我对以下代码有疑问，它只返回每个表的第一个结果。
@Service
@Slf4j
@Lazy
@AllArgsConstructor
public class QuizQueryService {
R2dbcEntityOperations client;
@Transactional(readOnly = true)
public Flux<QuizWithoutResults> getAllQuizzes(String courseId) {
return getAllQuizEntitiesByCourseId(courseId)
.onErrorResume(Flux::error)
.switchIfEmpty(Flux.error(new RuntimeException("No quiz found with provided courseId")))
.flatMap(
y -> {
final Flux<QuestionResponseDto> question =
getQuestionWithoutAnswer(y.id().toString()).onErrorResume(Mono::error);
return Flux.zip(Mono.just(y), question);
})
.flatMap(
tuple -> {
var r = QuestionResponseDto.builder()
.id(tuple.getT2().id())
.title(tuple.getT2().title())
.answers(tuple.getT2().answers())
.build();
final Set<QuestionResponseDto> questions =
Stream.of(
tuple.getT1().questions(),
Set.of(r))
.flatMap(Stream::ofNullable)
.flatMap(Collection::stream)
.collect(Collectors.toSet());
var quiz = tuple.getT1();
quiz = quiz.withQuestions(questions);
return Flux.just(quiz);
})
.flatMap(quiz-> Flux.zip(Flux.just(quiz), combineQuestionsWithAnswers(quiz)))
.flatMap(tuple-> {
var q = tuple.getT1();
q = q.withQuestions(Set.of(tuple.getT2()));
return Flux.just(q);
});
}
private Flux<QuestionResponseDto> combineQuestionsWithAnswers(QuizWithoutResults quiz) {
return Flux.fromIterable(quiz.questions())
.flatMap(question-> Flux.zip(Mono.just(question), getAnswers(question.id().toString())))
.flatMap(x-> {
var question = x.getT1();
question = question.withAnswers(Stream.concat(x.getT1().answers().stream(), Set.of(x.getT2()).stream())
.flatMap(Stream::ofNullable)
.collect(Collectors.toSet()));
return Flux.just(question);
});
}
@Timed("getAllQuizEntitiesByCourseId")
Flux<QuizWithoutResults> getAllQuizEntitiesByCourseId(String courseId) {
//language=PostgreSQL
String query =
"""
select qi.* from unnest(array(select c.quiz_ids from courses c where c.id::text = $1)) quiz_id
join quizzes qi on qi.id=quiz_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", courseId)
.map(QuizAdapters.QUIZ_FROM_ROW_MAP::apply)
.all();
}
@Timed("getAllQuestionEntitiesByQuizId")
Flux<QuestionResponseDto> getQuestionWithoutAnswer(String quizId) {
//language=PostgreSQL
String query = """
select qs.* from unnest(array(select qi.question_ids from quizzes qi where qi.id::text = $1)) question_id
join questions qs on qs.id=question_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", quizId)
.map(QuizAdapters.QUESTION_FROM_ROW_MAP::apply)
.all();
}
@Timed("getAnswers")
Flux<AnswerDto> getAnswers(String questionId) {
//language=PostgreSQL
String query = """
select a.* from unnest(array(select qs.answer_ids from questions qs where qs.id::text = $1)) answer_id
join answers a on a.id=answer_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", questionId)
.map(QuizAdapters.ANSWER_FROM_ROW_MAP::apply)
.all();
}
}
因此，我尝试仅返回此测试功能的结果，该功能运行良好
@Timed("getAllQuestionEntitiesByQuizId")
public Flux<QuestionResponseDto> testFetch(String quizId) {
//language=PostgreSQL
String query = """
select qs.* from unnest(array(select qi.question_ids from quizzes qi where qi.id::text = '409a1c2b-b1e5-42a7-b2ae-58212aaf3b37')) question_id
join questions qs on qs.id=question_id
""";
