Spring Data JPA 关键字Exists
查询数据库中的此数据是否已存在：
例子：
查询sys_user表中的一个user是否存在，类SysUser对应的是数据库中的sys_user表，SysUserId是表sys_user的主键类（ID类）。
如果查询一个user，user的accountNo为demo。
userID为demo1，表sys_user的主键是accountNo和userID，下面代码中的方法是查询这个user是否存在，如果存在则返回true，不存在则返回false。
@Repository
public interface SysUserRepository extends JpaRepository<SysUser, SysUserId> {
@Override
boolean exists(SysUserId sysUserId);
}
Spring data jpa支持的关键字介绍
| Sample | JPQL snippet | |
|---|---|---|
|
And |
findByLastnameAndFirstname |
… where x.lastname = ?1 and x.firstname = ?2 |
|
Or |
findByLastnameOrFirstname |
… where x.lastname = ?1 or x.firstname = ?2 |
|
Is,Equals |
findByFirstname,findByFirstnameIs,findByFirstnameEquals |
… where x.firstname = ?1 |
|
Between |
findByStartDateBetween |
… where x.startDate between ?1 and ?2 |
|
LessThan |
findByAgeLessThan |
… where x.age < ?1 |
|
LessThanEqual |
findByAgeLessThanEqual |
… where x.age <= ?1 |
|
GreaterThan |
findByAgeGreaterThan |
… where x.age > ?1 |
|
GreaterThanEqual |
findByAgeGreaterThanEqual |
… 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<Age> ages) |
… where x.age in ?1 |
|
NotIn |
findByAgeNotIn(Collection<Age> age) |
… where x.age not in ?1 |
|
True |
findByActiveTrue() |
… where x.active = true |
|
False |
findByActiveFalse() |
… where x.active = false |
|
IgnoreCase |
findByFirstnameIgnoreCase |
… where UPPER(x.firstame) = UPPER(?1) |
| Keyword | Sample | JPQL snippet |
|---|---|---|
|
And |
findByLastnameAndFirstname |
… where x.lastname = ?1 and x.firstname = ?2 |
|
Or |
findByLastnameOrFirstname |
… where x.lastname = ?1 or x.firstname = ?2 |
|
Is,Equals |
findByFirstname,findByFirstnameIs,findByFirstnameEquals |
… where x.firstname = ?1 |
|
Between |
findByStartDateBetween |
… where x.startDate between ?1 and ?2 |
|
LessThan |
findByAgeLessThan |
… where x.age < ?1 |
|
LessThanEqual |
findByAgeLessThanEqual |
… where x.age <= ?1 |
|
GreaterThan |
findByAgeGreaterThan |
… where x.age > ?1 |
|
GreaterThanEqual |
findByAgeGreaterThanEqual |
… 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<Age> ages) |
… where x.age in ?1 |
|
NotIn |
findByAgeNotIn(Collection<Age> age) |
… where x.age not in ?1 |
|
True |
findByActiveTrue() |
… where x.active = true |
|
False |
findByActiveFalse() |
… where x.active = false |
|
IgnoreCase |
findByFirstnameIgnoreCase |
… where UPPER(x.firstame) = UPPER(?1) |
以上为个人经验，希望能给大家一个参考，也希望大家多多支持猪先飞。