pk generator progress and sequence test progress

backends/postgres/include/postgres_connection.hpp

@@ -45,6 +45,8 @@ public:
 private:
   [[nodiscard]] static std::string generate_statement_name(const sql::query_context &query) ;
 
+  utils::result<sql::execute_result, utils::error> execute(const std::string &stmt) const;
+
 private:
   PGconn *conn_{nullptr};
 

backends/postgres/src/postgres_connection.cpp

@@ -129,6 +129,20 @@ std::string postgres_connection::generate_statement_name(const sql::query_contex
   return name.str();
 }
 
+utils::result<sql::execute_result, utils::error> postgres_connection::execute(const std::string& stmt) const {
+    PGresult *res = PQexec(conn_, stmt.c_str());
+
+    if (const auto status = PQresultStatus(res); status != PGRES_COMMAND_OK && status != PGRES_TUPLES_OK) {
+        return utils::failure(make_error(sql::error_code::FAILURE, res, conn_, "Failed to execute", stmt));
+    }
+
+    const size_t affected_rows = utils::to<size_t>(PQcmdTuples(res));
+
+    PQclear(res);
+
+    return utils::ok(sql::execute_result{affected_rows});
+}
+
 utils::result<std::unique_ptr<sql::statement_impl>, utils::error> postgres_connection::prepare(const sql::query_context &context) {
   auto statement_name = generate_statement_name(context);
 
@@ -143,9 +157,7 @@ utils::result<std::unique_ptr<sql::statement_impl>, utils::error> postgres_conne
 }
 
 utils::result<sql::execute_result, utils::error> postgres_connection::execute(const sql::query_context &context) {
-  if (context.command == sql::sql_command::Insert) {
+  return execute(context.sql);
-    // handle insert command with the primary key generator strategy
-  }
   PGresult *res = PQexec(conn_, context.sql.c_str());
 
   if (const auto status = PQresultStatus(res); status != PGRES_COMMAND_OK && status != PGRES_TUPLES_OK) {
@@ -299,7 +311,17 @@ utils::result<bool, utils::error> postgres_connection::exists(const std::string
 }
 
 utils::result<bool, utils::error> postgres_connection::sequence_exists(const std::string& schema_name, const std::string& sequence_name) {
-  return utils::ok(false);
+    const std::string sql{"SELECT to_regclass('" + schema_name + "." + sequence_name + "')"};
+    PGresult* res = PQexec(conn_, sql.c_str());
+
+    if (PQresultStatus(res) != PGRES_TUPLES_OK) {
+        return utils::failure(make_error(sql::error_code::SEQUENCE_EXISTS_FAILED, res, conn_, "Failed check if sequence exists", sql));
+    }
+
+    const bool exists = PQgetisnull(res, 0, 0) ? false : true;
+    PQclear(res);
+
+    return utils::ok(exists);
 }
 
 std::string postgres_connection::to_escaped_string(const utils::blob_type_t &value) const {

include/matador/query/abstract_pk_generator.hpp

@@ -15,6 +15,7 @@ class abstract_pk_generator {
 public:
   virtual ~abstract_pk_generator() = default;
   virtual utils::result<int64_t, utils::error> next_id(const sql::executor& exec) = 0;
+  virtual utils::result<int64_t, utils::error> current_id(const sql::executor& exec) = 0;
 
   [[nodiscard]] utils::generator_type type() const;
 

include/matador/query/intermediates/query_select_intermediate.hpp

@@ -18,6 +18,7 @@ public:
   explicit query_select_intermediate(const std::vector<table_column>& columns);
 
   fetchable_query nextval(const std::string& sequence_name);
+  fetchable_query currval(const std::string& sequence_name);
 
   template<typename... Tables>
   query_from_intermediate from(const Tables&... tables) {

include/matador/query/internal/query_parts.hpp

@@ -139,6 +139,19 @@ private:
   std::string sequence_name_;
 };
 
+class query_select_currval_part final : public query_part {
+public:
+  explicit query_select_currval_part(std::string sequence_name);
+
+  [[nodiscard]] const std::string& sequence_name() const;
+
+private:
+  void accept(query_part_visitor &visitor) override;
+
+private:
+  std::string sequence_name_;
+};
+
 
