diff --git a/demo/work.cpp b/demo/work.cpp
index 9772fdc..1d73a3a 100644
--- a/demo/work.cpp
+++ b/demo/work.cpp
@@ -21,18 +21,10 @@
 
 #include "matador/sql/connection.hpp"
 
+#include "matador/query/schema.hpp"
+
 #include "matador/orm/session.hpp"
 
-template <> struct matador::utils::data_type_traits<work::core::timestamp, void> {
-    static basic_type type(std::size_t /*size*/) { return basic_type::UInt64; }
-    static void read_value(attribute_reader &/*reader*/, const char * /*id*/, size_t /*index*/, nullptr_t &/*value*/) {
-
-    }
-    static void bind_value(attribute_writer &/*binder*/, size_t /*index*/, nullptr_t &/*value*/) {
-
-    }
-};
-
 template <> struct matador::utils::data_type_traits<work::core::UserInfo, void> {
     static basic_type type(std::size_t /*size*/) { return basic_type::UInt64; }
     static void read_value(attribute_reader &/*reader*/, const char * /*id*/, size_t /*index*/, nullptr_t &/*value*/) {
@@ -70,46 +62,47 @@ using namespace work::models;
 // payload.is_polymorphic_type<jobs::IdPayload>();
 
 int main() {
-    // logger::default_min_log_level(logger::log_level::LVL_DEBUG);
-    // logger::add_log_sink(logger::create_stdout_sink());
+    logger::default_min_log_level(logger::log_level::LVL_DEBUG);
+    logger::add_log_sink(logger::create_stdout_sink());
 
     // sql::connection_pool<sql::connection> pool("postgres://news:news@127.0.0.1:15432/matador", 4);
     sql::connection_pool pool("postgres://test:test123!@127.0.0.1:5432/matador", 4);
 
-    object::repository repo("Administration");
-
-    auto result = repo.attach<admin::CollectionCenter>("collection_centers");
-    // repo.create(pool);
-    // repo.drop(pool);
-
     utils::message_bus bus;
-    orm::session ses({bus, pool});
+    // query::schema ses({bus, pool});
+    query::schema admin_schema("Administration");
 
-    result = ses.attach<admin::CollectionCenter>("collection_centers")
-        .and_then([&ses] { return ses.attach<admin::UserDirectory>("user_directories"); })
-        .and_then([&ses] { return ses.attach<admin::LdapGroupSchemaSettings>("ldap_group_schema_settings"); })
-        .and_then([&ses] { return ses.attach<admin::LdapImportSettings>("ldap_import_settings"); })
-        .and_then([&ses] { return ses.attach<admin::LdapUserSchemaSettings>("ldap_user_schema_settings"); })
-        .and_then([&ses] { return ses.attach<admin::InternalUserDirectory, admin::UserDirectory>("internal_user_directories"); })
-        .and_then([&ses] { return ses.attach<admin::LdapUserDirectory, admin::UserDirectory>("ldap_user_directories"); } )
-        .and_then([&ses] { return ses.attach<admin::LoginHistory>("login_histories"); })
-        .and_then([&ses] { return ses.attach<admin::Scenario>("scenarios"); })
-        .and_then([&ses] { return ses.attach<admin::User>("users"); })
-        .and_then([&ses] { return ses.attach<admin::UserSession>("user_sessions"); })
-        .and_then([&ses] { return ses.attach<jobs::Job>("jobs"); })
-        .and_then([&ses] { return ses.attach<jobs::Payload>("payloads"); })
-        .and_then([&ses] { return ses.attach<jobs::IdPayload, jobs::Payload>("id_list_payloads"); })
-        .and_then([&ses] { return ses.attach<jobs::IdListPayload, jobs::Payload>("id_payloads"); })
-        .and_then([&ses] { return ses.attach<jobs::Task>("tasks"); })
+    auto result = admin_schema.attach<admin::CollectionCenter>("collection_centers")
+        .and_then([&admin_schema] { return admin_schema.attach<admin::UserDirectory>("user_directories"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::LdapGroupSchemaSettings>("ldap_group_schema_settings"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::LdapImportSettings>("ldap_import_settings"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::LdapUserSchemaSettings>("ldap_user_schema_settings"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::InternalUserDirectory, admin::UserDirectory>("internal_user_directories"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::LdapUserDirectory, admin::UserDirectory>("ldap_user_directories"); } )
+        .and_then([&admin_schema] { return admin_schema.attach<admin::LoginHistory>("login_histories"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::Scenario>("scenarios"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::User>("users"); })
+        .and_then([&admin_schema] { return admin_schema.attach<admin::UserSession>("user_sessions"); })
+        .and_then([&admin_schema] { return admin_schema.attach<jobs::Job>("jobs"); })
+        .and_then([&admin_schema] { return admin_schema.attach<jobs::Payload>("payloads"); })
+        .and_then([&admin_schema] { return admin_schema.attach<jobs::IdPayload, jobs::Payload>("id_list_payloads"); })
+        .and_then([&admin_schema] { return admin_schema.attach<jobs::IdListPayload, jobs::Payload>("id_payloads"); })
+        .and_then([&admin_schema] { return admin_schema.attach<jobs::Task>("tasks"); })
     ;
-    ses.dump_schema(std::cout);
+    admin_schema.dump(std::cout);
 
