我想从我的2个表格中选择多个列：
表货币
select * from Currency order by timestamp desc limit 30;
+----------+----------+--------+--------+---------------------+
| platID | currency | buy | sell | timestamp |
+----------+----------+--------+--------+---------------------+
| 2 | EUR | 4.1281 | 4.1561 | 2015-08-01 13:47:01 |
| 1 | USD | 3.7589 | 3.7889 | 2015-08-01 13:47:01 |
| 2 | USD | 3.7563 | 3.7843 | 2015-08-01 13:47:01 |
| 2 | GBP | 5.8732 | 5.9122 | 2015-08-01 13:47:01 |
| 1 | EUR | 4.1265 | 4.1565 | 2015-08-01 13:47:01 |
| 1 | GBP | 5.8734 | 5.9134 | 2015-08-01 13:47:01 |
| 2 | CHF | 3.8904 | 3.9249 | 2015-08-01 13:47:01 |
| 1 | CHF | 3.8928 | 3.9328 | 2015-08-01 13:47:01 |
| 1 | USD | 3.7589 | 3.7889 | 2015-08-01 13:46:02 |
| 1 | GBP | 5.8734 | 5.9134 | 2015-08-01 13:46:02 |
| 1 | EUR | 4.1265 | 4.1565 | 2015-08-01 13:46:02 |
| 1 | CHF | 3.8928 | 3.9328 | 2015-08-01 13:46:02 |
| 2 | USD | 3.7563 | 3.7843 | 2015-08-01 13:46:01 |
| 2 | EUR | 4.1281 | 4.1561 | 2015-08-01 13:46:01 |
| 2 | CHF | 3.8904 | 3.9249 | 2015-08-01 13:46:01 |
| 2 | GBP | 5.8732 | 5.9122 | 2015-08-01 13:46:01 |
+----------+----------+--------+--------+---------------------+
表格平台
select * from Platforms
+----------+----------------------+
| platID | domain |
+----------+----------------------+
| 0 | domain1 |
| 1 | domain2 |
| 2 | domain3 |
| 3 | domain4 |
| 4 | domain5 |
| 5 | domain6 |
+----------+----------------------+
我希望从表平台获取所请求货币或所有货币的每个域的以下输出
+-----------+-----------------+------------------+-----------------+------------------+
| timestamp | domain1 USD buy | domain1 USD sell | domain2 USD buy | domain2 USD sell |
+-----------+-----------------+------------------+-----------------+------------------+
| 13:44 | 3.7589 | 3.7889 | 3.7589 | 3.7889 |
+-----------+-----------------+------------------+-----------------+------------------+