 /**
  * Represents the SQL FROM part

include/matador/query/manual_pk_generator.hpp

@@ -8,6 +8,7 @@ class manual_pk_generator : public abstract_pk_generator {
 public:
     manual_pk_generator();
     [[nodiscard]] utils::result<int64_t, utils::error> next_id(const sql::executor& exec) override;
+    [[nodiscard]] utils::result<int64_t, utils::error> current_id(const sql::executor& exec) override;
 };
 }
 #endif //MATADOR_MANUAL_PK_GENERATOR_HPP

include/matador/query/query_builder.hpp

@@ -46,6 +46,7 @@ protected:
 
   void visit(internal::query_select_part &part) override;
   void visit(internal::query_select_nextval_part &part) override;
+  void visit(internal::query_select_currval_part &part) override;
   void visit(internal::query_from_part &part) override;
   void visit(internal::query_join_table_part &part) override;
   void visit(internal::query_join_query_part &part) override;

include/matador/query/query_part_visitor.hpp

@@ -18,6 +18,7 @@ class query_add_primary_key_constraint_part;
 // Select
 class query_select_part;
 class query_select_nextval_part;
+class query_select_currval_part;
 class query_from_part;
 class query_join_table_part;
 class query_join_query_part;
@@ -76,6 +77,7 @@ public:
 
   virtual void visit(internal::query_select_part &part) = 0;
   virtual void visit(internal::query_select_nextval_part &part) = 0;
+  virtual void visit(internal::query_select_currval_part &part) = 0;
   virtual void visit(internal::query_from_part &part) = 0;
   virtual void visit(internal::query_join_table_part &part) = 0;
   virtual void visit(internal::query_join_query_part &part) = 0;

include/matador/query/sequence_pk_generator.hpp

@@ -12,9 +12,11 @@ public:
     explicit sequence_pk_generator(const std::string& sequence_name);
 
     utils::result<int64_t, utils::error> next_id(const sql::executor& exec) override;
+    utils::result<int64_t, utils::error> current_id(const sql::executor& exec) override;
 
 private:
-    fetchable_query query_;
+    fetchable_query next_id_query_;
+    fetchable_query current_id_query_;
 };
 }
 #endif //MATADOR_SEQUENCE_PK_GENERATOR_H

include/matador/query/table_pk_generator.hpp

@@ -2,15 +2,18 @@
 #define MATADOR_TABLE_PK_GENERATOR_HPP
 
 #include "matador/query/abstract_pk_generator.hpp"
+#include "matador/query/intermediates/fetchable_query.hpp"
 
 namespace matador::query {
 class table_pk_generator : public abstract_pk_generator {
 public:
     table_pk_generator(const std::string& table_name, const std::string& sequence_name);
     [[nodiscard]] utils::result<int64_t, utils::error> next_id(const sql::executor& exec) override;
+    [[nodiscard]] utils::result<int64_t, utils::error> current_id(const sql::executor& exec) override;
 
 private:
-    std::string table_name;
+    fetchable_query next_id_query_;
+    fetchable_query current_id_query_;
 };
 }
 #endif //MATADOR_TABLE_PK_GENERATOR_HPP

include/matador/sql/dialect.hpp

@@ -138,6 +138,7 @@ public:
   [[nodiscard]] const std::string& commit() const;
   [[nodiscard]] const std::string& constraint() const;
   [[nodiscard]] const std::string& create() const;
+  [[nodiscard]] const std::string& currval() const;
   [[nodiscard]] const std::string& desc() const;
   [[nodiscard]] const std::string& distinct() const;
   [[nodiscard]] const std::string& drop() const;
@@ -212,6 +213,7 @@ private:
     {dialect_token::Commit,      "COMMIT TRANSACTION"},
     {dialect_token::Constraint,  "CONSTRAINT"},
     {dialect_token::Create,      "CREATE"},
+    {dialect_token::CurrVal,     "CURRVAL"},
     {dialect_token::Desc,        "DESC"},
     {dialect_token::Distinct,    "DISTINCT"},
     {dialect_token::Drop,        "DROP"},

include/matador/sql/dialect_token.hpp

@@ -21,6 +21,7 @@ enum class dialect_token : uint8_t {
   Commit,
   Constraint,
   Create,
+  CurrVal,
   Database,
   Desc,
   Distinct,

include/matador/sql/error_code.hpp

@@ -18,6 +18,7 @@ enum class error_code : uint8_t {
   DESCRIBE_FAILED,
   TABLE_EXISTS_FAILED,
   RETRIEVE_DATA_FAILED,
+  SEQUENCE_EXISTS_FAILED,
   RESET_FAILED,
   OPEN_ERROR,
   CLOSE_ERROR,

source/orm/query/intermediates/query_select_intermediate.cpp

@@ -17,6 +17,12 @@ fetchable_query query_select_intermediate::nextval(const std::string& sequence_n
   return {context_};
 }
 