     if (!result) {
         std::cout << "error: " << result.err().message() << std::endl;
         return 0;
     }
 
-    result = ses.create_schema();
+    const auto conn = pool.acquire();
+    result = admin_schema.create(*conn);
+    if (!result) {
+        std::cout << "error: " << result.err() << std::endl;
+        return 0;
+    }
+    result = admin_schema.drop(*conn);
     if (!result) {
         std::cout << "error: " << result.err() << std::endl;
         return 0;
diff --git a/demo/work/admin/CollectionCenter.hpp b/demo/work/admin/CollectionCenter.hpp
index 1e4eacd..ae3e128 100644
--- a/demo/work/admin/CollectionCenter.hpp
+++ b/demo/work/admin/CollectionCenter.hpp
@@ -11,6 +11,8 @@
 #include "matador/utils/fetch_type.hpp"
 #include "matador/utils/types.hpp"
 
+#include "matador/query/meta_table_macro.hpp"
+
 namespace work::models::admin {
 struct User;
 
@@ -45,4 +47,6 @@ struct CollectionCenter : core::Model {
 
 }
 
+META_TABLE(collection_center, COLLECTION_CENTER, id, version, name, symbol, type)
+
 #endif //COLLECTION_CENTER_HPP
diff --git a/demo/work/admin/LdapGroupSchemaSettings.hpp b/demo/work/admin/LdapGroupSchemaSettings.hpp
index f943ad6..5c94b6c 100644
--- a/demo/work/admin/LdapGroupSchemaSettings.hpp
+++ b/demo/work/admin/LdapGroupSchemaSettings.hpp
@@ -4,6 +4,7 @@
 #include "../core/Model.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 struct LdapUserDirectory;
@@ -17,7 +18,7 @@ struct LdapGroupSchemaSettings : core::Model {
     void process( Operator& op ) {
         namespace field = matador::access;
         field::process( op, *matador::base_class<Model>( this ) );
-        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::default_foreign_attributes);
+        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::CascadeAllFetchLazy);
         field::attribute( op, "group_object_filter", group_object_filter, 511 );
         field::attribute( op, "user_member_attribute", user_member_attribute, 511 );
     }
diff --git a/demo/work/admin/LdapImportSettings.hpp b/demo/work/admin/LdapImportSettings.hpp
index dcf5c34..e74a0a2 100644
--- a/demo/work/admin/LdapImportSettings.hpp
+++ b/demo/work/admin/LdapImportSettings.hpp
@@ -4,6 +4,7 @@
 #include "../core/Model.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 struct LdapUserDirectory;
@@ -18,7 +19,7 @@ struct LdapImportSettings : core::Model {
     void process( Operator& op ) {
         namespace field = matador::access;
         field::process( op, *matador::base_class<Model>( this ) );
-        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::default_foreign_attributes);
+        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::CascadeAllFetchLazy);
         field::attribute( op, "default_role", default_role, 511 );
         field::attribute( op, "sync_interval", sync_interval );
         field::attribute( op, "network_timeout", network_timeout );
