Support of QueryByExampleExecutor#findAll(...).

This commit introduces the find by example method `findAll(...)` to spring-data-jdbc. MyBatis implementation is missing since I do not have the knowledge for this.

Related tickets spring-projects#1192

Author: DiegoKrupitza

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateOperations.java

@@ -167,4 +167,14 @@ public interface JdbcAggregateOperations {
 	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if more than one match found.
 	 */
 	<T> Optional<T> selectOne(Example<T> example);
+
+	/**
+	 * Execute a {@code SELECT} query and convert the resulting items to a {@link Iterable} that is sorted.
+	 *
+	 * @param example must not be null
+	 * @param sort the sorting that should be used on the result.
+	 * @return a non-null sorted list with all the matching results.
+	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if more than one match found.
+	 */
+	<T> Iterable<T> select(Example<T> example, Sort sort);
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateTemplate.java

@@ -270,6 +270,13 @@ public <T> Optional<T> selectOne(Example<T> example) {
 		return accessStrategy.selectOne(query, probeType);
 	}
 
+	@Override public <T> Iterable<T> select(Example<T> example, Sort sort) {
+		Query query = this.exampleMapper.getMappedExample(example).sort(sort);
+		Class<T> probeType = example.getProbeType();
+
+		return accessStrategy.select(query, probeType);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.jdbc.core.JdbcAggregateOperations#findAll(java.lang.Class)

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/CascadingDataAccessStrategy.java

@@ -216,6 +216,11 @@ public <T> Optional<T> selectOne(Query query, Class<T> probeType) {
 		return collect(das -> das.selectOne(query, probeType));
 	}
 
+	@Override
+	public <T> Iterable<T> select(Query query, Class<T> probeType) {
+		return collect(das -> das.select(query, probeType));
+	}
+
 	private <T> T collect(Function<DataAccessStrategy, T> function) {
 
 		// Keep <T> as Eclipse fails to compile if <> is used.

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/DataAccessStrategy.java

@@ -239,4 +239,13 @@ Iterable<Object> findAllByPath(Identifier identifier,
 	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if more than one match found.
 	 */
 	<T> Optional<T> selectOne(Query query, Class<T> probeType);
+
+	/**
+	 * Execute a {@code SELECT} query and convert the resulting items to a {@link Iterable}.
+	 *
+	 * @param query must not be {@literal null}.
+	 * @return a non null list with all the matching results.
+	 * @throws org.springframework.dao.IncorrectResultSizeDataAccessException if more than one match found.
+	 */
+	<T> Iterable<T> select(Query query, Class<T> probeType);
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/DefaultDataAccessStrategy.java

@@ -437,7 +437,7 @@ public <T> Iterable<T> findAll(Class<T> domainType, Pageable pageable) {
 	@Override
 	public <T> Optional<T> selectOne(Query query, Class<T> probeType) {
 		MapSqlParameterSource parameterSource = new MapSqlParameterSource();
-		String sqlQuery = sql(probeType).selectOne(query, parameterSource);
+		String sqlQuery = sql(probeType).selectByQuery(query, parameterSource);
 
 		T foundObject;
 		try {
@@ -449,6 +449,14 @@ public <T> Optional<T> selectOne(Query query, Class<T> probeType) {
 		return Optional.ofNullable(foundObject);
 	}
 
+	@Override
+	public <T> Iterable<T> select(Query query, Class<T> probeType) {
+		MapSqlParameterSource parameterSource = new MapSqlParameterSource();
+		String sqlQuery = sql(probeType).selectByQuery(query, parameterSource);
+
+		return operations.query(sqlQuery, parameterSource, (RowMapper<T>) getEntityRowMapper(probeType));
+	}
+
 	private <S, T> SqlIdentifierParameterSource getParameterSource(@Nullable S instance,
 			RelationalPersistentEntity<S> persistentEntity, String prefix,
 			Predicate<RelationalPersistentProperty> skipProperty, IdentifierProcessing identifierProcessing) {

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/DelegatingDataAccessStrategy.java

@@ -212,6 +212,11 @@ public <T> Optional<T> selectOne(Query query, Class<T> probeType) {
 		return delegate.selectOne(query, probeType);
 	}
 
+	@Override
+	public <T> Iterable<T> select(Query query, Class<T> probeType) {
+		return delegate.select(query, probeType);
+	}
+
 	/**
 	 * Must be called exactly once before calling any of the other methods.
 	 *

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/SqlGenerator.java

@@ -733,7 +733,7 @@ private OrderByField orderToOrderByField(Sort.Order order) {
 	 * @param parameterSource the source for holding the bindings
 	 * @return a non null query string.
 	 */
-	public String selectOne(Query query, MapSqlParameterSource parameterSource) {
+	public String selectByQuery(Query query, MapSqlParameterSource parameterSource) {
 