+fetchable_query query_select_intermediate::currval(const std::string& sequence_name) {
+    context_->parts.pop_back();
+    context_->parts.push_back(std::make_unique<internal::query_select_currval_part>(sequence_name));
+    return {context_};
+}
+
 query_from_intermediate query_select_intermediate::from(const std::vector<table>& tables) {
   context_->parts.push_back(std::make_unique<internal::query_from_part>(tables));
   for (const auto& tab : tables) {

source/orm/query/internal/query_parts.cpp

@@ -147,6 +147,19 @@ void query_select_nextval_part::accept(query_part_visitor& visitor) {
   visitor.visit(*this);
 }
 
+query_select_currval_part::query_select_currval_part(std::string sequence_name)
+: query_part(sql::dialect_token::NextVal)
+, sequence_name_(std::move(sequence_name)){
+}
+
+const std::string& query_select_currval_part::sequence_name() const {
+  return sequence_name_;
+}
+
+void query_select_currval_part::accept(query_part_visitor& visitor) {
+  visitor.visit(*this);
+}
+
 query_from_part::query_from_part(std::vector<table> tables)
 : query_part(sql::dialect_token::From)
 , tables_(std::move(tables)) {

source/orm/query/manual_pk_generator.cpp

@@ -10,4 +10,8 @@ manual_pk_generator::manual_pk_generator()
 utils::result<int64_t, utils::error> manual_pk_generator::next_id(const sql::executor &/*exec*/) {
   return utils::failure(utils::error(sql::error_code::FAILURE, "Manual PK generator not implemented"));
 }
+
+utils::result<int64_t, utils::error> manual_pk_generator::current_id(const sql::executor& exec) {
+  return utils::failure(utils::error(sql::error_code::FAILURE, "Manual PK generator not implemented"));
+}
 }

source/orm/query/query_builder.cpp

@@ -104,6 +104,11 @@ void query_builder::visit(internal::query_select_nextval_part& part) {
   prepare_prototype(query_.prototype, part.sequence_name());
 }
 
+void query_builder::visit(internal::query_select_currval_part& part) {
+  query_.sql += dialect_->select() + " " + dialect_->currval() + "('" + part.sequence_name() + "')";
+  prepare_prototype(query_.prototype, part.sequence_name());
+}
+
 void query_builder::visit(internal::query_from_part &part) {
   query_.table_name = part.tables().front().name();
   query_.sql += " " + dialect_->from() + " ";

source/orm/query/sequence_pk_generator.cpp

@@ -6,11 +6,21 @@
 namespace matador::query {
 sequence_pk_generator::sequence_pk_generator(const std::string& sequence_name)
 : abstract_pk_generator(utils::generator_type::Sequence)
-, query_(query::select().nextval(sequence_name)) {
+, next_id_query_(query::select().nextval(sequence_name))
+, current_id_query_(query::select().currval(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([](const std::optional<int64_t> id) -> utils::result<int64_t, utils::error> {
+    return next_id_query_.fetch_value<int64_t>(exec).and_then([](const 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);
+    });
+}
+
+utils::result<int64_t, utils::error> sequence_pk_generator::current_id(const sql::executor& exec) {
+    return current_id_query_.fetch_value<int64_t>(exec).and_then([](const 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"));
         }

source/orm/query/table_pk_generator.cpp

@@ -4,23 +4,35 @@
 #include "matador/query/error_code.hpp"
 #include "matador/query/expression/expression_operators.hpp"
 
