sql中的条件与新创建的字段 [英] where condition in sql with newly created field

问题描述

我有以下查询，为什么我的where子句不能工作?该值确实存在于表中.

I have the following query, why cant I get my where clause to work? The value does exist in the table.

 Select B.*, B.[RF attribute1] & "|" & B.[RF attribute2] & "|" & B.[RF attribute3] & "|" & B.[RF attribute4] as new_field 
FROM [Black$] as B 
where new_field = "Stack|over||flow"

错误消息是No value given for one or more required paramters

修改，实际数据:

+---------------+---------------+---------------+---------------+
| RF attribute1 | RF attribute2 | RF attribute3 | RF attribute4 |
+---------------+---------------+---------------+---------------+
| BONDZERO      | AUD           |               | MID           |
| BONDZERO      | AUD           |               | MID           |
| SWAPZERO      | AUD           |               | MID           |
| SWAPZERO      | AUD           |               | MID           |

这将创建一个新字段，如下所示:

which will create a new field like so:

+-------------------+
|     new_field     |
+-------------------+
| BONDZERO|AUD||MID |
| BONDZERO|AUD||MID |
| SWAPZERO|AUD||MID |
| SWAPZERO|AUD||MID |
+-------------------+

现在我正在尝试使用where子句BONDZERO|AUD||MID，因此它仅返回前2行.

Now i am trying to use the where clause BONDZERO|AUD||MID so it only returns the first 2 rows.

推荐答案

使用子查询:

select b.*
from (Select B.*, B.[RF attribute1] & "|" & B.[RF attribute2] & "|" & B.[RF attribute3] & "|" & B.[RF attribute4] as new_field 
      from [Black$] as B 
     ) as b
where new_field = "Stack|over||flow";

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