 		Assert.notNull(parameterSource, "parameterSource must not be null");
 
@@ -811,12 +811,12 @@ Column getParentId() {
 		@Override
 		public boolean equals(Object o) {
 
-			if (this == o) return true;
-			if (o == null || getClass() != o.getClass()) return false;
+			if (this == o)
+				return true;
+			if (o == null || getClass() != o.getClass())
+				return false;
 			Join join = (Join) o;
-			return joinTable.equals(join.joinTable) &&
-					joinColumn.equals(join.joinColumn) &&
-					parentId.equals(join.parentId);
+			return joinTable.equals(join.joinTable) && joinColumn.equals(join.joinColumn) && parentId.equals(join.parentId);
 		}
 
 		@Override
@@ -827,11 +827,7 @@ public int hashCode() {
 		@Override
 		public String toString() {
 
-			return "Join{" +
-					"joinTable=" + joinTable +
-					", joinColumn=" + joinColumn +
-					", parentId=" + parentId +
-					'}';
+			return "Join{" + "joinTable=" + joinTable + ", joinColumn=" + joinColumn + ", parentId=" + parentId + '}';
 		}
 	}
 

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/mybatis/MyBatisDataAccessStrategy.java

@@ -374,6 +374,13 @@ public <T> Optional<T> selectOne(Query query, Class<T> probeType) {
 		return Optional.empty();
 	}
 
+	@Override
+	public <T> Iterable<T> select(Query query, Class<T> probeType) {
+		// TODO: DIEGO find help for this one
+		// I have zero MyBatis knowledge.
+		return null;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.jdbc.core.DataAccessStrategy#count(java.lang.Class)

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/support/SimpleJdbcRepository.java

@@ -206,14 +206,10 @@ public <S extends T> Iterable<S> findAll(Example<S> example) {
 
 	@Override
 	public <S extends T> Iterable<S> findAll(Example<S> example, Sort sort) {
-		/*Assert.notNull(example, "Example must not be null!");
+		Assert.notNull(example, "Example must not be null!");
 		Assert.notNull(sort, "Sort must not be null!");
-		
-		Query query = this.exampleMapper.getMappedExample(example).sort(sort);
-		
-		return this.entityOperations.select(query, example.getProbeType());*/
-		// TODO: impl
-		return null;
+
+		return this.entityOperations.select(example,sort);
 	}
 
 	@Override

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/convert/SqlGeneratorUnitTests.java

@@ -28,6 +28,7 @@
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.ReadOnlyProperty;
 import org.springframework.data.annotation.Version;
+import org.springframework.data.domain.Example;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -46,10 +47,13 @@
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
 import org.springframework.data.relational.core.mapping.RelationalPersistentEntity;
 import org.springframework.data.relational.core.mapping.RelationalPersistentProperty;
+import org.springframework.data.relational.core.query.Criteria;
+import org.springframework.data.relational.core.query.Query;
 import org.springframework.data.relational.core.sql.Aliased;
 import org.springframework.data.relational.core.sql.LockMode;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.data.relational.core.sql.Table;
+import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 
 /**
  * Unit tests for the {@link SqlGenerator}.
@@ -64,6 +68,7 @@
  * @author Myeonghyeon Lee
  * @author Mikhail Polivakha
  * @author Chirag Tailor
+ * @author Diego Krupitza
  */
 class SqlGeneratorUnitTests {
 
@@ -250,7 +255,8 @@ void findAllSortedWithNullHandling_resolvesNullHandlingWhenDialectSupportsIt() {
 
 		SqlGenerator sqlGenerator = createSqlGenerator(DummyEntity.class, PostgresDialect.INSTANCE);
 
-		String sql = sqlGenerator.getFindAll(Sort.by(new Sort.Order(Sort.Direction.ASC, "name", Sort.NullHandling.NULLS_LAST)));
+		String sql = sqlGenerator
+				.getFindAll(Sort.by(new Sort.Order(Sort.Direction.ASC, "name", Sort.NullHandling.NULLS_LAST)));
 
 		assertThat(sql).contains("ORDER BY \"dummy_entity\".\"x_name\" ASC NULLS LAST");
 	}
@@ -260,7 +266,8 @@ void findAllSortedWithNullHandling_ignoresNullHandlingWhenDialectDoesNotSupportI
 
 		SqlGenerator sqlGenerator = createSqlGenerator(DummyEntity.class, SqlServerDialect.INSTANCE);
 
