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Include Entity-state detection documentation snipped from Commons.

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Closes #579
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Mark Paluch
2021-04-13 15:20:39 +02:00
parent 5397152ae9
commit 635f30a865
1 changed files with 1 additions and 16 deletions
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src/main/asciidoc/reference/r2dbc-repositories.adoc
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@@ -321,22 +321,7 @@ Query By Example really shines when you you don't know all the fields needed in
If you were building a filter on a web page where the user can pick the fields, Query By Example is a great way to flexibly capture that into an efficient query.
[[r2dbc.entity-persistence.state-detection-strategies]]
=== Entity State Detection Strategies
The following table describes the strategies that Spring Data R2DBC offers for detecting whether an entity is new:
.Options for detection whether an entity is new in Spring Data R2DBC
[options = "autowidth"]
|===============
|Id-Property inspection (the default) |By default, the `save()` method inspects the identifier property of the given entity.
If the identifier property is `null`, then the entity is assumed to be new. Otherwise, it is assumed exist in the datbase.
|Implementing `Persistable` |If an entity implements `Persistable`, Spring Data R2DBC delegates the new detection to the `isNew(…)` method of the entity.
See the link:$$https://docs.spring.io/spring-data/data-commons/docs/current/api/index.html?org/springframework/data/domain/Persistable.html$$[Javadoc] for details.
|Optimistic Locking through `@Version` | If an entity uses Optimistic Locking by (version property annotated with `@Version`), Spring Data R2DBC checks if the entity is new by inspecting the version property whether its value corresponds with Java's default initialization value. That is `0` for primitive types and `null` for wrapper types.
|Implementing `EntityInformation` |You can customize the `EntityInformation` abstraction used in `SimpleR2dbcRepository` by creating a subclass of `R2dbcRepositoryFactory` and overriding `getEntityInformation(…)`.
You then have to register the custom implementation of `R2dbcRepositoryFactory` as a Spring bean.
Note that this should rarely be necessary. See the link:{spring-data-r2dbc-javadoc}/org/springframework/data/r2dbc/repository/support/R2dbcRepositoryFactory.html[Javadoc] for details.
|===============
include::../{spring-data-commons-docs}/is-new-state-detection.adoc[leveloffset=+2]
[[r2dbc.entity-persistence.id-generation]]
=== ID Generation