+#include "matador/sql/error_code.hpp"
+
 namespace matador::query {
 table_pk_generator::table_pk_generator(const std::string& table_name, const std::string &sequence_name)
-: abstract_pk_generator(utils::generator_type::Table) {
+: abstract_pk_generator(utils::generator_type::Table)
-
+, next_id_query_(query::update(table_name)
-  query::update(table_name)
   .set("next_id"_col, "next_id"_col + 1)
   .where("name"_col == sequence_name)
-    .returning(("next_id"_col - 1).as("id"));
+  .returning(("next_id"_col - 1).as("id")))
-  /*
+, current_id_query_(query::select({"next_id"_col})
-  *UPDATE id_table
+  .from(table_name)
-  SET next_id = next_id + 1
+  .where("name"_col == sequence_name)
-  WHERE name = 'users'
+) {}
-  RETURNING next_id - 1 AS id;
-  */
-}
 
 utils::result<int64_t, utils::error> table_pk_generator::next_id(const sql::executor &exec) {
-  return utils::failure(utils::error{error_code::Failure});
+    return next_id_query_.fetch_value<int64_t>(exec).and_then([](const 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);
+    });
+}
+
+utils::result<int64_t, utils::error> table_pk_generator::current_id(const sql::executor& exec) {
+    return current_id_query_.fetch_value<int64_t>(exec).and_then([](const 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);
+    });
 }
 }

source/orm/sql/dialect.cpp

@@ -243,6 +243,10 @@ const std::string& dialect::nextval() const {
   return token_at(dialect_token::NextVal);
 }
 
+const std::string& dialect::currval() const {
+  return token_at(dialect_token::CurrVal);
+}
+
 const std::string &dialect::not_() const {
   return token_at(dialect_token::Not);
 }

source/orm/sql/error_code.cpp

@@ -30,6 +30,8 @@ std::string sql_category_impl::message(const int ev) const {
       return "Table exists failed";
     case error_code::RETRIEVE_DATA_FAILED:
       return "Retrieve data failed";
+    case error_code::SEQUENCE_EXISTS_FAILED:
+      return "Sequence exists failed";
     case error_code::RESET_FAILED:
       return "Reset failed";
     case error_code::OPEN_ERROR:

test/backends/SequenceFixture.cpp

@@ -10,8 +10,7 @@
 
 namespace matador::test {
 SequenceFixture::SequenceFixture()
-: db(connection::dns)
+: db(connection::dns) {
-, repo(db.dialect().default_schema_name()) {
     REQUIRE(db.open());
 }
 
@@ -20,7 +19,6 @@ SequenceFixture::~SequenceFixture() {
     drop_sequence_if_exists(sequences_to_drop.top());
     sequences_to_drop.pop();
   }
-  REQUIRE(repo.drop(db));
   REQUIRE(db.close());
 }
 
@@ -37,5 +35,16 @@ void SequenceFixture::check_sequence_not_exists(const std::string& sequence_name
 }
 
 void SequenceFixture::drop_sequence_if_exists(const std::string& sequence_name) const {
+  const auto result = db.sequence_exists(sequence_name).and_then([&sequence_name, this](const bool exists) {
+    if (exists) {
+      auto res = query::query::drop()
+        .sequence(sequence_name)
+        .execute(db);
+      REQUIRE(res);
+      this->check_sequence_not_exists(sequence_name);
+    }
+    return utils::ok(true);
+  });
+  REQUIRE(result);
 }
 }

test/backends/SequenceFixture.hpp

@@ -1,7 +1,6 @@
 #ifndef MATADOR_SEQUENCE_FIXTURE_HPP
 #define MATADOR_SEQUENCE_FIXTURE_HPP
 
-
 #include "matador/query/schema.hpp"
 
 #include "matador/sql/connection.hpp"
@@ -20,7 +19,6 @@ public:
 protected:
     sql::connection db;
     std::stack <std::string> sequences_to_drop;
-    query::schema repo;
 
 private:
     void drop_sequence_if_exists(const std::string &sequence_name) const;

test/backends/SequenceTest.cpp

@@ -7,7 +7,7 @@
 using namespace matador::query;
 using namespace matador::test;
 
-TEST_CASE_METHOD(SequenceFixture, "", "[sequence]") {
+TEST_CASE_METHOD(SequenceFixture, "test create and drop sequence", "[sequence][create][drop]") {
   auto result = query::create()
     .sequence("person_seq")
     .execute(db);
@@ -22,6 +22,13 @@ TEST_CASE_METHOD(SequenceFixture, "", "[sequence]") {
   REQUIRE(next_id.is_ok());
   REQUIRE(*next_id == 1);
 
+  auto curr_id = query::select()
+    .currval("person_seq")
+    .fetch_value<uint32_t>(db);
+
+  REQUIRE(curr_id.is_ok());
+  REQUIRE(*curr_id == 1);
+
   result = query::drop()
     .sequence("person_seq")
     .execute(db);