query/include/matador/orm/session_query_builder.hpp

297 lines
11 KiB
C++

#ifndef QUERY_ENTITY_QUERY_BUILDER_HPP
#define QUERY_ENTITY_QUERY_BUILDER_HPP
#include "matador/orm/query_builder_exception.hpp"
#include "matador/query/criteria.hpp"
#include "matador/query/query.hpp"
#include "matador/sql/executor.hpp"
#include "matador/sql/statement.hpp"
#include "matador/object/join_columns_collector.hpp"
#include "matador/object/repository.hpp"
#include "matador/query/criteria/criteria_visitor.hpp"
#include "matador/utils/primary_key_attribute.hpp"
#include "matador/utils/result.hpp"
#include "matador/utils/value.hpp"
#include <stack>
#include <unordered_map>
namespace matador::orm {
struct entity_query_data {
std::shared_ptr<sql::table> root_table;
std::string pk_column_name{};
std::vector<sql::column> columns{};
std::unordered_map<std::string, sql::statement> lazy_loading_statements{};
std::vector<query::join_data> joins{};
query::criteria_ptr where_clause;
};
class criteria_transformer final : public query::criteria_visitor {
public:
criteria_transformer(const object::repository &repo, const std::unordered_map<std::string, std::shared_ptr<sql::table>>& tables_by_name);
void visit( const query::between_criteria& node ) override;
void visit( const query::binary_criteria& node ) override;
void visit( const query::binary_column_criteria& node ) override;
void visit( const query::collection_criteria& node ) override;
void visit( const query::collection_query_criteria& node ) override;
void visit( const query::like_criteria& node ) override;
void visit( const query::logical_criteria& node ) override;
void visit( const query::not_criteria& node ) override;
private:
void update_criteria_column(const query::abstract_column_criteria& node) const;
private:
const object::repository &repo_;
const std::unordered_map<std::string, std::shared_ptr<sql::table>>& tables_by_name_;
};
class session_query_builder final {
public:
session_query_builder(const object::repository &scm, sql::executor &exec)
: schema_(scm)
, executor_(exec){}
template<class EntityType>
utils::result<entity_query_data, query_build_error> build(query::criteria_ptr clause = {}) {
const auto info = schema_.info<EntityType>();
if (!info) {
return utils::failure(query_build_error::UnknownType);
}
table_info_stack_.push({info.value(), std::make_shared<sql::table>(info.value().get().name(), build_alias('t', ++table_index))});
entity_query_data_ = { table_info_stack_.top().table };
processed_tables_.insert({info->get().name(), entity_query_data_.root_table});
try {
access::process(*this, info->get().prototype());
if (clause) {
criteria_transformer transformer{schema_, processed_tables_};
clause->accept(transformer);
entity_query_data_.where_clause = std::move(clause);
}
return {utils::ok(std::move(entity_query_data_))};
} catch (const query_builder_exception &ex) {
return {utils::failure(ex.error_type())};
} catch (...) {
return {utils::failure(query_build_error::UnexpectedError)};
}
}
template < class V >
void on_primary_key(const char *id, V &, const utils::primary_key_attribute& /*attr*/ = utils::default_pk_attributes) {
push(id);
if (!is_root_entity()) {
return;
}
entity_query_data_.pk_column_name = id;
}
void on_revision(const char *id, uint64_t &/*rev*/);
template<typename Type>
void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes)
{
push(id);
}
template<class Pointer>
void on_belongs_to(const char *id, Pointer &obj, const utils::foreign_attributes &attr)
{
on_foreign_object(id, obj, attr);
}
template<class Pointer>
void on_has_one(const char *id, Pointer &obj, const utils::foreign_attributes &attr)
{
on_foreign_object(id, obj, attr);
}
template<class ContainerType>
void on_has_many(const char * /*id*/, ContainerType &, const char *join_column, const utils::foreign_attributes &attr) {
if (attr.fetch() == utils::fetch_type::EAGER) {
const auto info = schema_.info<typename ContainerType::value_type::value_type>();
if (!info) {
throw query_builder_exception{query_build_error::UnknownType};
}
auto next = processed_tables_.find(info->get().name());
if (next != processed_tables_.end()) {
return;
}
table_info_stack_.push({info.value(), std::make_shared<sql::table>(info->get().name(), build_alias('t', ++table_index))});
next = processed_tables_.insert({info->get().name(), table_info_stack_.top().table}).first;
typename ContainerType::value_type::value_type obj;
access::process(*this , obj);
table_info_stack_.pop();
auto pk = info->get().definition().primary_key();
if (!pk) {
throw query_builder_exception{query_build_error::MissingPrimaryKey};
}
append_join(
sql::column{table_info_stack_.top().table, table_info_stack_.top().info.get().definition().primary_key()->name()},
sql::column{next->second, join_column}
);
}
}
template<class ContainerType>
void on_has_many_to_many(const char *id, ContainerType &/*cont*/, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr) {
if (attr.fetch() != utils::fetch_type::EAGER) {
return;
}
const auto info = schema_.info<typename ContainerType::value_type::value_type>();