diff --git a/demo/work/admin/LdapUserDirectory.hpp b/demo/work/admin/LdapUserDirectory.hpp
index 18994dc..f92f6f9 100644
--- a/demo/work/admin/LdapUserDirectory.hpp
+++ b/demo/work/admin/LdapUserDirectory.hpp
@@ -10,6 +10,7 @@
 #include "matador/object/object_ptr.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 struct LdapUserDirectory : UserDirectory {
@@ -29,11 +30,11 @@ struct LdapUserDirectory : UserDirectory {
         field::attribute( op, "schema_base_dn", schema_base_dn, 511 );
         field::attribute( op, "additional_user_base_dn", additional_user_base_dn, 511 );
         field::attribute( op, "additional_group_base_dn", additional_group_base_dn, 511 );
-        field::belongs_to( op, "user_schema_settings", user_schema_settings, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "group_schema_settings", group_schema_settings, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "import_settings", import_settings, matador::utils::default_foreign_attributes );
-        field::has_many( op, "ldap_users", users, "users_id", matador::utils::default_foreign_attributes );
-        field::has_many( op, "ldap_groups", groups, "groups_id", matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "user_schema_settings", user_schema_settings, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "group_schema_settings", group_schema_settings, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "import_settings", import_settings, matador::utils::CascadeAllFetchLazy );
+        field::has_many( op, "ldap_users", users, "users_id", matador::utils::CascadeAllFetchLazy );
+        field::has_many( op, "ldap_groups", groups, "groups_id", matador::utils::CascadeAllFetchLazy );
     }
 };
 }
diff --git a/demo/work/admin/LdapUserSchemaSettings.hpp b/demo/work/admin/LdapUserSchemaSettings.hpp
index 6e308da..609c89c 100644
--- a/demo/work/admin/LdapUserSchemaSettings.hpp
+++ b/demo/work/admin/LdapUserSchemaSettings.hpp
@@ -4,7 +4,7 @@
 #include "../core/Model.hpp"
 
 #include "matador/utils/base_class.hpp"
-
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 struct LdapUserDirectory;
@@ -20,7 +20,7 @@ struct LdapUserSchemaSettings : core::Model {
     void process( Operator& op ) {
         namespace field = matador::access;
         field::process(op, *matador::base_class<Model>( this ));
-        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::default_foreign_attributes);
+        field::has_one(op, "ldap_user_directory", ldap_user_directory, matador::utils::CascadeAllFetchLazy);
         field::attribute(op, "user_object_filter", user_object_filter, 511);
         field::attribute(op, "user_unique_id_attribute", user_unique_id_attribute, 511);
         field::attribute(op, "user_member_of_attribute", user_member_of_attribute, 511);
diff --git a/demo/work/admin/LoginHistory.hpp b/demo/work/admin/LoginHistory.hpp
index 536b8e6..49d4863 100644
--- a/demo/work/admin/LoginHistory.hpp
+++ b/demo/work/admin/LoginHistory.hpp
@@ -11,6 +11,7 @@
 
