added sequence_pk_generator implementation

include/matador/query/abstract_pk_generator.hpp

@@ -0,0 +1,19 @@
+#ifndef MATADOR_ABSTRACT_PK_GENERATOR_HPP
+#define MATADOR_ABSTRACT_PK_GENERATOR_HPP
+
+#include "matador/utils/error.hpp"
+#include "matador/utils/result.hpp"
+
+#include <cstdint>
+
+namespace matador::sql {
+class executor;
+}
+namespace matador::query {
+class abstract_pk_generator {
+public:
+  virtual ~abstract_pk_generator() = default;
+  virtual utils::result<int64_t, utils::error> next_id(const sql::executor& exec) = 0;
+};
+}
+#endif //MATADOR_ABSTRACT_PK_GENERATOR_HPP

include/matador/query/intermediates/fetchable_query.hpp

@@ -61,8 +61,7 @@ public:
   [[nodiscard]] utils::result<std::optional<sql::record>, utils::error> fetch_one(const sql::executor &exec) const;
 
   template<typename Type>
-  utils::result<std::optional<Type>, utils::error> fetch_value(const sql::executor &exec)
+  utils::result<std::optional<Type>, utils::error> fetch_value(const sql::executor &exec) {
-  {
     const auto result = fetch_one(exec);
     if (!result.is_ok()) {
       return utils::failure(result.err());

include/matador/query/sequence_pk_generator.hpp

@@ -0,0 +1,20 @@
+#ifndef MATADOR_SEQUENCE_PK_GENERATOR_H
+#define MATADOR_SEQUENCE_PK_GENERATOR_H
+
+#include "matador/query/abstract_pk_generator.hpp"
+#include "matador/query/intermediates/fetchable_query.hpp"
+
+#include <string>
+
+namespace matador::query {
+class sequence_pk_generator : public abstract_pk_generator {
+public:
+    explicit sequence_pk_generator(const std::string& sequence_name);
+
+    utils::result<int64_t, utils::error> next_id(const sql::executor& exec) override;
+
+private:
+    fetchable_query query_;
+};
+}
+#endif //MATADOR_SEQUENCE_PK_GENERATOR_H

source/orm/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_library(matador-orm STATIC
   ../../include/matador/orm/error_code.hpp
   ../../include/matador/orm/session.hpp
+  ../../include/matador/query/abstract_pk_generator.hpp
   ../../include/matador/query/attribute_string_writer.hpp
   ../../include/matador/query/basic_schema.hpp
   ../../include/matador/query/builder.hpp
@@ -19,6 +20,7 @@ add_library(matador-orm STATIC
   ../../include/matador/query/fk_value_extractor.hpp
   ../../include/matador/query/generator.hpp
   ../../include/matador/query/insert_query_builder.hpp
+  ../../include/matador/query/insert_query_builder.hpp
   ../../include/matador/query/intermediates/executable_query.hpp
   ../../include/matador/query/intermediates/fetchable_query.hpp
   ../../include/matador/query/intermediates/query_alter_intermediate.hpp
@@ -64,6 +66,7 @@ add_library(matador-orm STATIC
   ../../include/matador/query/query_utils.hpp
   ../../include/matador/query/schema.hpp
   ../../include/matador/query/select_query_builder.hpp
+  ../../include/matador/query/sequence_pk_generator.hpp
   ../../include/matador/query/table.hpp
   ../../include/matador/query/table_column.hpp
   ../../include/matador/query/table_constraint.hpp
@@ -159,6 +162,7 @@ add_library(matador-orm STATIC
   query/query_utils.cpp
   query/schema.cpp
   query/select_query_builder.cpp
+  query/sequence_pk_generator.cpp
   query/table.cpp
   query/table_column.cpp
   query/table_constraint.cpp
@@ -188,9 +192,7 @@ add_library(matador-orm STATIC
   sql/resolver_service.cpp
   sql/statement.cpp
   sql/statement_cache.cpp
-  ../../include/matador/query/insert_query_builder.hpp
+)
-  query/abstract_pk_generator.hpp
-  )
 
