What is the Value of Blank Table Cell???

[jjdave]

I have two tables as shown below:

Table 1: Actor.............................Table 2: Movie
Field:...ID.....Last......First..............Field:...ID.....Last......Movie
...........1.....Willis......Bruce.......................1.....Willis......Die Hard
...........2 ....Cruze....Tom..........................2.....Cruze.....MI-III
...........3.....Pitt.......Brad
...........4 ....Depp.....Johnny

Then I JOIN the tables with Query which works fine, following is the result:
Field:...Last......First........Movie
..........Willis......Bruce......Die Hard
..........Cruze....Tom.........Cruze MI-III
..........Pitt.......Brad
..........Depp.....Johnny

MY QUESTION: What is stored in the Movie column for Brad Pitt and Johnny Depp? Is that value NULL? or is that value EMPTY? What is it?
Because I want to create IF clause as follows:
IF ($Movie = String)
{ Do this }
else
{ Do that }

I appriciate this very much. Hope this makes sense.

[wonshikee]

the default value of a column is based on what you set it to be, and what data type it is.
most like

if ($movie == '') for checking if its empty should work based on the assumption that your column type is varchar.

[jjdave]

Well, in table Movie, I have two other fields:
1. ID which is INT data type
2. Movie which is VARCHAR data type

So what would be the value?

[wonshikee]

varchar by default is empty string ""

and int by default is 0

[catweasel]

In the example you've given it would be null.. you can check for it like this -

if (!empty($movie)) echo $movie; 

I think in your movie table, instead of using the actor's last name use their id.. call it actor_id

[jjdave]

Thank You wonshikee & catweasel

What I thought was right, about VARCHAR as "" and INT as 0. I also checked the !empty for the NULL.

I think I might have problem with other code that are mixed in to the problem I just mentioned.

Once again, Thank you and I need to check my algorithm and recheck my code.

[jjdave]

Thank You wonshikee & catweasel
Solution you provided was correct: VARCHAR as "" and INT as 0 and !empty as NULL. They all work fine.

I found the problem in my sentex structure on Rollover link. I forgot to put Single Quote in A HREF. I fixed it as below and it works fine now.

echo "<A HREF='movie_data.php?$URLvar3'><b>$Last</b></A>"; 

Once again, Thank you.
jjdave...