return client.getDatabaseClient().sql(query)
.map(QuizAdapters.QUESTION_FROM_ROW_MAP::apply)
.all();
}
老实说，在这种情况下我会使用 .block() 因为我需要另一个表中包含的信息才能继续前进，它们是 3 个表，但是这种可能性已被消除。
对于每个测验，我都需要问题集，对于每个问题，我都需要答案。
你会怎么做？
编辑
我已将上面的代码更改为：
package io.deviad.ripeti.webapp.application.query;
import io.deviad.ripeti.webapp.adapter.QuizAdapters;
import io.deviad.ripeti.webapp.api.command.AnswerDto;
import io.deviad.ripeti.webapp.api.queries.QuestionResponseDto;
import io.deviad.ripeti.webapp.api.queries.QuizWithoutResults;
import io.micrometer.core.annotation.Timed;
import lombok.AllArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Lazy;
import org.springframework.data.r2dbc.core.R2dbcEntityOperations;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.stream.Collectors;
import java.util.stream.Stream;
@Service
@Slf4j
@Lazy
@AllArgsConstructor
public class QuizQueryService {
R2dbcEntityOperations client;
@Transactional(readOnly = true)
public Mono<Map<UUID, Collection<QuizWithoutResults>>> getAllQuizzes(String courseId) {
return getAllQuizEntitiesByCourseId(courseId)
.onErrorResume(Flux::error)
.switchIfEmpty(Flux.error(new RuntimeException("No quiz found with provided courseId")))
.flatMap(
y -> {
final Flux<QuestionResponseDto> questions =
getQuestionWithoutAnswer(y.id().toString()).onErrorResume(Mono::error);
return Flux.zip(Mono.defer(()->Mono.just(y)).repeat(), questions);
})
.flatMap(
tuple -> {
var r = QuestionResponseDto.builder()
.id(tuple.getT2().id())
.title(tuple.getT2().title())
.answers(tuple.getT2().answers())
.build();
final Set<QuestionResponseDto> questions =
Stream.of(
tuple.getT1().questions(),
Set.of(r))
.flatMap(Stream::ofNullable)
.flatMap(Collection::stream)
.collect(Collectors.toSet());
var quiz = tuple.getT1();
quiz = quiz.withQuestions(questions);
return Flux.just(quiz);
})
.flatMap(quiz-> Flux.zip(Mono.defer(()->Mono.just(quiz)).repeat(), combineQuestionsWithAnswers(quiz)))
.flatMap(tuple-> {
var q = tuple.getT1();
q = q.withQuestions(Set.of(tuple.getT2()));
return Flux.just(q);
})
.collectMultimap(QuizWithoutResults::id);
}
private Flux<QuestionResponseDto> combineQuestionsWithAnswers(QuizWithoutResults quiz) {
return Flux.fromIterable(quiz.questions())
.flatMap(question-> Flux.zip(Mono.defer(()->Mono.just(question)).repeat(), getAnswers(question.id().toString())))
.flatMap(x-> {
var question = x.getT1();
question = question.withAnswers(Stream.concat(x.getT1().answers().stream(), Set.of(x.getT2()).stream())
.flatMap(Stream::ofNullable)
.collect(Collectors.toSet()));
return Flux.just(question);
});
}
@Timed("getAllQuizEntitiesByCourseId")
Flux<QuizWithoutResults> getAllQuizEntitiesByCourseId(String courseId) {
//language=PostgreSQL
String query =
"""
select qi.* from unnest(array(select c.quiz_ids from courses c where c.id::text = $1)) quiz_id
join quizzes qi on qi.id=quiz_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", courseId)
.map(QuizAdapters.QUIZ_FROM_ROW_MAP::apply)
.all();
}
@Timed("getAllQuestionEntitiesByQuizId")
Flux<QuestionResponseDto> getQuestionWithoutAnswer(String quizId) {
//language=PostgreSQL
String query = """
select qs.* from unnest(array(select qi.question_ids from quizzes qi where qi.id::text = $1)) question_id
