Re: difference between UNION operator and OR in where clause

From: Mike <gongweigang_at_gmail.com>
Date: Tue, 10 Jul 2007 12:22:50 -0700
Message-ID: <1184095370.964674.41660@n60g2000hse.googlegroups.com>

On Jul 10, 2:06 pm, Lennart <erik.lennart.jons..._at_gmail.com> wrote:
> Mike wrote:
>
> > However, if using solution 2 with "select DISTINCT", it will output 3
> > titles instead.
>
> Yes, but I think you are missing the point. Focus on what Bob is trying
> to show you, and I think you will get the picture.
>
> /Lennart

Sorry. I still don't get it.

I know that my original solution 2 will fail in the case when either book or journal is empty.

But assuming that both book and journal are not empty, and solution 2 is using "Select DISTINCT ...", I think solution 2 and 1 can give the same results. Received on Tue Jul 10 2007 - 14:22:50 CDT