Merge branch 'master' into debian

1 files changed, 18 insertions, 2 deletions

diff --git a/src/database/column.hpp b/src/database/column.hpp
index 1f16bcf..837aa3f 100644
--- a/src/database/column.hpp
+++ b/src/database/column.hpp
@@ -9,14 +9,30 @@ struct Column
         value{default_value} {}
     Column():
         value{} {}
+    void clear()
+    {
+      this->value = {};
+    }
     using real_type = T;
     T value{};
 };
 
-struct Id: Column<std::size_t> {
+template <typename T>
+struct UnclearableColumn: public Column<T>
+{
+    using Column<T>::Column;
+    void clear()
+    { }
+};
+
+struct ForeignKey: Column<std::size_t> {
+    static constexpr auto name = "fk_";
+};
+
+struct Id: UnclearableColumn<std::size_t> {
     static constexpr std::size_t unset_value = static_cast<std::size_t>(-1);
     static constexpr auto name = "id_";
     static constexpr auto options = "PRIMARY KEY";
 
-    Id(): Column<std::size_t>(-1) {}
+    Id(): UnclearableColumn<std::size_t>(unset_value) {}
 };