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Images Table
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Nicholas Vettese
*nix forums beginner


Joined: 22 Jun 2006
Posts: 6

PostPosted: Thu Jul 20, 2006 2:19 pm    Post subject: Images Table Reply with quote
I am looking to create a database that holds the location of images on my server. I was wondering if anyone could help me understand if I am doing it correctly, and if I either need to add, change or remove something from the current table code.

img_id INT NOT NULL auto_increment PRIMARY KEY,
user_id INT NOT NULL,
location VARCHAR(255) NOT NULL,
imgtype VARCHAR(20) NOT NULL,
img_tag VARCHAR(50) NOT NULL,
img_rate VARCHAR(20) NOT NULL,
img_comments VARCHAR(50) NOT NULL,
KEY (img_id);

Thanks for any help.

nick
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Chris White
*nix forums beginner


Joined: 21 Apr 2006
Posts: 43

PostPosted: Thu Jul 20, 2006 3:03 pm    Post subject: Re: Images Table Reply with quote
On Thursday 20 July 2006 07:19 am, Nicholas Vettese wrote:
Quote:
img_id INT NOT NULL auto_increment PRIMARY KEY,
user_id INT NOT NULL,
location VARCHAR(255) NOT NULL,
imgtype VARCHAR(20) NOT NULL,
img_tag VARCHAR(50) NOT NULL,
img_rate VARCHAR(20) NOT NULL,

good

Quote:
img_comments VARCHAR(50) NOT NULL,

bzzt, bad! Note here comment(s). You have a 1 to many relationship, as one
image can have many comments. What you need to do is have a separate table
for that:

CREATE TABLE image_comments (
id SERIAL PRIMARY KEY,
comment TEXT NOT NULL,
image_id INT NOT NULL,
CONSTRAINT `foreign_images_comments`
FOREIGN KEY `foreign_images_comments` (`image_id`)
REFERENCES `[image-table]` `img_id`
ON DELETE CASCADE
);

then:

SELECT comment FROM image_comments WHERE image_id = [image_id_here];

Why? Think about how you'd need to add comments. You'd have 2 choices:

1) Shove all the comments in one column (get ready for a HUGE table)
2) Create a separate image row for each comment (lots of duplicate data, bad!)

Quote:
KEY (img_id);

Not needed, you already declared it a key above (PRIMARY KEY)

Quote:
Thanks for any help.

nick

--
Chris White
PHP Programmer/DBoooooo
Interfuel

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