Need advice on building OHLC or candlestick charts

In theory, to build a candle chart, we need :

1. get trade data - for example

+---------+---------------------+-----------+------------+-------------+-----------+
| Deal_ID | DATE | Deal_Type | Amount_USD| Amount_Coin | Price_USD |
+---------+---------------------+-----------+------------+-------------+-----------+
| 1 | 2017-12-01 07:00:00 | sell | 2000 | 2 | 1000 |
| 2 | 2017-12-01 07:00:55 | buy | 2000 | 2 | 1000 |
| 3 | 2017-12-01 07:01:00 | sell | 6000 | 5 | 1200 |
| 4 | 2017-12-01 07:01:20 | buy | 6000 | 5 | 1200 |
| 5 | 2017-12-01 07:02:00 | buy | 9000 | 10 | 900 |
| 6 | 2017-12-01 07:02:10 | sell | 9000 | 10 | 900 |
| 7 | 2017-12-01 07:03:00 | sell | 6600 | 6 | 1100 |
| 8 | 2017-12-01 07:03:43 | buy | 6600 | 6 | 1100 |
| 9 | 2017-12-01 07:04:00 | sell | 3900 | 3 | 1300 |
| 10 | 2017-12-01 07:04:22 | buy | 3900 | 3 | 1300 |
| 11 | 2017-12-01 07:05:00 | sell | 2500 | 2 | 1250 |
| 12 | 2017-12-01 07:05:11 | buy | 2500 | 2 | 1250 |
| 13 | 2017-12-01 07:06:00 | sell | 1400 | 1 | 1400 |
| 14 | 2017-12-01 07:06:00 | buy | 1400 | 1 | 1400 |
| 15 | 2017-12-01 07:07:00 | buy | 4050 | 3 | 1350 |
| 16 | 2017-12-01 07:07:03 | sell | 4050 | 3 | 1350 |
| 17 | 2017-12-01 07:08:00 | sell | 4800 | 4 | 1200 |
| 18 | 2017-12-01 07:08:00 | buy | 4800 | 4 | 1200 |
| 19 | 2017-12-01 07:09:00 | sell | 3300 | 3 | 1100 |
| 20 | 2017-12-01 07:09:00 | buy | 3300 | 3 | 1100 |
| 21 | 2017-12-01 07:10:00 | sell | 5500 | 5 | 1100 |
| 22 | 2017-12-01 07:10:00 | buy | 5500 | 5 | 1100 |
| 23 | 2017-12-01 07:11:00 | buy | 7800 | 6 | 1300 |
| 24 | 2017-12-01 07:11:00 | sell | 7800 | 6 | 1300 |
| 25 | 2017-12-01 07:12:00 | buy | 6250 | 5 | 1250 |
| 26 | 2017-12-01 07:12:05 | sell | 6250 | 5 | 1250 |
+---------+---------------------+-----------+------------+-------------+-----------+

2. merge buy / sell deal into one transaction
+---------------------+-------------+-----------+
| date | amount_coin | price_usd |
+---------------------+-------------+-----------+
| 2017-12-01 07:00:00 | 2 | 1000 |
| 2017-12-01 07:01:00 | 5 | 1200 |
| 2017-12-01 07:02:00 | 10 | 900 |
| 2017-12-01 07:03:00 | 6 | 1100 |
| 2017-12-01 07:04:00 | 3 | 1300 |
| 2017-12-01 07:05:00 | 2 | 1250 |
| 2017-12-01 07:06:00 | 1 | 1400 |
| 2017-12-01 07:07:00 | 3 | 1350 |
| 2017-12-01 07:08:00 | 4 | 1200 |
| 2017-12-01 07:09:00 | 3 | 1100 |
| 2017-12-01 07:10:00 | 5 | 1100 |
| 2017-12-01 07:11:00 | 6 | 1300 |
| 2017-12-01 07:12:00 | 5 | 1250 |
+---------------------+-------------+-----------+

3. we obtain OHLC data for the interval of 180 seconds
+---------------------+------------+--------+------+------+------+-------+
| date | timestamp | volume | open | high | low | close |
+---------------------+------------+--------+------+------+------+-------+
| 2017-12-01 07:00:00 | 1512104400 | 26 | 1000 | 1300 | 900 | 1300 |
| 2017-12-01 07:05:00 | 1512104700 | 13 | 1250 | 1400 | 1100 | 1100 |
| 2017-12-01 07:10:00 | 1512105000 | 16 | 1100 | 1300 | 1100 | 1250 |
+---------------------+------------+--------+------+------+------+-------+

Everything is simple and clear.

but here we have REAL data from the poloniex exchange

TradeID   Date    Type   Price in BTC    Amount in NXT    Total in BTC

21387   2014-09-12 05:21:26   buy   0.00008943    1.27241180     0.00011379
21386   2014-09-12 05:21:26   buy   0.00008943    1.27241180   0.00011379
21385   2014-09-12 05:21:26   buy   0.00008943    238.28433663   0.02130976
21384   2014-09-12 05:21:26   buy   0.00008937    237.24284436   0.02120239
21383   2014-09-12 05:21:26   buy   0.00008937    222.40780368   0.01987658
21382   2014-09-12 05:20:50   sell   0.00008937    222.40777437   0.01987658
21380   2014-09-12 05:20:48   sell   0.00008937    15.87653295   0.00141888
21378   2014-09-12 05:20:45   sell   0.00008937    1409.86957705   0.12600004
21377   2014-09-12 05:20:45   buy   0.00008937    100.00000000   0.00893700
21376   2014-09-12 05:20:45   buy   0.00008936    2.00000000   0.00017872
21375   2014-09-12 05:20:45   buy   0.00008930    592.90881062   0.05294675
21374   2014-09-12 05:20:45   buy   0.00008900 34.45002070   0.00306605
21373   2014-09-12 05:20:45   buy   0.00008900    100.00000000   0.00890000
21372   2014-09-12 05:20:45   buy   0.00008900    71.28118327   0.00634402
21371   2014-09-12 05:20:45   buy   0.00008900    10.00000000   0.00089000
21370   2014-09-12 05:20:45   buy   0.00008850    468.00000000   0.04141800
21369   2014-09-12 05:20:45   buy   0.00008830    1000.00000000   0.08830000
21368   2014-09-12 05:20:45   buy   0.00008828    24.76164861   0.00218595
21367   2014-09-12 05:20:45   buy   0.00008796 2332.07990187   0.20512974
21366   2014-09-12 05:15:37   sell   0.00008809    247.29947465   0.02178461
21365   2014-09-12 04:49:13   sell   0.00008676    240.30574117   0.02084892
21364   2014-09-12 04:49:07   sell   0.00008813    77.09953900   0.00679478
21362   2014-09-12 04:48:59   sell   0.00008813    79.57717018   0.00701313
21360   2014-09-12 04:48:56   sell   0.00008813    3.28064742   0.00028912
21358   2014-09-12 04:48:54   sell   0.00008813   100.00000000   0.00881300
21356   2014-09-12 04:48:51   buy   0.00008813   240.04264340   0.02115495

The big question is - how to get data for candlestick charts from this mash ?