike	… where x.firstname not like ?1
StartingWith	findByFirstnameStartingWith	… where x.firstname like ?1(parameter bound with appended %)
EndingWith	findByFirstnameEndingWith	… where x.firstname like ?1(parameter bound with prepended %)
Containing	findByFirstnameContaining	… where x.firstname like ?1(parameter bound wrapped in %)
OrderBy	findByAgeOrderByLastnameDesc	… where x.age = ?1 order by x.lastname desc
Not	findByLastnameNot	… where x.lastname <> ?1
In	findByAgeIn(Collection ages)	… where x.age in ?1
NotIn	findByAgeNotIn(Collection age)	… where x.age not in ?1
True	findByActiveTrue()	… where x.active = true
False	findByActiveFalse()	… where x.active = false

操作关键字

关键字	例子	JPQL 片段
find/read/get/query/stream	findByLastname	select ... where x.lastname = ?1
count	countByLastname	select count(*) from ... where x.lastname = ?1
Distinct	findDistinctByLastname	select distinct ... where x.lastname = ?1
delete/remove	deleteByLastname	delete from ... where x.lastname = ?1

行限制关键字(示例目标数据库为Mysql)

关键字	例子	JPQL 片段
Top	findTop5ByLastname	select ... where x.lastname = ?1 limit 5
First	findFirstByLastname	select ... where x.lastname = ?1 limit 1