mysql, what exactly that code "constraint" does?
<p>I know what foreign key is. However what is the difference between adding the </p>

<p>CONSTRAINT <code>test1</code>    ??</p>

<p>AND</p>

<p>without it?</p>

<p>The code "CONSTRAINT" what exactly does it do, since you can add foreign key without that code anyway.</p>

<p>Thanks,
Ed</p>