Support specification of a schema in Column annotations.

Closes #1099
Original pull request #1108

Author: mipo256

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/RelationalPersistentEntityImpl.java

@@ -17,6 +17,7 @@
 
 import java.util.Optional;
 
+import org.jetbrains.annotations.NotNull;
 import org.springframework.data.mapping.model.BasicPersistentEntity;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.data.util.Lazy;
@@ -29,12 +30,14 @@
  * @author Jens Schauder
  * @author Greg Turnquist
  * @author Bastian Wilhelm
+ * @author Mikhail Polivakha
  */
 class RelationalPersistentEntityImpl<T> extends BasicPersistentEntity<T, RelationalPersistentProperty>
 		implements RelationalPersistentEntity<T> {
 
 	private final NamingStrategy namingStrategy;
 	private final Lazy<Optional<SqlIdentifier>> tableName;
+	private final Lazy<Optional<SqlIdentifier>> schemaName;
 	private boolean forceQuote = true;
 
 	/**
@@ -43,16 +46,20 @@ class RelationalPersistentEntityImpl<T> extends BasicPersistentEntity<T, Relatio
 	 * @param information must not be {@literal null}.
 	 */
 	RelationalPersistentEntityImpl(TypeInformation<T> information, NamingStrategy namingStrategy) {
-
 		super(information);
+		final Optional<Table> optionalTableAnnotation = Optional.ofNullable(findAnnotation(Table.class));
 
 		this.namingStrategy = namingStrategy;
-		this.tableName = Lazy.of(() -> Optional.ofNullable( //
-				findAnnotation(Table.class)) //
-				.map(Table::value) //
-				.filter(StringUtils::hasText) //
-				.map(this::createSqlIdentifier) //
+		this.tableName = Lazy.of(() -> optionalTableAnnotation
+				.map(Table::value)
+				.filter(StringUtils::hasText)
+				.map(this::createSqlIdentifier)
 		);
+
+		this.schemaName = Lazy.of(() -> optionalTableAnnotation
+				.map(Table::schema)
+				.filter(StringUtils::hasText)
+				.map(this::createSqlIdentifier));
 	}
 
 	private SqlIdentifier createSqlIdentifier(String name) {
@@ -77,14 +84,30 @@ public void setForceQuote(boolean forceQuote) {
 	 */
 	@Override
 	public SqlIdentifier getTableName() {
-		return tableName.get().orElseGet(() -> {
-
-			String schema = namingStrategy.getSchema();
-			SqlIdentifier tableName = createDerivedSqlIdentifier(namingStrategy.getTableName(getType()));
+		final Optional<SqlIdentifier> schema = determineCurrentEntitySchema();
+		final Optional<SqlIdentifier> explicitlySpecifiedTableName = tableName.get();
+		if (schema.isPresent()) {
+			return explicitlySpecifiedTableName
+					.map(sqlIdentifier -> SqlIdentifier.from(schema.get(), sqlIdentifier))
+					.orElse(SqlIdentifier.from(schema.get(), createDerivedSqlIdentifier(namingStrategy.getTableName(getType()))));
+		} else {
+			return explicitlySpecifiedTableName.orElse(createDerivedSqlIdentifier(namingStrategy.getTableName(getType())));
+		}
+	}
 
-			return StringUtils.hasText(schema) ? SqlIdentifier.from(createDerivedSqlIdentifier(schema), tableName)
-					: tableName;
-		});
+	/**
+	 * @return Optional of {@link SqlIdentifier} representing the current entity schema. If the schema is not specified neither
+	 * explicitly, nor via {@link NamingStrategy}, then return {@link Optional#empty()}
+	 */
+	@NotNull
+	private Optional<SqlIdentifier> determineCurrentEntitySchema() {
+		final Optional<SqlIdentifier> explicitlySpecifiedSchema = schemaName.get();
+		if (explicitlySpecifiedSchema.isPresent()) {
+			return explicitlySpecifiedSchema;
+		}
+		return StringUtils.hasText(namingStrategy.getSchema())
+						? Optional.of(createDerivedSqlIdentifier(namingStrategy.getSchema()))
+						: Optional.empty();
 	}
 
