backend tests progress

src/sql/record.cpp

@@ -1,5 +1,6 @@
 #include "matador/sql/record.hpp"
 
+#include <algorithm>
 #include <stdexcept>
 
 namespace matador::sql {
@@ -133,6 +134,13 @@ void record::clear()
   columns_by_name_.clear();
 }
 
+bool record::unknown() const
+{
+  return std::all_of(std::begin(columns_), std::end(columns_), [](const auto &col) {
+    return col.type() == data_type_t::type_unknown;
+  });
+}
+
 void record::init()
 {
   size_t index{0};