 target_include_directories(matador-orm
   PUBLIC

source/orm/query/abstract_pk_generator.hpp

@@ -1,11 +0,0 @@
-#ifndef MATADOR_ABSTRACT_PK_GENERATOR_HPP
-#define MATADOR_ABSTRACT_PK_GENERATOR_HPP
-
-namespace matador::query {
-class abstract_pk_generator {
-public:
-  virtual ~abstract_pk_generator() = default;
-  virtual unsigned int generate() = 0;
-};
-}
-#endif //MATADOR_ABSTRACT_PK_GENERATOR_HPP

source/orm/query/sequence_pk_generator.cpp

@@ -0,0 +1,19 @@
+#include "matador/query/sequence_pk_generator.hpp"
+#include "matador/query/query.hpp"
+
+#include "matador/sql/error_code.hpp"
+
+namespace matador::query {
+sequence_pk_generator::sequence_pk_generator(const std::string& sequence_name)
+: query_(query::select().nextval(sequence_name)) {
+}
+
+utils::result<int64_t, utils::error> sequence_pk_generator::next_id(const sql::executor& exec) {
+    return query_.fetch_value<int64_t>(exec).and_then([](std::optional<int64_t> id) -> utils::result<int64_t, utils::error> {
+        if (!id) {
+            return utils::failure(utils::error(sql::error_code::RETRIEVE_DATA_FAILED, "Sequence returned no value"));
+        }
+        return utils::ok(*id);
+    });
+}
+}

todo.md

@@ -17,7 +17,33 @@
 6. Add `manual_pk_generator` class 
 7. Extend `session::insert` logic to use pk generator
 8. Add generator to `schema_node` or `table` class when attaching type
-9. add `make_object`function
+
+```cpp
+struct abstract_pk_generator {
+  virtual ~abstract_pk_generator() = default;
+  virtual int64_t next_id() = 0;
+  virtual std::vector<int64_t> next_ids(int count) = 0;
+};
+
+struct sequence_pk_generator : abstract_pk_generator {
+  explicit sequence_pk_generator(const std::string& sequence_name)
+  : query_(query::query::select().nextval(sequence_name)) {}
+  int64_t next_id(sql::executor& exec) override {
+    return query_.fetch_value<int64_t>(exec);
+  }
+  std::vector<int64_t> next_ids(int count) override;
+private:
+  query::fetchable_query query_;
+};
+
+struct table_pk_generator : abstract_pk_generator {
+  explicit table_pk_generator(const std::string& table_name);
+  int64_t next_id() override;
+  std::vector<int64_t> next_ids(int count) override;
+private:
+  std::string table_name_;
+};
+```
 
 __Proposal for polymorphic classes:__
 
@@ -32,8 +58,10 @@ If all checks succeed, the requested is fetched from the database.
 
 ```cpp
 schema.attach<jobs::Payload>("payloads", make_polymorph("type"));
-schema.attach<jobs::Payload, jobs::IdPayload>("id_list_payloads", make_polymorph_type("IdPayload"));
+schema.attach<jobs::Payload, jobs::IdPayload>("id_list_payloads", {"IdPayload"});
-schema.attach<jobs::Payload, jobs::IdListPayload>("id_payloads", make_polymorph_type("IdListPayload"));
+schema.attach<jobs::Payload, jobs::IdListPayload>("id_payloads", {"IdListPayload"});
+//schema.attach<jobs::Payload, jobs::IdPayload>("id_list_payloads", make_polymorph_type("IdPayload"));
+//schema.attach<jobs::Payload, jobs::IdListPayload>("id_payloads", make_polymorph_type("IdListPayload"));
 object::object_ptr<jobs::Payload> payload;
 auto result = payload.as<jobs::IdPayload>();
 if (result.is_ok()) {