diff --git a/src/main/antora/modules/ROOT/pages/repositories/core-concepts.adoc b/src/main/antora/modules/ROOT/pages/repositories/core-concepts.adoc index b326df769..7c56eb55e 100644 --- a/src/main/antora/modules/ROOT/pages/repositories/core-concepts.adoc +++ b/src/main/antora/modules/ROOT/pages/repositories/core-concepts.adoc @@ -37,6 +37,11 @@ public interface CrudRepository extends Repository { The methods declared in this interface are commonly referred to as CRUD methods. `ListCrudRepository` offers equivalent methods, but they return `List` where the `CrudRepository` methods return an `Iterable`. +[IMPORTANT] +==== +The repository interface implies a few reserved methods like `findById(ID identifier)` that always target the domain types identifier property regardless of its property name. Read more about this in "`xref:repositories/query-methods-details.adoc#repositories.query-methods.reserved-methods[Defining Query Methods]`". +==== + NOTE: We also provide persistence technology-specific abstractions, such as `JpaRepository` or `MongoRepository`. Those interfaces extend `CrudRepository` and expose the capabilities of the underlying persistence technology in addition to the rather generic persistence technology-agnostic interfaces such as `CrudRepository`. diff --git a/src/main/antora/modules/ROOT/pages/repositories/query-keywords-reference.adoc b/src/main/antora/modules/ROOT/pages/repositories/query-keywords-reference.adoc index 8b08388c5..7c47b8118 100644 --- a/src/main/antora/modules/ROOT/pages/repositories/query-keywords-reference.adoc +++ b/src/main/antora/modules/ROOT/pages/repositories/query-keywords-reference.adoc @@ -21,6 +21,20 @@ Consult the store-specific documentation for the exact list of supported keyword |`…Distinct…`| Use a distinct query to return only unique results. Consult the store-specific documentation whether that feature is supported. This keyword can occur in any place of the subject between `find` (and the other keywords) and `by`. |=============== +[[appendix.query.method.reserved]] +== Reserved methods + +The following table lists reserved methods that use predefined functionality which is directly invoked on the backing (store specific) implementation of the repository proxy. See also "`xref:repositories/query-methods-details.adoc#repositories.query-methods.reserved-methods[Defining Query Methods]`". + +.Reserved methods +|=============== +|`deleteAllById(Iterable identifiers)` +|`deleteById(ID identifier)` +|`existsById(ID identifier)` +|`findAllById(Iterable identifiers)` +|`findById(ID identifier)` +|=============== + [[appendix.query.method.predicate]] == Supported query method predicate keywords and modifiers diff --git a/src/main/antora/modules/ROOT/pages/repositories/query-methods-details.adoc b/src/main/antora/modules/ROOT/pages/repositories/query-methods-details.adoc index 40c9e9b53..73a0d7c3b 100644 --- a/src/main/antora/modules/ROOT/pages/repositories/query-methods-details.adoc +++ b/src/main/antora/modules/ROOT/pages/repositories/query-methods-details.adoc @@ -86,6 +86,37 @@ Whether ignoring cases is supported may vary by store, so consult the relevant s - You can apply static ordering by appending an `OrderBy` clause to the query method that references a property and by providing a sorting direction (`Asc` or `Desc`). To create a query method that supports dynamic sorting, see "`xref:repositories/query-methods-details.adoc#repositories.special-parameters[Paging, Iterating Large Results, Sorting & Limiting]`". +[[repositories.query-methods.reserved-methods]] +== Reserved Methods + +While repository methods typically bind to properties by name, there are a few exceptions to this rule when it comes to certain method names targeting the _identifier_ property. Those _reserved methods_ like `CrudRepository#findById` or just `findById` are targeting the _identifier_ property independent of the actual property name used in the declared method. + +Consider the following domain type holding a property `pk` marked as the identifier via `@Id` and a property called `id`. In this case you need to pay close attention to the naming of your lookup methods as they may collide with predefined signatures. + +==== +[source,java] +---- +public class User { + @Id + Long pk; <1> + Long id; <2> + // ... +} + +public interface UserRepository extends Repository { + Optional findById(Long id); <3> + Optional findByPk(Long pk); <4> + Optional findUserById(Long id); <5> +} +---- +<1> The identifier property / primary key. +<2> A property called id, but not the identifying one. +<3> Targets the `User#pk` property (the one marked with `@Id` which is considered to be the identifier) instead of `User#id` as the property name would suggest because it is one of the _reserved methods_. +<4> Targets the `User#pk` property by name. +<5> Targets the `User#id` property by using the descriptive token between `find` and `by` to avoid collisions with _reserved methods_. +==== + +This special behaviour not only targets lookup methods but also applies to the `exits` and `delete` ones. Please refer to the "`xref:repositories/query-keywords-reference.adoc#appendix.query.method.reserved[Repository query keywords]`" for the list of methods. + [[repositories.query-methods.query-property-expressions]] == Property Expressions