Collection support for predicates on meta fields. (#1338)

When a derived query is being created and there is a predicate on
a meta-field ( meta().id, cas, expiry), translate that field
(i.e. id -> meta().id) *without* the bucket or collection name,
as it might apply to a collelction which we do not know yet
(for instance, if there is a withCollection() specified)..
This is fine, because in a derived query, meta() without the
bucket or collection name is unambigous.

src/main/java/org/springframework/data/couchbase/repository/query/N1qlQueryCreator.java

@@ -76,7 +76,7 @@ public class N1qlQueryCreator extends AbstractQueryCreator<Query, QueryCriteria>
 	protected QueryCriteria create(final Part part, final Iterator<Object> iterator) {
 		PersistentPropertyPath<CouchbasePersistentProperty> path = context.getPersistentPropertyPath(part.getProperty());
 		CouchbasePersistentProperty property = path.getLeafProperty();
-		return from(part, property, where(addMetaIfRequired(bucketName, path, property, entity)), iterator);
+		return from(part, property, where(addMetaIfRequired(null, path, property, entity)), iterator);
 	}
 
 	@Override
@@ -187,17 +187,28 @@ public class N1qlQueryCreator extends AbstractQueryCreator<Query, QueryCriteria>
 		}
 	}
 
+	/**
+	 * Translate meta-fields to META(bucketName).id, cas, expiry.<br>
+	 * If bucketName is null, META().id etc, <br>
+	 * If not a meta-field, just create the corresponding path
+	 *
+	 * @param bucketName
+	 * @param persistentPropertyPath
+	 * @param property
+	 * @param entity
+	 * @return N1QLExpression
+	 */
 	public static N1QLExpression addMetaIfRequired(String bucketName,
 			final PersistentPropertyPath<CouchbasePersistentProperty> persistentPropertyPath,
 			final CouchbasePersistentProperty property, final PersistentEntity entity) {
 		if (entity != null && property == entity.getIdProperty()) {
-			return path(meta(i(bucketName)), i(META_ID_PROPERTY));
+			return path(meta(bucketName != null ? i(bucketName) : x("")), i(META_ID_PROPERTY));
 		}
 		if (property == entity.getVersionProperty()) {
-			return path(meta(i(bucketName)), i(META_CAS_PROPERTY));
+			return path(meta(bucketName != null ? i(bucketName) : x("")), i(META_CAS_PROPERTY));
 		}
 		if (property.isExpirationProperty()) {
-			return path(meta(i(bucketName)), i(META_EXPIRATION_PROPERTY));
+			return path(meta(bucketName != null ? i(bucketName) : x("")), i(META_EXPIRATION_PROPERTY));
 		}
 		return x(persistentPropertyPath.toDotPath(cvtr));
 	}

src/test/java/org/springframework/data/couchbase/domain/UserColRepository.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors
+ * Copyright 2012-2022 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.
@@ -40,10 +40,13 @@ public interface UserColRepository extends CouchbaseRepository<UserCol, String>,
 
 	// CouchbaseRepositoryQueryCollectionIntegrationTests.testScopeCollectionAnnotationSwap() relies on this
 	// being commented out.
-	//<S extends UserCol> S save(S var1);
+	// <S extends UserCol> S save(S var1);
 
 	List<UserCol> findByFirstname(String firstname);
 
+	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
+	UserCol getById(String id);
+
 	List<UserCol> findByFirstnameIn(String... firstnames);
 
 	List<UserCol> findByFirstnameIn(JsonArray firstnames);

src/test/java/org/springframework/data/couchbase/repository/query/CouchbaseRepositoryQueryCollectionIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2021 the original author or authors.
+ * Copyright 2017-2022 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.
@@ -91,6 +91,16 @@ public class CouchbaseRepositoryQueryCollectionIntegrationTests extends Collecti
 		super.afterEach();
 	}
 
+	@Test
+	void findByKey() {
+		UserCol userCol = new UserCol("101", "userColFirst", "userColLast");
+		userColRepository.save(userCol);
+		UserCol found = userColRepository.getById(userCol.getId());
+		System.err.println("found: " + found);
+		assertEquals(userCol, found);
+		userColRepository.delete(found);
+	}
+
 	@Test
 	public void myTest() {
 

src/test/java/org/springframework/data/couchbase/repository/query/N1qlQueryCreatorTests.java

@@ -189,8 +189,8 @@ class N1qlQueryCreatorTests {
 				converter, bucketName);
 		Query query = creator.createQuery();
 
-		assertEquals(query.export(),
-				" WHERE " + where(x("META(`" + bucketName + "`).`id`")).isNotNull().and(i("firstname")).is("Oliver").export());
+		assertEquals(" WHERE " + where(x("META().`id`")).isNotNull().and(i("firstname")).is("Oliver").export(),
+				query.export());
 	}
 
 	@Test // https://github.com/spring-projects/spring-data-couchbase/issues/1072
@@ -204,8 +204,9 @@ class N1qlQueryCreatorTests {
 				getAccessor(getParameters(method), 1611287177404088320L, "Oliver"), queryMethod, converter, bucketName);
 		Query query = creator.createQuery();
 
-		assertEquals(query.export(), " WHERE " + where(x("META(`" + bucketName + "`).`cas`")).is(1611287177404088320L)
-				.and(i("firstname")).is("Oliver").export());
+		assertEquals(
+				" WHERE " + where(x("META().`cas`")).is(1611287177404088320L).and(i("firstname")).is("Oliver").export(),
+				query.export());
 	}
 
 	private ParameterAccessor getAccessor(Parameters<?, ?> params, Object... values) {