 #include "matador/utils/base_class.hpp"
 #include "matador/utils/enum_mapper.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 
@@ -39,20 +40,20 @@ static const matador::utils::enum_mapper<FailReason> FailReasonEnum({
 });
 
 struct LoginHistory : core::Model {
-    matador::object::object_ptr<User> user;
+    matador::object::object_ptr<User> client;
     matador::object::object_ptr<Scenario> scenario;
     matador::object::object_ptr<CollectionCenter> collection_center;
     std::string login_name;
     FailReason fail_reason{FailReason::NoFailReason};
-    core::timestamp login_time;
+    matador::utils::timestamp login_time;
 
     template<typename Operator>
     void process( Operator& op ) {
         namespace field = matador::access;
         field::process( op, *matador::base_class<Model>( this ) );
-        field::belongs_to( op, "user", user, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "scenario", scenario, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "collection_center", collection_center, matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "client", client, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "scenario", scenario, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "collection_center", collection_center, matador::utils::CascadeAllFetchLazy );
         field::attribute( op, "login_name", login_name, 511 );
         field::attribute( op, "fail_reason", fail_reason );
         field::attribute( op, "login_time", login_time );
diff --git a/demo/work/admin/User.hpp b/demo/work/admin/User.hpp
index 49032a1..244609d 100644
--- a/demo/work/admin/User.hpp
+++ b/demo/work/admin/User.hpp
@@ -4,11 +4,11 @@
 #include "LockType.hpp"
 
 #include "../core/Model.hpp"
-#include "../core/Types.hpp"
 
 #include "matador/object/object_ptr.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 #include "matador/utils/types.hpp"
 
 namespace work::models::admin {
@@ -20,7 +20,7 @@ struct User : core::Model {
     std::string salt;
     std::string password;
     LockType lock_type{LockType::NoLock};
-    core::timestamp locked_at;
+    matador::utils::timestamp locked_at;
     std::string lock_reason;
     std::string role;
     matador::object::object_ptr<UserDirectory> user_directory;
@@ -37,7 +37,7 @@ struct User : core::Model {
         field::attribute( op, "locked_at", locked_at );
         field::attribute( op, "lock_reason", lock_reason, 511 );
         field::attribute( op, "role", role, 63 );
-        field::belongs_to( op, "user_directory", user_directory, matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "user_directory", user_directory, matador::utils::CascadeAllFetchLazy );
     }
 };
 
diff --git a/demo/work/admin/UserSession.hpp b/demo/work/admin/UserSession.hpp
index d2b1ef7..856f37e 100644
--- a/demo/work/admin/UserSession.hpp
+++ b/demo/work/admin/UserSession.hpp
@@ -6,26 +6,26 @@
 #include "User.hpp"
 
 #include "../core/Model.hpp"
-#include "../core/Types.hpp"
 
 #include "matador/object/object_ptr.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::admin {
 struct UserSession : core::Model {
-    matador::object::object_ptr<User> user;
+    matador::object::object_ptr<User> client;
     matador::object::object_ptr<Scenario> scenario;
     matador::object::object_ptr<CollectionCenter> collection_center;
-    core::timestamp offline_since;
+    matador::utils::timestamp offline_since;
 
     template<typename Operator>
     void process( Operator& op ) {
         namespace field = matador::access;
         field::process( op, *matador::base_class<Model>( this ) );
-        field::belongs_to( op, "user", user, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "scenario", scenario, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "collection_center", collection_center, matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "client", client, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "scenario", scenario, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "collection_center", collection_center, matador::utils::CascadeAllFetchLazy );
         field::attribute( op, "offline_since", offline_since );
     }
 };
diff --git a/demo/work/core/Types.hpp b/demo/work/core/Types.hpp
deleted file mode 100644
index b793be6..0000000
--- a/demo/work/core/Types.hpp
+++ /dev/null
@@ -1,9 +0,0 @@
-#ifndef TYPES_HPP
-#define TYPES_HPP
-
-#include <chrono>
-
-namespace work::core {
-using timestamp = std::chrono::system_clock::time_point;
-}
-#endif //TYPES_HPP
diff --git a/demo/work/jobs/Job.hpp b/demo/work/jobs/Job.hpp
index 8a20840..a3c2edc 100644
--- a/demo/work/jobs/Job.hpp
+++ b/demo/work/jobs/Job.hpp
@@ -7,12 +7,12 @@
 #include "Task.hpp"
 
 #include "../core/Model.hpp"
-#include "../core/Types.hpp"
 #include "../core/UserInfo.hpp"
 
