diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index d1a13512d80b1cb8bca078f001987e958aa0e874..66ea8a30ae64a7433b01d76a925705303b35b650 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -82,7 +82,7 @@ if(LINTING)
             "--warnings-as-errors=*"
             "--fix")
         set(_CMAKE_CXX_CLANG_TIDY_CHECKS
-          "--checks=*,-fuchsia-*,-llvmlibc-*,-cert-err58-cpp,-cppcoreguidelines-avoid-non-const-global-variables,-cppcoreguidelines-owning-memory,-modernize-use-trailing-return-type,-google-readability-avoid-underscore-in-googletest-name,-cppcoreguidelines-avoid-magic-numbers,-readability-magic-numbers,-cppcoreguidelines-avoid-goto,-hicpp-avoid-goto,-readability-function-cognitive-complexity")
+          "--checks=*,-fuchsia-*,-llvmlibc-*,-cert-err58-cpp,-cppcoreguidelines-avoid-non-const-global-variables,-cppcoreguidelines-owning-memory,-modernize-use-trailing-return-type,-google-readability-avoid-underscore-in-googletest-name,-cppcoreguidelines-avoid-magic-numbers,-readability-magic-numbers,-cppcoreguidelines-avoid-goto,-hicpp-avoid-goto,-readability-function-cognitive-complexity,-cppcoreguidelines-pro-type-vararg,-cppcoreguidelines-pro-bounds-array-to-pointer-decay,-hicpp-no-array-decay")
     endif()
 else()
     message(STATUS "LINTING is OFF")
diff --git a/test/test_ccaosdb.cpp b/test/test_ccaosdb.cpp
index 7c952a020d01eccb3e504335596834e48c5b6e23..dbd5c48b5962c8b8e0cfc1eedc84be84b03ac920 100644
--- a/test/test_ccaosdb.cpp
+++ b/test/test_ccaosdb.cpp
@@ -2,6 +2,7 @@
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021 Florian Spreckelsen <f.spreckelsen@indiscale.com>
  * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
@@ -17,6 +18,7 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
+#include "caosdb/message_code.h"   // for MessageCode
 #include "caosdb/status_code.h"    // for StatusCode
 #include "ccaosdb.h"               // for caosdb_info_version_info, caosdb_...
 #include "gtest/gtest-message.h"   // for Message
@@ -55,8 +57,8 @@ TEST(test_ccaosdb, test_count_query) {
   EXPECT_EQ(return_code, 0);
 
   // COUNT query with an empty result
-  return_code = caosdb_transaction_transaction_query(
-    &transaction, "COUNT ENTITY WITH id='non-existing'");
+  return_code = caosdb_transaction_transaction_query(&transaction,
+                                                     "COUNT ENTITY WITH id=-1");
   EXPECT_EQ(return_code, caosdb::StatusCode::GO_ON);
 
   return_code = caosdb_transaction_transaction_execute(&transaction);
@@ -72,3 +74,145 @@ TEST(test_ccaosdb, test_count_query) {
   return_code = caosdb_transaction_delete_transaction(&transaction);
   EXPECT_EQ(return_code, 0);
 }
+
+TEST(test_ccaosdb, test_query) {
+  caosdb_connection_connection connection;
+  int return_code(
+    caosdb_connection_connection_manager_get_default_connection(&connection));
+  EXPECT_EQ(return_code, 0);
+
+  caosdb_transaction_transaction transaction;
+  return_code =
+    caosdb_connection_connection_create_transaction(&connection, &transaction);
+  EXPECT_EQ(return_code, 0);
+
+  return_code = caosdb_transaction_transaction_query(&transaction,
+                                                     "FIND ENTITY WITH id=-1");
+  EXPECT_EQ(return_code, caosdb::StatusCode::GO_ON);
+
+  return_code = caosdb_transaction_transaction_execute(&transaction);
+  EXPECT_EQ(return_code, 0);
+
+  caosdb_transaction_result_set result_set;
+  return_code =
+    caosdb_transaction_transaction_get_result_set(&transaction, &result_set);
+  EXPECT_EQ(return_code, 0);
+
+  int dummy(-1);
+  int *count = &dummy; // NOLINT
+  return_code = caosdb_transaction_result_set_size(&result_set, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 0);
+
+  return_code = caosdb_transaction_delete_transaction(&transaction);
+  EXPECT_EQ(return_code, 0);