 	/*

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/Table.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.relational.core.mapping;
 
+import org.springframework.core.annotation.AliasFor;
+
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Inherited;
@@ -27,6 +29,7 @@
  *
  * @author Kazuki Shimizu
  * @author Bastian Wilhelm
+ * @author Mikhail Polivakha
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.TYPE)
@@ -37,5 +40,23 @@
 	/**
 	 * The mapping table name.
 	 */
+	@AliasFor("name")
 	String value() default "";
-}
+
+	/**
+	 * The mapping table name.
+	 */
+	@AliasFor("value")
+	String name() default "";
+
+	/**
+	 * Name of the schema (or user, for example in case of oracle), in which this table resides in
+	 * The behavior is the following: <br/>
+	 * If the {@link Table#schema()} is specified, then it will be
+	 * used as a schema of current table, i.e. as a prefix to the name of the table, which can
+	 * be specified in {@link Table#value()}. <br/>
+	 * If the {@link Table#schema()} is not specified, then spring data will assume the default schema,
+	 * The default schema itself can be provided by the means of {@link NamingStrategy#getSchema()}
+	 */
+	String schema() default "";
+}

spring-data-relational/src/test/java/org/springframework/data/relational/core/mapping/RelationalPersistentEntityImplUnitTests.java

@@ -31,6 +31,7 @@
  * @author Kazuki Shimizu
  * @author Bastian Wilhelm
  * @author Mark Paluch
+ * @author Mikhail Polivakha
  */
 public class RelationalPersistentEntityImplUnitTests {
 
@@ -72,6 +73,33 @@ public void namingStrategyWithSchemaReturnsCompositeTableName() {
 				.isEqualTo("\"MY_SCHEMA\".\"DUMMY_ENTITY_WITH_EMPTY_ANNOTATION\"");
 	}
 
+	@Test // DATAJDBC-1099
+	void testRelationalPersistentEntitySchemaNameChoice() {
+		mappingContext = new RelationalMappingContext(NamingStrategyWithSchema.INSTANCE);
+		final RelationalPersistentEntity<?> persistentEntity = mappingContext.getPersistentEntity(EntityWithExplicitSchema.class);
+		final SqlIdentifier tableName = persistentEntity.getTableName();
+		assertThat(tableName).isEqualTo(SqlIdentifier.from(SqlIdentifier.quoted("DART_VADER"), quoted("I_AM_THE_SENATE")));
+		assertThat(tableName.toString()).isEqualTo("\"DART_VADER\".\"I_AM_THE_SENATE\"");
+	}
+
+	@Test // DATAJDBC-1099
+	void testRelationalPersistentEntityTableOnlySchemaSpecified() {
+		final RelationalPersistentEntity<?> persistentEntity = mappingContext.getPersistentEntity(EntityWithSchemaFromNamingStrategy.class);
+		final SqlIdentifier tableName = persistentEntity.getTableName();
+		assertThat(tableName).isEqualTo(SqlIdentifier.from(quoted("ANAKYN_SKYWALKER"), quoted("ENTITY_WITH_SCHEMA_FROM_NAMING_STRATEGY")));
+		assertThat(tableName.toString()).isEqualTo("\"ANAKYN_SKYWALKER\".\"ENTITY_WITH_SCHEMA_FROM_NAMING_STRATEGY\"");
+	}
+
+	@Table(schema = "ANAKYN_SKYWALKER")
+	static class EntityWithSchemaFromNamingStrategy {
+		@Id private Long id;
+	}
+
+	@Table(schema = "DART_VADER", name = "I_AM_THE_SENATE")
+	static class EntityWithExplicitSchema {
+		@Id private Long id;
+	}
+
 	@Table("dummy_sub_entity")
 	static class DummySubEntity {
 		@Id @Column("renamedId") Long id;