join questions qs on qs.id=question_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", quizId)
.map(QuizAdapters.QUESTION_FROM_ROW_MAP::apply)
.all();
}
@Timed("getAnswers")
Flux<AnswerDto> getAnswers(String questionId) {
//language=PostgreSQL
String query = """
select a.* from unnest(array(select qs.answer_ids from questions qs where qs.id::text = $1)) answer_id
join answers a on a.id=answer_id
""";
return client.getDatabaseClient().sql(query)
.bind("$1", questionId)
.map(QuizAdapters.ANSWER_FROM_ROW_MAP::apply)
.all();
}
}
这是邮递员的结果：
{
"409a1c2b-b1e5-42a7-b2ae-58212aaf3b37": [
{
"id": "409a1c2b-b1e5-42a7-b2ae-58212aaf3b37",
"quizName": "test quiz name",
"quizContent": "test quiz content",
"questions": [
{
"id": "ca454179-83fe-4c11-aedf-23cfd415bb04",
"title": "question 2",
"answers": [
{
"id": "2d7e47ad-b34d-4d44-b931-f16a88976c3d",
"title": "Is it a good day?",
"correct": true
}
]
}
]
},
{
"id": "409a1c2b-b1e5-42a7-b2ae-58212aaf3b37",
"quizName": "test quiz name",
"quizContent": "test quiz content",
"questions": [
{
"id": "ca454179-83fe-4c11-aedf-23cfd415bb04",
"title": "question 2",
"answers": [
{
"id": "7cf65bad-6f24-4a9a-9278-c5a3ce27e750",
"title": "answer 2",
"correct": true
}
]
}
]
},
{
"id": "409a1c2b-b1e5-42a7-b2ae-58212aaf3b37",
"quizName": "test quiz name",
"quizContent": "test quiz content",
"questions": [
{
"id": "c11ee15c-7792-41ce-b537-f9ef6d695b33",
"title": "question name",
"answers": [
{
"id": "2d7e47ad-b34d-4d44-b931-f16a88976c3d",
"title": "Is it a good day?",
"correct": true
}
]
}
]
},
{
"id": "409a1c2b-b1e5-42a7-b2ae-58212aaf3b37",
"quizName": "test quiz name",
"quizContent": "test quiz content",
"questions": [
{
"id": "c11ee15c-7792-41ce-b537-f9ef6d695b33",
"title": "question name",
"answers": [
{
"id": "7cf65bad-6f24-4a9a-9278-c5a3ce27e750",
"title": "answer 2",
"correct": true
}
]
}
]
}
],
"ec9fa95f-624d-4ba0-9b06-0ac3fd4c0679": [
{
"id": "ec9fa95f-624d-4ba0-9b06-0ac3fd4c0679",
"quizName": "mannaggia",
"quizContent": "alla miseria",
"questions": [
{
"id": "ca454179-83fe-4c11-aedf-23cfd415bb04",
"title": "question 2",
"answers": [
{
"id": "2d7e47ad-b34d-4d44-b931-f16a88976c3d",
"title": "Is it a good day?",
"correct": true
}
]
}
]
},
{
"id": "ec9fa95f-624d-4ba0-9b06-0ac3fd4c0679",
"quizName": "mannaggia",
"quizContent": "alla miseria",
"questions": [
{
"id": "ca454179-83fe-4c11-aedf-23cfd415bb04",
"title": "question 2",
"answers": [
{
"id": "7cf65bad-6f24-4a9a-9278-c5a3ce27e750",
"title": "answer 2",
"correct": true
}
]
}
]
},
{
"id": "ec9fa95f-624d-4ba0-9b06-0ac3fd4c0679",
"quizName": "mannaggia",
"quizContent": "alla miseria",
"questions": [
{
"id": "c11ee15c-7792-41ce-b537-f9ef6d695b33",
"title": "question name",
"answers": [
{
"id": "2d7e47ad-b34d-4d44-b931-f16a88976c3d",
"title": "Is it a good day?",
"correct": true
}
]
}
]
},
{
"id": "ec9fa95f-624d-4ba0-9b06-0ac3fd4c0679",
"quizName": "mannaggia",
"quizContent": "alla miseria",
"questions": [
{
"id": "c11ee15c-7792-41ce-b537-f9ef6d695b33",
"title": "question name",
"answers": [
{
"id": "7cf65bad-6f24-4a9a-9278-c5a3ce27e750",
"title": "answer 2",
"correct": true
}
]
}
]
}
]
}
现在我需要了解如何将这些问题和答案合并到一个集合中。