GH-2578 - Document unwinding and pipelining of mapped __properties__.

Closes #2579.

Author: michael-simons

src/test/java/org/springframework/data/neo4j/integration/issues/IssuesIT.java

@@ -119,6 +119,10 @@
 import org.springframework.data.neo4j.integration.issues.gh2576.College;
 import org.springframework.data.neo4j.integration.issues.gh2576.CollegeRepository;
 import org.springframework.data.neo4j.integration.issues.gh2576.Student;
+import org.springframework.data.neo4j.integration.issues.gh2579.ColumnNode;
+import org.springframework.data.neo4j.integration.issues.gh2579.TableAndColumnRelation;
+import org.springframework.data.neo4j.integration.issues.gh2579.TableNode;
+import org.springframework.data.neo4j.integration.issues.gh2579.TableRepository;
 import org.springframework.data.neo4j.integration.misc.ConcreteImplementationTwo;
 import org.springframework.data.neo4j.repository.config.EnableNeo4jRepositories;
 import org.springframework.data.neo4j.repository.query.QueryFragmentsAndParameters;
@@ -866,6 +870,43 @@ void listOfMapsShouldBeUsableAsArgumentsWithWorkaround(@Autowired Neo4jTemplate
 		assertThat(uuids).containsExactly(student.getGuid());
 	}
 
+	@Test
+	@Tag("GH-2579")
+	void unwindWithMergeShouldWork(@Autowired Neo4jTemplate template, @Autowired TableRepository tableRepository) {
+
+		TableNode tableNode = new TableNode();
+		tableNode.setName("t1");
+		tableNode.setSchemaName("a");
+		tableNode.setSourceName("source1");
+		tableNode = template.save(tableNode);
+
+		ColumnNode c1 = new ColumnNode();
+		c1.setName("c1");
+		c1.setSchemaName("a");
+		c1.setSourceName("source1");
+		c1.setTableName(tableNode.getName());
+		long c1Id = template.save(c1).getId();
+
+		ColumnNode c2 = new ColumnNode();
+		c2.setName("c2");
+		c2.setSchemaName("a");
+		c2.setSourceName("source2");
+		c2.setTableName(tableNode.getName());
+		long c2Id = template.save(c2).getId();
+
+		tableRepository.mergeTableAndColumnRelations(List.of(c1, c2), tableNode);
+
+		Optional<TableNode> resolvedTableNode = tableRepository.findById(tableNode.getId());
+		assertThat(resolvedTableNode)
+				.map(TableNode::getTableAndColumnRelation)
+				.hasValueSatisfying(l -> {
+					assertThat(l)
+							.map(TableAndColumnRelation::getColumnNode)
+							.map(ColumnNode::getId)
+							.containsExactlyInAnyOrder(c1Id, c2Id);
+				});
+	}
+
 	@Configuration
 	@EnableTransactionManagement
 	@EnableNeo4jRepositories(namedQueriesLocation = "more-custom-queries.properties")

src/test/java/org/springframework/data/neo4j/integration/issues/gh2579/ColumnNode.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2011-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.neo4j.integration.issues.gh2579;
+
+import lombok.Data;
+
+import org.springframework.data.neo4j.core.schema.GeneratedValue;
+import org.springframework.data.neo4j.core.schema.Id;
+import org.springframework.data.neo4j.core.schema.Node;
+
+/**
+ * @author Michael J. Simons
+ */
+@Data
+@Node("Column")
+public class ColumnNode {
+
+	@Id
+	@GeneratedValue
+	private Long id;
+
+	private String sourceName;
+
+	private String schemaName;
+
+	private String tableName;
+
+	private String name;
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh2579/TableAndColumnRelation.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2011-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.neo4j.integration.issues.gh2579;
+
+import lombok.Data;
+
+import org.springframework.data.neo4j.core.schema.RelationshipId;
+import org.springframework.data.neo4j.core.schema.RelationshipProperties;
+import org.springframework.data.neo4j.core.schema.TargetNode;
+
+/**
+ * @author Michael J. Simons
+ */
+@Data
+@RelationshipProperties
+public class TableAndColumnRelation {
+
+    @RelationshipId
+    private Long id;
+
+    @TargetNode
+    private ColumnNode columnNode;
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh2579/TableNode.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2011-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.neo4j.integration.issues.gh2579;
+
+import lombok.Data;
+
+import java.util.List;
+
+import org.springframework.data.neo4j.core.schema.GeneratedValue;
+import org.springframework.data.neo4j.core.schema.Id;
+import org.springframework.data.neo4j.core.schema.Node;
+import org.springframework.data.neo4j.core.schema.Relationship;
+
+/**
+ * @author Michael J. Simons
+ */
+@Data
+@Node("Table")
+public class TableNode {
+
+	@Id
+	@GeneratedValue
+	private Long id;
+
+	private String sourceName;
+
+	private String schemaName;
+
+	private String name;
+
+	private String tableComment;
+
+	@Relationship(type = "BELONG", direction = Relationship.Direction.INCOMING)
+	private List<TableAndColumnRelation> tableAndColumnRelation;
+}

src/test/java/org/springframework/data/neo4j/integration/issues/gh2579/TableRepository.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2011-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.neo4j.integration.issues.gh2579;
+
+import java.util.List;
+
+import org.springframework.data.neo4j.repository.Neo4jRepository;
+import org.springframework.data.neo4j.repository.query.Query;
+import org.springframework.data.repository.query.Param;
+
+/**
+ * @author Michael J. Simons
+ */
+public interface TableRepository extends Neo4jRepository<TableNode, Long> {
+
+	@Query(value = """
+		UNWIND :#{#froms} AS col
+		WITH col.__properties__ AS col, :#{#to}.__properties__ AS to
+		MERGE (c:Column {
+			sourceName: col.sourceName,
+			schemaName: col.schemaName,
+			tableName: col.tableName,
+			name: col.name
+		})
+		MERGE (t:Table {
+			sourceName: to.sourceName,
+			schemaName: to.schemaName,
+			name: to.name
+		})
+		MERGE (c) -[r:BELONG]-> (t)"""
+	)
+	void mergeTableAndColumnRelations(@Param("froms") List<ColumnNode> froms, @Param("to") TableNode to);
+}