Rewrite electricity-logger to use an sqlite3 database

include/solar/server/database/connection.hpp

@@ -0,0 +1,30 @@
+#pragma once
+#include <ctime>
+#include <sqlite3.h>
+#include <string>
+#include <util/date.hpp>
+
+namespace Database
+{
+    class Connection {
+    private:
+        sqlite3 * const connectionPtr;
+
+    public:
+        Connection(sqlite3 * const databaseConnectionPtr);
+
+        // Date should be in format yyyy-mm-dd
+        // Returns a JSON array
+        std::string GetEntireDay(Util::Date const & date);
+
+        // Dates should be in format yyyy-mm-dd
+        // Returns a JSON array
+        // startDate and endDate are inclusive
+        std::string GetSummarizedPerDayRecords(Util::Date const & startDate, Util::Date const & endDate);
+
+        // Dates should be in format yyyy-mm-dd
+        // Returns a JSON array
+        // startDate and endDate are inclusive
+        std::string GetSummarizedPerMonthRecords(Util::Date const & startDate, Util::Date const & endDate);
+    };
+}