Question

我的MySQL查询有问题。我的数据看起来像这样：

transaction_type | currency_from | currency_to |
------------------------------------------------
swap             | USD           | IDR         |
swap             | IDR           | USD         |
forward          | GBP           | USD         |
forward          | USD           | GBP         |
forward          | JPY           | EUR         |
forward          | EUR           | JPY         |
spot             | USD           | EUR         |
spot             | EUR           | USD         |

是否可以让输出看起来像这样：

transaction_type | currency_from | currency_to |
------------------------------------------------
swap             | USD           | IDR         |
forward          | GBP           | USD         |
forward          | JPY           | EUR         |
spot             | USD           | EUR         |

如上所述，每笔交易都会有逆转交易，掉期美元兑换IDR，也会有掉期IDR-USD远期英镑兑美元也会有远期美元兑英镑，所以做现货。我尝试了很多方法，但仍然没有成功。有人可以帮忙吗？在此之前谢谢..

Answer 1

您可以执行以下操作

SELECT t1.*
FROM tblTransaction AS t1 INNER JOIN tblTransaction AS t2
ON (
    t1.transaction_type = t2.transaction_type AND 
    t1.currency_from = t2.currency_to AND
    t1.currency_to = t2.currency_from AND
    t1.currency_from > t2.currency_from
)

MySQL查询反转数据

1 个答案: