has many fetch with join

2025-02-19 14:51:42 +01:00
parent 784f6e768d
commit 8ab8274d93
19 changed files with 264 additions and 52 deletions
@@ -0,0 +1,78 @@
+#ifndef QUERY_RESULT_PK_RESOLVER_HPP
+#define QUERY_RESULT_PK_RESOLVER_HPP
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/field_attributes.hpp"
+#include "matador/utils/foreign_attributes.hpp"
+#include "matador/utils/identifier.hpp"
+
+#include "matador/sql/interface/query_result_reader.hpp"
+
+#include <stack>
+#include <string>
+
+namespace matador::sql::internal {
+
+class query_result_pk_resolver final {
+public:
+    explicit query_result_pk_resolver(query_result_reader &reader) : reader_(reader) {}
+
+    template<class Type>
+    utils::identifier discover(Type &obj) {
+        column_index_ = reader_.start_column_index();
+        pk_.clear();
+        access::process(*this, obj);
+
+        return pk_;
+    }
+
+    template<typename ValueType>
+    void on_primary_key(const char *id, ValueType &/*value*/, std::enable_if_t<std::is_integral_v<ValueType> && !std::is_same_v<bool, ValueType>>* = nullptr) {
+        if (!type_stack_.empty()) {
+            return;
+        }
+        ValueType value;
+        utils::data_type_traits<ValueType>::read_value(reader_, id, column_index_++, value);
+        pk_ = value;
+    }
+    void on_primary_key(const char *id, std::string &value, size_t size);
+    void on_revision(const char * /*id*/, unsigned long long &/*rev*/) { ++column_index_; }
+
+    template < class Type >
+    void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) { ++column_index_; }
+    void on_attribute(const char *id, const utils::value &x, const utils::field_attributes &attr = utils::null_attributes);
+
+    template < class Pointer >
+    void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &attr) { on_foreign_key<typename Pointer::value_type>(attr.fetch() ); }
+    template < class Pointer >
+    void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &attr) { on_foreign_key<typename Pointer::value_type>(attr.fetch() ); }
+
+    template<class ContainerType>
+    void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
+    template<class ContainerType>
+    void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+    template<class ContainerType>
+    void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+    template<class Type>
+    void on_foreign_key(const utils::fetch_type fetch) {
+        if (fetch == utils::fetch_type::LAZY) {
+            ++column_index_;
+        } else {
+            const Type obj;
+            type_stack_.push(typeid(Type));
+            access::process(*this, obj);
+            type_stack_.pop();
+        }
+    }
+private:
+    size_t column_index_{};
+    utils::identifier pk_;
+    query_result_reader &reader_;
+    std::stack<std::type_index> type_stack_;
+};
+
+}
+
+#endif //QUERY_RESULT_PK_RESOLVER_HPP