 #include "matador/object/object_ptr.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::jobs {
 
@@ -21,7 +21,7 @@ struct Job : core::Model {
     std::string description;
     JobState state;
     JobMode mode;
-    core::timestamp created_at;
+    matador::utils::timestamp created_at;
     matador::object::object_ptr<Payload> payload;
     matador::object::object_ptr<Task> task;
     core::UserInfo user_info;
@@ -35,8 +35,8 @@ struct Job : core::Model {
         field::attribute( op, "state", state );
         field::attribute( op, "mode", mode );
         field::attribute( op, "created_at", created_at );
-        field::has_one(op, "payload", payload, matador::utils::default_foreign_attributes );
-        field::belongs_to( op, "task", task, matador::utils::default_foreign_attributes );
+        field::has_one(op, "payload", payload, matador::utils::CascadeAllFetchLazy );
+        field::belongs_to( op, "task", task, matador::utils::CascadeAllFetchLazy );
         field::attribute( op, "user_info", user_info );
     }
 };
diff --git a/demo/work/jobs/Payload.hpp b/demo/work/jobs/Payload.hpp
index 0ee0922..5207acc 100644
--- a/demo/work/jobs/Payload.hpp
+++ b/demo/work/jobs/Payload.hpp
@@ -4,6 +4,7 @@
 #include "../core/Model.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::jobs {
 struct Job;
@@ -16,7 +17,7 @@ struct Payload : core::Model {
         namespace field = matador::access;
         field::process( op, *matador::base_class<Model>( this ) );
         field::attribute( op, "type", type, 255 );
-        field::belongs_to( op, "job", job, matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "job", job, matador::utils::CascadeAllFetchLazy );
     }
 };
 }
diff --git a/demo/work/jobs/Task.hpp b/demo/work/jobs/Task.hpp
index 2142935..ed69842 100644
--- a/demo/work/jobs/Task.hpp
+++ b/demo/work/jobs/Task.hpp
@@ -4,11 +4,11 @@
 #include "TaskState.hpp"
 
 #include "../core/Model.hpp"
-#include "../core/Types.hpp"
 
 #include "matador/object/object_ptr.hpp"
 
 #include "matador/utils/base_class.hpp"
+#include "matador/utils/foreign_attributes.hpp"
 
 namespace work::models::jobs {
 struct Task : core::Model {
@@ -18,8 +18,8 @@ struct Task : core::Model {
     TaskState state;
     matador::object::object_ptr<Payload> payload;
     JobMode job_mode;
-    core::timestamp start_delay;
-    core::timestamp interval;
+    matador::utils::timestamp start_delay;
+    matador::utils::timestamp interval;
     uint64_t user_session_id;
 
     template<typename Operator>
@@ -30,7 +30,7 @@ struct Task : core::Model {
         field::attribute( op, "description", description, 511 );
         field::attribute( op, "job_name", job_name, 511 );
         field::attribute( op, "state", state );
-        field::belongs_to( op, "payload", payload, matador::utils::default_foreign_attributes );
+        field::belongs_to( op, "payload", payload, matador::utils::CascadeAllFetchLazy );
         field::attribute( op, "job_mode", job_mode );
         field::attribute( op, "start_delay", start_delay );
         field::attribute( op, "interval", interval );
diff --git a/include/matador/sql/dialect.hpp b/include/matador/sql/dialect.hpp
index a1bea6d..5f0f16e 100644
--- a/include/matador/sql/dialect.hpp
+++ b/include/matador/sql/dialect.hpp
@@ -262,7 +262,8 @@ private:
     {utils::basic_type::Time, "TIME"},
     {utils::basic_type::DateTime, "DATETIME"},
     {utils::basic_type::Blob, "BLOB"},
-    {utils::basic_type::Null, "NULL"}
+    {utils::basic_type::Null, "NULL"},
+    // {utils::basic_type::Unknown, "INTEGER"}
   };
 
   sql_func_to_string_map sql_func_map_ {