With Spring Data repositories, we are able to create queries to suit any situation. Earlier in this chapter, we saw findByName, which merely queries based on the domain object's name attribute.
The following table shows a more comprehensive collection of finders we can write with Spring Data MongoDB. To illustrate the breadth of these keywords, it presumes a domain model bigger than the Image class we defined earlier:
|
Finder Method |
Description |
|
findByLastName(...) |
Query based on lastName |
|
findByFirstNameAndLastName(...) |
Query based on firstName and lastName |
|
findByFirstNameAndManagerLastName(...) |
Query based on firstName and by a related manager's lastName |
|
findTop10ByFirstName(...) or findFirst10ByFirstName(...) |
Query based on firstName, but only return the first ten entries |
|
findByFirstNameIgnoreCase(...) |
Query by firstName, but ignore the case of the text |
|
findByFirstNameAndLastNameAllIgnoreCase(...) |
Query by firstName and lastName, but ignore the case of the text in ALL fields |
|
findByFirstNameOrderByLastNameAsc(...) |
Query by firstName, but order the results based on lastName in ascending order (or use Desc for descending order) |
|
findByBirthdateAfter(Date date) |
Query based on birthdate being after the date |
|
findByAgeGreaterThan(int age) |
Query based on age attribute being greater than age parameter. |
|
findByAgeGreaterThanEqual(int age) |
Query based on age attribute being greater than or equal to age parameter. |
|
findByBirthdateBefore(Date date) |
Query based on birthdate being before the date |
|
findByAgeLessThan(int age) |
Query based on age attribute being less than age parameter. |
|
findByAgeLessThanEqual(int age) |
Query based on age attribute being less than or equal to age parameter. |
|
findByAgeBetween(int from, int to) |
Query based on age being between from and to |
|
findByAgeIn(Collection ages) |
Query based on age being found in the supplied collection |
|
findByAgeNotIn(Collection ages) |
Query based on age NOT being found in the supplied collection |
|
findByFirstNameNotNull() or findByFirstNameIsNotNull() |
Query based on firstName not being null |
|
findByFirstNameNull() or findByFirstNameIsNull() |
Query based on firstName being null |
|
findByFirstNameLike(String f) or findByFirstNameStartingWith(String f) or findByFirstNameEndingWith(String f) |
Query based on input being a regular expression |
|
findByFirstNameNotLike(String f) or findByFirstNameIsNotLike(String f) |
Query based on input being a regex, with a MongoDB $not applied |
|
findByFirstnameContaining(String f) |
For a string input, query just like Like; for a collection, query testing membership in the collection |
|
findByFirstnameNotContaining(String f) |
For a string input, query like like NotLike; for a collection, query testing lack of membership in the collection |
|
findByFirstnameRegex(String pattern) |
Query using pattern as a regular expression |
|
findByLocationNear(Point p) |
Query by geospatial relation using MongoDB's $near |
|
findByLocationNear(Point p, Distance max) |
Query by geospatial relation using MongoDB's $near and $maxDistance |
|
findByLocationNear(Point p, Distance min, Distance max) |
Query by geospatial relation using MongoDB's $near, $minDistance, and $maxDistance |
|
findByLocationWithin(Circle c) |
Query by geospatial relation using MongoDB's $geoWithin, $circle, and distance |
|
findByLocationWithin(Box b) |
Query by geospatial relation using MongoDB's $geoWithin, $box, and square coordinates |
|
findByActiveIsTrue() |
Query by active being true |
|
findByActiveIsFalse() |
Query by active being false |
|
findByLocationExists(boolean e) |
Query by location having the same Boolean value as the input |
All of these aforementioned keywords can also be used to construct deleteBy methods.
While the previous table shows all the keywords supported for MongoDB repository queries, the following list shows the various supported return types:
- Image (or Java primitive types)
- Iterable<Image>
- Iterator<Image>
- Collection<Image>
- List<Image>
- Optional<Image> (Java 8 or Guava)
- Option<Image> (Scala or Vavr)
- Stream<Image>
- Future<Image>
- CompletableFuture<Image>
- ListenableFuture<Image>
- @Async Future<Image>
- @Async CompletableFuture<Image>
- @Async ListenableFuture<Image>
- Slice<Image>
- Page<Image>
- GeoResult<Image>
- GeoResults<Image>
- GeoPage<Image>
- Mono<Image>
- Flux<Image>
In a nutshell, just about every container type is covered by Spring Data, which means that we can pick the right solution to suit our needs. Since this book's focus is reactive programming, we'll stick with Mono and Flux, considering they encapsulate asynchronous + non-blocking + lazy, without impacting the client, and regardless of quantity.