# JPA Repository 규칙

## Jpa Repository 기본 메소드

| Method and Description           | void | column                                                                           |
| -------------------------------- | ---- | -------------------------------------------------------------------------------- |
| deleteAllInBatch()               | void | Deletes all entites in a batch call.                                             |
| deleteInBatch(Iterable entities) | void | Deletes the given entities in a batch which means it will create a single Query. |
| findAll() List                   |      |                                                                                  |
| findAll(Sort sort)               | List |                                                                                  |
| flush()                          | void | Flushes all pending changes to the database.                                     |
| getOne(ID id)                    | T    | Returns a reference to the entity with the given identifier.                     |
| save(Iterable entities)          | List |                                                                                  |
| saveAndFlush(T entity)           | T    | Saves an entity and flushes changes instantly.                                   |

### Supported keywords inside method names

| 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)`                            |

## 참고

* <https://docs.spring.io/spring-data/jpa/docs/1.6.0.RELEASE/reference/html/jpa.repositories.html#jpa.query-methods>