Question PLEASE ANSWER :) (2 Viewers)

[KAty]

hey can someone please explain me to me the different keys i.e. foreign keys, primary, secondary etc.
i have looked in excel and heinemann but they are not very good explanations and my IPT teacher is the worst!!

 

[fatmuscle]

Database notes from Uni

 

[Huy]

Originally posted by KAty
i have looked in excel and heinemann but they are not very good explanations

I don't know how else to say it... Heinemann explains things very well, and if used in conjunction with Excel, and it still doesn't make any sense, that's a cause for concern. (which is why you came here, I know).

Keys - fields used to sort/retrieve information
Each key holds a unique item, which applies to one record.
So you could say that a key is a "field entry"

Types of keys:

* single
* composite
* primary
* secondary

Single key - must contain data that is unique

Composite key - created by joining 2 or more fields together.
You will only need a composite key if you have a field which cannot be guaranteed to be unique, so you combine other fields together (to form a composite key), which is definately unique.

For example "Kat.BOS.2003.IPT"

Primary key - must contain a data item/value, they cant be empty or null.

Secondary key - field containing useful items that can be used in searches

That's really all there is to know about them.
I don't know what else to say, or any other way to simplify it for you.

 

[rx72c]

Oh yeh did Huy explain well enough, i think thats a pretty good explanation of keys, but if you want i have some notes that explain it slightly different maybe that might click in your mind.
Ill call Huy, Heinmann Instead from now on.

 

[rx72c]

Woops my english is shocking but im sure you all undertand me. If you dont please say so, ill explain my self

 

[Huy]

Originally posted by rx72c
Ill call Huy, Heinmann Instead from now on.

I laughed at this
Can you call me "G.K. Powers" instead? LOL!!!

I'm not serious there by the way,

 

[rx72c]

Huy, you know you should be a moderator of this Forum, the IPT section i mean, youve really put on a lot of posts.have you been offered that position.

 

[Azn fairies]

yes he has..but his too modest . and rejected it ...

or maybe his too good for it (joking)

 

[Huy]

Originally posted by rx72c
Huy, you know you should be a moderator of this Forum, the IPT section i mean, youve really put on a lot of posts.have you been offered that position.

Thanks.

Yes, I have been offered the position for "IPT", and as well as "IT Stuff", but I declined the preliminary round. So Winston has taken my place in IT Stuff and is also currently IT (VET) moderator.

The offer is still available for me as IT Stuff (joint, or otherwise) and IPT, but I am not considering it until after the HSC, or not at all, I'm afraid.

It's just who I am and "how I work"

 

[rx72c]

Oh ok i see, probably dont have enough time. I dont know the requirements of being a moderator, they may be difficult. So yeh just wanted to know if they offered you because you did damn well deserve it.

 

[fatmuscle]

as if Huy doesn't have enough time. Look at his post count.

 

[Huy]

Originally posted by fatmuscle
as if Huy doesn't have enough time. Look at his post count.

This is partly true, to an extent. I've got time now, since I haven't even started studying for any of my 6 subjects. I'll be doing a lot of that in the holidays, and also during STUVAC, so I won't be here as often. Just letting people know early

 

[rx72c]

Ill probably never come to this forum again after my HSC is finished, it will be filled with all these newbies who are all excited about this HSC, then couple of weeks later they will realise how damn boring the HSC is.

 

[Huy]

Originally posted by rx72c
Ill probably never come to this forum again after my HSC is finished

I feel the same way, which is disappointing.
I wouldn't have the time to browse BOS, given 1st year university and all that goes on when you're 18.

 

[Harish]

Nah. call Huy Gregory Juniour

 

[Huy]

Originally posted by Azn fairies
yes he has..but his too modest . and rejected it ...

or maybe his too good for it (joking)

LOL I never saw this post...

A) Too modest? Possibly
B) Rejected it? Yes, I have 'thrown it back', but it is still an option.
C) Too good for it? *whistles* we know the answer to that one

Hahaha I'm not serious about the last one, I'm not 'too good' for anything. (See A )

 

[fatmuscle]

Originally posted by Huy
I wouldn't have the time to browse BOS, given 1st year university and all that goes on when you're 18.

look at me...

 

[Huy]

Originally posted by fatmuscle
look at me...

That reminds me of Kath and Kim,
"Look at moi Kimmy, look at moi"

You're right fatmuscle, it's not impossible to juggle forum moderator and posting with University life (and that goes for tactic/Laz and the gang), but I'm not making any guarantees, that's all

 

[...]

look whos back!!

 

[Huy]

Originally posted by ...
look whos back!!

Who me?

I'm not here for long "..."
Maybe a day, or two.

But from Monday, I'll have to go.

I'm also online because Smallville (Season 3, Episode 1, Exile) has aired in the states, so I need to ... shall we say, "preview" the episode?