+}
+
+TEST(test_ccaosdb, test_single_id_retrieve) {
+  caosdb_connection_connection connection;
+  int return_code(
+    caosdb_connection_connection_manager_get_default_connection(&connection));
+  EXPECT_EQ(return_code, 0);
+
+  caosdb_transaction_transaction transaction;
+  return_code =
+    caosdb_connection_connection_create_transaction(&connection, &transaction);
+  EXPECT_EQ(return_code, 0);
+
+  return_code =
+    caosdb_transaction_transaction_retrieve_by_id(&transaction, "21");
+  EXPECT_EQ(return_code, caosdb::StatusCode::GO_ON);
+
+  return_code = caosdb_transaction_transaction_execute(&transaction);
+  EXPECT_EQ(return_code, 0);
+
+  caosdb_transaction_result_set result_set;
+  return_code =
+    caosdb_transaction_transaction_get_result_set(&transaction, &result_set);
+  EXPECT_EQ(return_code, 0);
+
+  int dummy(-1);
+  int *count = &dummy; // NOLINT
+  return_code = caosdb_transaction_result_set_size(&result_set, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 1);
+
+  caosdb_entity_entity entity;
+  return_code = caosdb_transaction_result_set_at(&result_set, &entity, 0);
+  EXPECT_EQ(return_code, 0);
+
+  return_code = caosdb_entity_entity_get_errors_size(&entity, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 0);
+
+  char out[255] = {"255"}; // NOLINT
+  return_code = caosdb_entity_entity_get_name(&entity, out);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_STREQ(out, "unit");
+
+  return_code = caosdb_transaction_delete_transaction(&transaction);
+  EXPECT_EQ(return_code, 0);
+}
+
+TEST(test_ccaosdb, test_multi_id_retrieve) {
+  caosdb_connection_connection connection;
+  int return_code(
+    caosdb_connection_connection_manager_get_default_connection(&connection));
+  EXPECT_EQ(return_code, 0);
+
+  caosdb_transaction_transaction transaction;
+  return_code =
+    caosdb_connection_connection_create_transaction(&connection, &transaction);
+  EXPECT_EQ(return_code, 0);
+
+  const char *ids[] = {"20", "21", "22"}; // NOLINT
+  return_code =
+    caosdb_transaction_transaction_retrieve_by_ids(&transaction, ids, 3);
+  EXPECT_EQ(return_code, caosdb::StatusCode::GO_ON);
+
+  return_code = caosdb_transaction_transaction_execute(&transaction);
+  // Should have an error since entity 22 doesn't exist
+  EXPECT_TRUE((return_code > 0));
+
+  caosdb_transaction_result_set result_set;
+  return_code =
+    caosdb_transaction_transaction_get_result_set(&transaction, &result_set);
+  EXPECT_EQ(return_code, 0);
+
+  int dummy(-1);
+  int *count = &dummy; // NOLINT
+  return_code = caosdb_transaction_result_set_size(&result_set, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 3);
+
+  caosdb_entity_entity entity;
+  return_code = caosdb_transaction_result_set_at(&result_set, &entity, 1);
+  EXPECT_EQ(return_code, 0);
+
+  return_code = caosdb_entity_entity_get_errors_size(&entity, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 0);
+
+  char out[255] = {"255"}; // NOLINT
+  return_code = caosdb_entity_entity_get_name(&entity, out);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_STREQ(out, "unit");
+
+  caosdb_entity_entity other_entity;
+  return_code = caosdb_transaction_result_set_at(&result_set, &other_entity, 2);
+  EXPECT_EQ(return_code, 0);
+  return_code = caosdb_entity_entity_get_errors_size(&other_entity, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, 1);
+
+  caosdb_entity_message err_msg;
+  return_code = caosdb_entity_entity_get_error(&other_entity, &err_msg, 0);
+  EXPECT_EQ(return_code, 0);
+
+  return_code = caosdb_entity_message_get_code(&err_msg, count);
+  EXPECT_EQ(return_code, 0);
+  EXPECT_EQ(*count, caosdb::entity::MessageCode::ENTITY_DOES_NOT_EXIST);
+
+  return_code = caosdb_transaction_delete_transaction(&transaction);
+  EXPECT_EQ(return_code, 0);
+}