我有以下结果集,我正在尝试向下钻取
+----+---------+---------------+---------------------+----------------------+---------------+-----------+------------------+------------------+
| id | auth_id | trusts_number | buy_sell_actions_id | corporate_actions_id | fx_actions_id | submitted | created_at | updated_at |
+----+---------+---------------+---------------------+----------------------+---------------+-----------+------------------+------------------+
| 2 | 6 | N100723 | 2 | NULL | NULL | 0 | 08/05/2015 11:30 | 08/05/2015 15:32 |
| 5 | 6 | N100723 | NULL | NULL | 1 | 0 | 08/05/2015 15:10 | 08/05/2015 15:10 |
| 6 | 6 | N100723 | NULL | NULL | 2 | 1 | 08/05/2015 15:12 | 08/05/2015 15:41 |
+----+---------+---------------+---------------------+----------------------+---------------+-----------+------------------+------------------+
该结果集是通过查询生成的
SELECT * FROM actions WHERE auth_id = 6 AND trusts_number = 'N100723'
我也想摆脱fx_actions为NULL的任何字段,因此我将查询更改为
SELECT * FROM actions WHERE auth_id = 6 AND trusts_number = 'N100723' AND fx_actions_id != NULL
但是,这将返回一个空结果集。我以前从未在MySQL中使用过“负”查询参数,因此不确定是否应采用其他语法还是什么?
任何帮助将非常感激。
正常的比较运算符与不能很好地配合NULL
。双方Something = NULL
并Something != NULL
会返回“未知”,这导致的结果将被省略的行。使用特殊运算符IS NULL
,IS NOT NULL
而不是:
SELECT * FROM actions
WHERE auth_id = 6
AND trusts_number = 'N100723'
AND fx_actions_id IS NOT NULL
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我来说两句