Discussion: where column
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Vieux 24/08/2007, 06h16   #2
Reinhardt Christiansen
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----- Original Message -----
From: "Olav Mørkrid" <olav.morkrid@gmail.com>
To: <mysql@lists.mysql.com>
Sent: Friday, August 24, 2007 1:07 AM
Subject: where column


> hello
>
> does anyone know what is returned when you do a where column without
> further parameters?
>
> SELECT * FROM TABLE WHERE COLUMN;
>
> for integer columns it seems to return non-zero columns, but for other
> types of columns the results seemed unpredictable.
>

In my opinion, the statement should not execute at all since it isn't
syntactically correct. In the dialects of SQL I have used - and I've been
using SQL for a lot of years - simply saying "WHERE hiredate" (or whatever
column name you want) is an incomplete statement since the column name must
be followed by some kind of operator, such as =, <, >, LIKE, or whatever.

Despite that, I am not up-to-date on MySQL and they may support an extension
that lets you write SQL like that; in that case, the MySQL manual for your
version should make it clear what happens if you write that.

But I still think it should not execute at all. The WHERE clause is a filter
to prevent rows that don't satisfy the condition from appearing in your
result set; "WHERE columnname" is not a complete condition in my opinion so
it simply should execute.

--
Rhino

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