1 files changed, 38 insertions, 0 deletions
diff --git a/src/database/index.hpp b/src/database/index.hpp
new file mode 100644
index 0000000..30766ab
--- /dev/null
+++ b/src/database/index.hpp
@@ -0,0 +1,38 @@
+#pragma once
+
+#include <database/engine.hpp>
+
+#include <string>
+#include <tuple>
+
+namespace
+{
+template <std::size_t N=0, typename... T>
+typename std::enable_if<N == sizeof...(T), void>::type
+add_column_name(std::string&)
+{ }
+
+template <std::size_t N=0, typename... T>
+typename std::enable_if<N < sizeof...(T), void>::type
+add_column_name(std::string& out)
+{
+  using ColumnType = typename std::remove_reference<decltype(std::get<N>(std::declval<std::tuple<T...>>()))>::type;
+  out += ColumnType::name;
+  if (N != sizeof...(T) - 1)
+    out += ",";
+  add_column_name<N+1, T...>(out);
+}
+}
+
+template <typename... Columns>
+void create_index(DatabaseEngine& db, const std::string& name, const std::string& table)
+{
+  std::string query{"CREATE INDEX IF NOT EXISTS "};
+  query += name + " ON " + table + "(";
+  add_column_name<0, Columns...>(query);
+  query += ")";
+
+  auto result = db.raw_exec(query);
+  if (std::get<0>(result) == false)
+    log_error("Error executing query: ", std::get<1>(result));
+}