if (!info) {
throw query_builder_exception{query_build_error::UnknownType};
}
auto next = processed_tables_.find(info->get().name());
if (next != processed_tables_.end()) {
return;
}
auto relation = processed_tables_.find(id);
if (relation == processed_tables_.end()) {
relation = processed_tables_.insert({id, std::make_shared<sql::table>(id, build_alias('t', ++table_index))}).first;
}
table_info_stack_.push({info.value(), std::make_shared<sql::table>(info->get().name(), build_alias('t', ++table_index))});
next = processed_tables_.insert({info->get().name(), table_info_stack_.top().table}).first;
typename ContainerType::value_type::value_type obj;
access::process(*this , obj);
table_info_stack_.pop();
auto pk = info->get().definition().primary_key();
if (!pk) {
throw query_builder_exception{query_build_error::MissingPrimaryKey};
}
append_join(
sql::column{table_info_stack_.top().table, table_info_stack_.top().info.get().definition().primary_key()->name()},
sql::column{relation->second, join_column}
);
append_join(
sql::column{relation->second, inverse_join_column},
sql::column{next->second, pk->name()}
);
}
template<class ContainerType>
void on_has_many_to_many(const char *id, ContainerType &/*cont*/, const utils::foreign_attributes &attr) {
if (attr.fetch() != utils::fetch_type::EAGER) {
return;
}
const auto info = schema_.info<typename ContainerType::value_type::value_type>();
if (!info) {
throw query_builder_exception{query_build_error::UnknownType};
}
auto next = processed_tables_.find(info->get().name());
if (next != processed_tables_.end()) {
return;
}
auto relation = processed_tables_.find(id);
if (relation == processed_tables_.end()) {
relation = processed_tables_.insert({id, std::make_shared<sql::table>(id, build_alias('t', ++table_index))}).first;
}
table_info_stack_.push({info.value(), std::make_shared<sql::table>(info->get().name(), build_alias('t', ++table_index))});
next = processed_tables_.insert({info->get().name(), table_info_stack_.top().table}).first;
typename ContainerType::value_type::value_type obj;
access::process(*this , obj);
table_info_stack_.pop();
auto pk = info->get().definition().primary_key();
if (!pk) {
throw query_builder_exception{query_build_error::MissingPrimaryKey};
}
const auto join_columns = join_columns_collector_.collect<typename ContainerType::value_type::value_type>();
append_join(
sql::column{table_info_stack_.top().table, table_info_stack_.top().info.get().definition().primary_key()->name()},
sql::column{relation->second, join_columns.inverse_join_column}
);
append_join(
sql::column{relation->second, join_columns.join_column},
sql::column{next->second, pk->name()}
);
}
private:
template<class Pointer>
void on_foreign_object(const char *id, Pointer &, const utils::foreign_attributes &attr);
void push(const std::string &column_name);
static std::string build_alias(char prefix, unsigned int count);
[[nodiscard]] bool is_root_entity() const;
void append_join(const sql::column &left, const sql::column &right);
private:
struct table_info {
std::reference_wrapper<const object::basic_object_info> info;
std::shared_ptr<sql::table> table;
};
std::stack<table_info> table_info_stack_{};
std::unordered_map<std::string, std::shared_ptr<sql::table>> processed_tables_{};
const object::repository &schema_;
entity_query_data entity_query_data_{};
unsigned int column_index{0};
unsigned int table_index{0};
object::join_columns_collector join_columns_collector_{};
sql::executor &executor_;
};
template<class Pointer>
void session_query_builder::on_foreign_object(const char *id, Pointer &, const utils::foreign_attributes &attr) {
const auto info = schema_.info<typename Pointer::value_type>();
if (!info) {
throw query_builder_exception{query_build_error::UnknownType};
}
auto pk = info->get().definition().primary_key();
if (!pk) {
throw query_builder_exception{query_build_error::MissingPrimaryKey};
}
const auto foreign_table = std::make_shared<sql::table>(info->get().name(), build_alias('t', ++table_index));
if (attr.fetch() == utils::fetch_type::EAGER) {
auto next = processed_tables_.find(info->get().name());
if (next != processed_tables_.end()) {
return;
}
table_info_stack_.push({info.value(), foreign_table});
next = processed_tables_.insert({info->get().name(), table_info_stack_.top().table}).first;
typename Pointer::value_type obj;
access::process(*this, obj);
table_info_stack_.pop();
append_join(
sql::column{table_info_stack_.top().table, id},
sql::column{next->second, pk->name()}
);
} else {
push(id);
using namespace matador::utils;
using namespace matador::query;
// create select query
auto result = matador::query::query::select(sql::column_generator::generate<typename Pointer::value_type>(schema_, true))
.from(*foreign_table)
.where(sql::column(foreign_table, pk->name(), "") == _)
.prepare(executor_);
if (!result) {
throw query_builder_exception(query_build_error::QueryError, result.release_error());
}
entity_query_data_.lazy_loading_statements.emplace(id, std::move(result.release()));
}
}
}
#endif //QUERY_ENTITY_QUERY_BUILDER_HPP