Add SteanwarUser.getOnlineTime

SpigotCore_Main/src/de/steamwar/sql/SteamwarUser.java

@@ -88,6 +88,17 @@ public class SteamwarUser {
 		return bedrock;
 	}
 
+	public double getOnlineTime() {
+		ResultSet set = SQL.select("SELECT SUM(UNIX_TIMESTAMP(EndTime) - UNIX_TIMESTAMP(StartTime)) as Playtime FROM Session WHERE UserID = ?", id);
+		try {
+			set.next();
+			return set.getBigDecimal("Playtime").doubleValue();
+		} catch (SQLException throwables) {
+			throwables.printStackTrace();
+		}
+		return 0;
+	}
+
 	private static SteamwarUser fromDB(String statement, Object identifier){
 		ResultSet rs = SQL.select(statement, identifier);
 		try {