DaniWeb IT Discussion Community - Database Design

Email /Messaging System Table design

yenyen — Wed, 14 May 2008 03:52:41 GMT

helo there, i need some help on database design for the email/messaging system. tis is one of the module. but i duno how to design the table structure and flow which involved : sender, receiver etc.
user A send msg/email to user B & user C, then the User B & user C can see the original msg from User A. after tat, user B reply msg to User A. User A can view the orignal msg + the replied msg and the user C also can view it .

another issues is i also have some problem in delete msg /email in each user mail box.

plz give me a hand.thank you.

Help, I'm Drowning

Fyrbeast — Wed, 14 May 2008 00:50:25 GMT

I was curious if anyone knows of a website that shows a step by step tutorials for relational DB development. I am just not getting much out of my textbook " Database Design for Mere Mortals"

Great book for someone who learns via reading, but for a visual learner. Quite difficult.

Thanks in advance for any thoughts.

Fyrbeast

Beauty Listings Design - Database?

geekchic24 — Tue, 13 May 2008 17:43:09 GMT

Hi,

I'm in the stages of building a beauty site that will include about 3,500 listings of salons & their services in my metro area. Since contact & service information changes consistently, I've considered a database driven website. In addition, I would like the search to pull results based upon either neighborhood, zip code, salon name, & service types.

I've been reading information about databases & PHP, but I'm still at a loss as to what is what. Currently, I have these salons listed in an excel spreadsheet. I need help figuring out the additional tools that I need to employ in this task.

So far, I know that I want to use PHP scripting (light). As for databases, I'm not sure. I saw that My Sql was mentioned as free in many articles, but I'm not sure if it is. So, all in all, I have an excel spreadsheet with 3500 listings, want to use PHP scripting, just need to know what type of database software is necessary/generic cost?

Btw, I have also ran across web-based databases. Are they any good? Also,can you use those with the PHP scripting? (odd question)

Thanks so much in advance!! Hopefully I learn more soon so I can contribute to users as well!
Nikki

DB Design

Kumar Arun — Mon, 12 May 2008 13:55:48 GMT

I am designing a database for inventory management for a wholesale dealer. In my case, the firm will receive stock allocation but the actual physical stock will only be received later. So some times the actual physical stock received may be less than the allocation or vice versa. excess or shortage of actual physical stock will be adjusted with the next month's allocation.
To make it complicated there might be price difference also.

At any give point of time, the opening, closing stock should be known.

Can you provide any suggestion / advices as to design a normalized DB structure for this scenario ?

E-commerce data design issue

daniyalnawaz — Mon, 12 May 2008 13:11:35 GMT

Hi, I'm designing a database for an E-commerce web project. It is a tennis equipment shop contains products such as Racquets, Balls, Apparels and other sports accessories. Each product have different sets of option (E.g Racquets have strings, tension, size and Apparels have color, size).

First I was planning to make three tables for products:
"PRODUCT" -|----------|O< "OPTION_GROUP" -|---------|< "OPTION"

Each product will have an option group and the group further will contains options. But there some options that are same in the products (Some tennis racquets have same option list for selecting strings) and some options differ in the size in different products (One racquet is available in 3 sizes ,while other one in 2). So i've decided to make following schema.

"PRODUCT" -|----|O< "PRODUCT_OPTION" >O|---|- "OPTION_GROUP" -|---|< "OPTION"

"PRODUCT_OPTION" will be a junction table containing product,options_group and option IDs to create many-to-many relation among the three table. I've included options in it because it is not necessary that product will have same size of options than the option_group actually contains. So now there will be only one group and junction table will specify what option group product contains and how many options are in it.

So hows my plan?... Am I mistaking somewhere or is there another way to create more efficient and optimized database.

