I have a mysql database and want to have one column display images.
I created a folder called 'images' for my jpg's.

Ran this code:
[code ]
update gpstable set pic = '<img src="/images/maestro4210.jpg" alt="Maestro 4210" />' WHERE id = '3';
[/code ]

Now the table displays a small broken-link picture.

Is there something wrong with my sql statement?

Try:

UPDATE `gpstable` SET `pic` = '<img src="/images/maestro4210.jpg" alt="Maestro 4210" />' WHERE `id` =3 LIMIT 1

SQL can be a bit iffy about capitalisation (it seems to prefer it)

Tried it - same result.
Curious - What is LIMIT 1?

Try it without the relative path (ie http://mysite.com/images/image1.jpg).

Rather than storing the path to an image, you can also store the image itself using the blob data type.
http://www.phpriot.com/articles/images-in-mysql

Escape the inputs from quotes etc. first, for example with the mysql_real_escape() function, before you put them in an SQL query.

Courious too :P - And why are you storing a complete html tag? Why not just save the path and put it in an <img> tag your self when you need it? As in

UPDATE gpstable SET pic='/images/picture.jpg' WHERE id='3' LIMIT 1

The 'LIMIT 1' clause makes sure only 1 row is affected. So in case something goes bad, for exmaple if some jackass manages to make an SQL injection attack or similar and tries to screw thing up for you, it will still only affect one row instead of, lets say the whole table.

Tried:
UPDATE gpstable SET pic='/images/picture.jpg' WHERE id='3' LIMIT 1

Displays:
/images/maestro4210.jpg
instead of the actual picture.

Also tried the full path and found out that my database needs reconfiguring for more characters.

Of course it only displays the path :P
I meant for you to put the path in an <img> tag your self, like this

PHP Code:

echo '<img src="' . $path . '">'; // Where $path is the 'pic' value from the database