-		String sql = sqlGenerator.getFindAll(Sort.by(new Sort.Order(Sort.Direction.ASC, "name", Sort.NullHandling.NULLS_LAST)));
+		String sql = sqlGenerator
+				.getFindAll(Sort.by(new Sort.Order(Sort.Direction.ASC, "name", Sort.NullHandling.NULLS_LAST)));
 
 		assertThat(sql).endsWith("ORDER BY dummy_entity.x_name ASC");
 	}
@@ -716,6 +723,25 @@ void columnForReferencedEntityWithoutId() {
 						SqlIdentifier.quoted("child"), SqlIdentifier.quoted("CHILD_PARENT_OF_NO_ID_CHILD"));
 	}
 
+	@Test
+	void selectByQueryValidTest() {
+		final SqlGenerator sqlGenerator = createSqlGenerator(DummyEntity.class);
+
+		DummyEntity probe = new DummyEntity();
+		probe.name = "Diego";
+
+		Criteria criteria = Criteria.where("name").is(probe.name);
+		Query query = Query.query(criteria);
+
+		MapSqlParameterSource parameterSource = new MapSqlParameterSource();
+
+		String generatedSQL = sqlGenerator.selectByQuery(query, parameterSource);
+		assertThat(generatedSQL).isNotNull().contains(":x_name");
+
+		assertThat(parameterSource.getValues()) //
+				.containsOnly(entry("x_name", probe.name));
+	}
+
 	private SqlIdentifier getAlias(Object maybeAliased) {
 
 		if (maybeAliased instanceof Aliased) {
@@ -737,7 +763,8 @@ private PersistentPropertyPath<RelationalPersistentProperty> getPath(String path
 	@SuppressWarnings("unused")
 	static class DummyEntity {
 
-		@Column("id1") @Id Long id;
+		@Column("id1")
+		@Id Long id;
 		String name;
 		ReferencedEntity ref;
 		Set<Element> elements;
@@ -810,7 +837,8 @@ static class EntityWithQuotedColumnName {
 
 		// these column names behave like single double quote in the name since the get quoted and then doubling the double
 		// quote escapes it.
-		@Id @Column("test\"\"_@id") Long id;
+		@Id
+		@Column("test\"\"_@id") Long id;
 		@Column("test\"\"_@123") String name;
 	}
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/JdbcRepositoryIntegrationTests.java

@@ -611,7 +611,7 @@ void findOneByExampleMultipleMatchShouldGetOne() {
 		DummyEntity dummyEntity2 = createDummyEntity();
 		repository.save(dummyEntity2);
 
-		Example<DummyEntity> example = Example.of(new DummyEntity());
+		Example<DummyEntity> example = Example.of(createDummyEntity());
 
 		assertThatThrownBy(() -> repository.findOne(example)).isInstanceOf(IncorrectResultSizeDataAccessException.class)
 				.hasMessageContaining("expected 1, actual 2");
@@ -632,6 +632,67 @@ void findOneByExampleShouldGetNone() {
 		assertThat(foundExampleDiego).isNotPresent();
 	}
 
+	@Test
+	void findAllByExampleShouldGetOne() {
+
+		DummyEntity dummyEntity1 = createDummyEntity();
+		dummyEntity1.setFlag(true);
+
+		repository.save(dummyEntity1);
+
+		DummyEntity dummyEntity2 = createDummyEntity();
+		dummyEntity2.setName("Diego");
+
+		repository.save(dummyEntity2);
+
+		Example<DummyEntity> example = Example.of(new DummyEntity("Diego"));
+
+		Iterable<DummyEntity> allFound = repository.findAll(example);
+
+		assertThat(allFound) //
+				.isNotNull() //
+				.hasSize(1) //
+				.extracting(DummyEntity::getName) //
+				.containsExactly(example.getProbe().getName());
+	}
+
+	@Test
+	void findAllByExampleMultipleMatchShouldGetOne() {
+
+		DummyEntity dummyEntity1 = createDummyEntity();
+		repository.save(dummyEntity1);
+
+		DummyEntity dummyEntity2 = createDummyEntity();
+		repository.save(dummyEntity2);
+
+		Example<DummyEntity> example = Example.of(createDummyEntity());
+
+		Iterable<DummyEntity> allFound = repository.findAll(example);
+
+		assertThat(allFound) //
+				.isNotNull() //
+				.hasSize(2) //
+				.extracting(DummyEntity::getName) //
+				.containsOnly(example.getProbe().getName());
+	}
+
+	@Test
+	void findAllByExampleShouldGetNone() {
+
+		DummyEntity dummyEntity1 = createDummyEntity();
+		dummyEntity1.setFlag(true);
+
+		repository.save(dummyEntity1);
+
+		Example<DummyEntity> example = Example.of(new DummyEntity("NotExisting"));
+
+		Iterable<DummyEntity> allFound = repository.findAll(example);
+
+		assertThat(allFound) //
+				.isNotNull() //
+				.isEmpty();
+	}
+
 	private Instant createDummyBeforeAndAfterNow() {
 
 		Instant now = Instant.now();