Sql - Page 2

Anarasha · 01-25-2010, 02:28 AM

No, that's not what I meant o.o She's born and raised in Denmark, and she speaks the language just fine. What I meant was that the material we use in our classes has been translated to danish, and so the SQL terms are translated poorly as well.

Lochnar · 01-25-2010, 03:32 AM

Oh, ok. It still sucks but it's better then a teacher that doesn't speak the language.

Catch · 01-25-2010, 10:06 AM

Primary key should be unique. Most companies supply a unique code like EmployID.

Two tables:

Personal Info
EmployID - FirstName - LastName - PhoneNumber - Address

Employee Info
EmployID - JobTitle - Tenor - Wage

EmployID is a unique number, so when looking for information a person can run their name bring up a list, then pick the proper person based on what they know about them and access other tables related to the primary key (employee profile). You can also find out everything in the database about them by asking the employee id or swipe the id in a reader.

In addition, a person can search by job title and bring up everyone with that position to run stats for management tools. It is modular, divided between multiple tables so if a person wants to add SurName or delete address on Personal Info it is easy. Not as many delays having to completely restructure one giant table.

Lochnar · 01-25-2010, 03:54 PM

Insulate you PK by using values that have no meaning outside the context of the table.

Employee table
EmpID (PK), EmpNum (the company's employee number), LastName, FristName, etc...

Why? That employee number the company uses can change, it's happened to me. By adding an auto incremented number (EmpID) you insulate your data from the PK. Only supply secondary indexes (or indices if you like) to fields you know for fact will be used in searches. Reason being that managing each secondary index will take resources (on every insert and some updates) and you can always add another if the need to search by another field pops up.

Anarasha · 01-26-2010, 12:04 AM

You guys give me a headache...

Catch · 01-26-2010, 12:36 AM

You'll be okay Anarasha. Sometimes it makes more sense by practicing it on a computer. Those theories are often more confusing than helpful if you've never built a database.

Anarasha · 01-26-2010, 12:50 AM

Yeah, I just can't wait for the six weeks to be up so I can fail my exam and move on.
(Yup, they want us to learn the basics in six weeks.)

Lochnar · 01-27-2010, 04:49 AM

six weeks is enough for an introduction, at least it's not 16 weeks =)

Anarasha · 01-29-2010, 05:07 PM

Don't you fucking scare me by saying stuff like that!!!

(appearently, the Gnet mods added a filter against all caps messages. I suppose that's a good thing in most cases.)

Lochnar · 01-30-2010, 01:04 AM

Didn't I say I was a sadist?

Anarasha · 02-01-2010, 03:58 AM

We are now doing Java in BlueJ......... >_< Not a nice way to start your birthday.

Catch · 02-01-2010, 04:26 PM

Happy Birthday!!!

Anarasha · 02-03-2010, 05:16 AM

Thanks :D
(Okay, now they fixed the red X that used to be smileys, now they just disappear unless you remember to turn them off in the advanced view.)

Catch · 02-03-2010, 06:47 PM

Oh, I had been thinking about posting a college survival guide on my blog for awhile. Your immediate need moved it up in priority.

http://quidprogrow.blogspot.com/2010...hort-term.html

This one, I believe is especially according to your needs.