Thank You!
Dara Daniyal

Attached Images

schema.jpg (19.2 KB)

ER Diagram Help

ranasingh1984 — Sun, 04 May 2008 12:37:41 GMT

I was wondering if you could help me with a current issue I am having whilst developing an ER diagram. The problem I am having is with identifying the correct Entities. The scenario I am trying to complete is given below. I have also included a list of entities which I think are needed, however I do not know if these are correct, could you suggest any possible entities and whether the ones I have identified are correct. I have also suggested a few possible relationships please could you assist me in determining whether these are correct.

SCENARIO
A heavy equipment hire company wishes to create a database to monitor the hiring of equipment to clients. The company has two types of equipment: power tools, such as drills and vacuum cleaners, and plants such as excavators and rollers. Power tools are described by their model and the voltage they use, whereas plants are classified by their model and their size in tonnes. The company has various outlets and each outlet has staff including a Manager and several Senior Technicians who are responsible for supervising the work of allocated groups of Technicians. Each outlet has a stock of equipment for hire that may be hired by clients for various periods of time, from a minimum of four hours to a maximum of six months. Each hire agreement between a client and the company is uniquely identified by using a hire number. The company insists that a client must take out an insurance cover for each equipment hire period. Each piece of equipment is checked for faults when it is returned by the client.

The Entities I have identified are as follows:

Equipment
Power Tools
Plants
Company
Outlets
Manager
Senior Technician
Technicians
Client
Hire
Hire agreement
Insurance

Company has * (many) equipment
Equipment has *(many) plants
Equipment has * power tools
Company has 1..* (many) outlets
Outlet has 1..1 manager
Outlet has * (many) senior technicians
Outlet has * (many) technicians
Outlet has for hire * (many) equipment
Outlet has * (many) clients
Client can hire 1..* (one to many) Equipment
Client can have 1..* (one to many) Hire Agreements
Client can have 1..* (one to many) insurance
Hire can have * (many) Hire Agreements
Hire Agreement has * (many) Insurance

As you may have established I am new to the field of ER Diagrams so I apologise for waffling on.

I will be grateful for any help

Regards

Help with simple database design!!

geebz — Fri, 02 May 2008 14:04:41 GMT

Hey guys I am an IT student and I am in a Intro Database class which is not my cup of tea. I have a simple database design project that I need to complete by monday and I just cannot figure it out. Can anyone Help me????

I attached the instructions in a word doc.Attachment 5938

Attached Files

db.doc (23.0 KB)

expandable tables?

jinx_uk_98 — Wed, 30 Apr 2008 09:17:49 GMT

Hi,

I'm creating a web database as a bit of learning project.

In short it's going to a on-line menu viewer, where people can upload (type in) their food/takeaway food menus.

The problem I'm having is with the design and as each outlet can have a differing number of starters/mains/deserts etc..

inital thoughts were:

Menus
------
Menu_id
Menu_outlet
Starter1
Starter2
Starter3
Starter4
etc...

but what if an outlet has more that 4 starters?

Can anyone point me in the right direction please?

thanks jinx

Difficulty to form Relations and Normalize

shouvik.d — Mon, 28 Apr 2008 13:36:03 GMT

Hi All,

We have many test artifacts and each unit is known as Unit Under Test (UUT). Each UUT is unique entity so it can be considered as a Primary Key.

Also there are various defect categories (viz. CAT-I,CAT-II). Moreover each Category can be broken down into exact defect name. so CAT-I would have a table of its own having the IDs for each of the exact defect. Similarly for CAT-II

Now each UUT can have multiple defects associated with it. e.g. UUT1 has a defect in CAT-I and two defects from CAT-II.

Now even if I have a foreign key I am not able to associate multiple defects to one UUT in form of a table. Can anyone suggest a good schema so that I can be able to associate a UUT to multiple defects.

I want to have the facility of bi-directional search like...I should be able to search what are the defects and what category in a UUT. Conversely I should also be able to find a defect exists in which UUTs.

Kindly guide me on this aspect. I had thought of a junction table with a many-to-many relationship but still I am not able to associate a single UUT to multiple Categories and the defect names inside each category.

I hope I could explain things properly.

Help with composite and Foreign Keys

HB25 — Sun, 27 Apr 2008 14:56:49 GMT

Dear Friends
I have finished the Data dictionary table for my assignment but I cannot figure out my (Composite and Foreign) Keys. I am attaching my physical data dictionary table with this massage. I would be very grateful if someone could identify them for me and update the table for me.
Thanks for your help in advance.
Regards
HB25

Attached Files

Data Dictionary and ERD.doc (66.0 KB)

database design (asp,sql server) for crm schedule calender

maziz — Fri, 25 Apr 2008 11:31:13 GMT

Hi All
I am new in development I want assistence in database design (asp,sql server) for crm schedule calender .
If you have any sujessions or link, i will like if you post them

Items with some, but not all, fields in common

estoyer — Thu, 24 Apr 2008 17:57:56 GMT

Greetings all,

I've been asked to create a database to track and report testing progress of a large number of IO points for an industrial plant. I can't seem to come up with an elegant way to split up the data, so I'd appreciate input from folks with more experience.

The IO points come in five "flavors" (sorry I can't go into detail; NDA issues). Every IO point has a certain number of fields in common -- port, channel, things like that. Additionally, each flavor has its own attributes which are irrelevant for all the others. So type A has port, channel, and foo; type B has port, channel, and bar.

They're all going into the same report, and I'd like to be able to sort just by port and channel, ignoring flavor. So on one hand, cramming everything into one table with fields for port, channel, foo, and bar, and then just leaving 9/10ths of the 'bar' values blank, is appealing. It would be easy to add new IO points and maintain unique port/channel combinations.

The downside is that there are so many flavor-specific fields that if I display a blank space in the report for every field that doesn't apply to a given flavor, it's going to get very crowded and very ugly. I might be able to hack something together in VB to hide the irrelevant fields, but it seems like that would be difficult to edit and maintain.

One alternative would be to put each flavor into its own table, and then have a report that pulls data from all 5. It seems like the queries involved would get messy and I'm not sure how much freedom I would have with sorting/displaying the final list of items. I'm not wild about having to use subforms for data entry either, but it's doable.

I've also considered putting the core data (port/channel) into one table, and then having five tables for the details -- one that only contains foo, one that only contains bar, etc. But in my extremely limited experience, this seems like a pretty unintuitive way to organize a database.

From a design/standards perspective, which would be the least-worst option? I'm leaving this project right around the time this database will start to see heavy use, so I want to make things as straightforward as possible for my successor.

Thanks.

ERD Diagram with inheritance

riniuia — Mon, 21 Apr 2008 07:34:17 GMT

Dear, friends,
I would like to know whether it is possible to draw ERD DIagram that has inheritance.
for example, For ASSET TABLE, it has 2 types of assets, PUBLIC ASSET and PRIVATE ASSET. Both table has several different attributes but both are ASSET. I'm thinking that in this case, it use inheritance (Is it right). If yes, so how the ERD Diagram will look like? also how to draw the relationship?
TQ

Quantity Per Unit value is not unique.

mezo — Sat, 19 Apr 2008 20:48:11 GMT

Hi all.
I'm experiencing an issue in my database design..
In my Products table I must assign a Quantity Per Unit column but the problem is the value of that column for the same product could be 5 or 6 or 7 .. how can I solve this problem in my database design..thanks

Newbie Question

sturner333 — Thu, 17 Apr 2008 17:54:41 GMT

Sorry for the lengthy question, but here goes:
I currently have an access database with a FE and BE that resides on each users laptop. Weekly they connect to the network and synch the BE the master on a network drive. There are numerous propblems with this as it has grown quite extensive.

We would like to have this be a server based database with the remote users either having access through the web or something else?

A few of the capabilities of the current database:
1. generate and print reports 2. update project forms. 3. enter time logs 4. enter notes

My question is:
What are my options for a remote FE? I am well versed in VB6 and Access. Would be willing to learn other languages (VB.net, my SQL, etc.) Would I be able to have the same functionality or would I have to have separate software for certain functions?