It is known about each employee of the shipping company what their
first and last names are, their age, residence address, place of
birth, correspondence address, e-mail.
Each employee who is a driver has one of the cars at the disposal. It
is known about the car what make it is, what engine it has, when it
was manufactured, etc.
Each car has a vehicle card, which contains information on failures,
services, repairs, etc.
Shipping company has its customers and gathers the following
information about them: first and last names, address, telephone no.
Customers commission the company the shipping of commodities. About
commodities the following information is known: quantity, weight,
address and date of shipping.
Customer can commission the shipping of more than one commodity. It is
also known what the price of such a service is.
Please, review this ER Diagram that I have designed.
I have used "Look Across" Min-Max notation.
I would slightly change the diagram to display the shipping order as an entity (currently in your diagram it's displayed as a relation), with the following :
Each customer can have many shipping orders.
Each shipping order can contain many commodities.
Hope this helps
Related
I have these set of requirement:
For each school, the system needs to keep track of its unique name, address, classification (Value could be Elementary, Middle, or High), and number of students studying in it.
For each School System Employee, we need to keep track of the unique employee number, full name, address, salary, and the school where (s)he works. An individual works only in one school.
For each student, we keep track of the student’s name (at times, we need to refer to student’s first name, middle initial, and last name individually), address (at times, we need to refer to the street address, city, state, and zip code individually), the school (s)he attends, and what grade (s)he is in.
The system sends letters to High School students frequently, and hence, needs to keep track of each High School student along with the year when (s)he enrolled in the High School.
A system-wide list of courses offered is kept. Information about a course consists of its unique number, unique title, and number of credits.
For each school, the information about which courses are taught there is kept.
For each student, we keep a grade report that provides the grade (Value could be A, B, C, D, or F) for the student for a specific course.
The School System owns buses which are identified uniquely by their registration numbers. Some students take them to commute between their home and their school, while others use their personal means to commute. We keep track of which student takes which bus to commute. We also keep track of drivers assigned to buses (a driver is a school system employee who could be assigned to multiple buses, and a bus could have multiple drivers assigned to it – consider this a weekly assignment of buses and drivers).
Here is my attempt at the ER design:
This is my first ER design and i just wanted to know if met all the requirements and if I did it correctly? Any help will be much appreciated! Thanks!
First of all I don't like it to omit columns necessary for forein keys, e.g. a school ID in the employee table. But I don't know enough about ER diagrams to say if that would even be allowed.
The diagram looks fine to me. Some points though:
School names can change. If there is a number system available (such as NCES School ID for USA) I'd make this the PK instead.
Numbers of students must be no column in the school table; the number of students per school is implicitly given by the students related to the school.
I don't like 1:1 relations very much. Student <-> High Schooler is okay, but I'd rather have the enrollment date in the students table.
StudentID alone can't possible the PK for the grades table. It must be StudentID + Course# instead.
The line from student to course is superfluous, because the relation is given by the grades table already (which is a bridge table containing StudentID, Course# and an optional grade).
The course table's PK must not be Course# + Title, because that would mean the same course number would be allowed in combination with different titles. The PK should be the course number alone. As to the relation: I don't know if the same course can be taught at different schools. If so, the relations are correct.
Met. (though I'd break appart address into # StreetAddress, PO Box, city, state zip etc.(assuming US) Though if you want extra credit you could subtype addresses into their own table and simply have the employee, student and school addresses all in one table with a foreign key...
I'd break down Name, address just as habbit always go to
the loweest common denominator: Fname, LName, etc... (for scaling
solutions long term; combining data is easy, breaking it out later
is hard)
Looks good
Doesn't grade define Highschool? a 9th
grader is in highschool right? so why a seperate table?
4.1) now a table which lists what letters were sent to what students might be useful... but they didn't say they needed this so I'd seek clarification on the requirement.
if # is unique title doens't need to be part
of key.
Missing (you need a schoolCourses table)
Missing (I guess could be handled through your grade table though) Id call the table studentcourses and keep grade on the table... then yeah it works.
Associative/Junction table between bus/student and bus/employee
needed
Overall many-to-many need to be resolved as part of modeling. and I agree with Thorsten, I want to see all fields in all tables including the FK's and I've done enough to know the CASE tools allow it.
and while 1-1 relationships look good for 4/5th normal form. they generally are not practical anymore unless the truely represent a separate concept. So I may have a vehicle table for a vehicle database but I may also have a table for car attributes vs motorcycle attributes vs truck vs boat etc... but vehicle is the primary in this case there so little reason to separate out high school I just don't see the long term value of keeping the object separate (but maybe I just lack vision).
You'll learn that in ERD's the cardinality of the relationships between the data is THE MOST IMPORTANT (following datatype/size/scale precsion). Eliminating M-M relationships is a must. and everything really boils down to 1-M or 1-1 when your done.
Not sure what the line between the school/bus implies.... the buses are owned by the whole system... maybe you need a "System" table tie that to the schools and buses to the system. that way if you support multiple school systems you know which buses belong to what system and what schools are in what system...
I am currently working on a project relating to a medicine stock management system on vb.net.
Basically I have 3 tables in a MySQL database that I will link to my program; orders, current stock, and medicine.
Each order has an autoincrementing order reference, delivery date, units ordered and the reference number of the medicine that has been ordered.
The stock table contains all the medicine names which are in stock, how many units are in stock, the cost price and the retail price.
Finally, each medicine has a reference, a name, and a supplier name.
The tasks I would like to perform throughout my program are:
1- Store and add medicines to the system
2- create, edit and view orders
3- view medicines in stock and the amount of units present
4- search for a specific field in each of these tables
I am quite new to object oriented programming and Vb.net so I would like to know what is the best approach to design this program?
1- Windows form based application with no inheritance seeing that I have only 1 type of product (separate classes for everything)
2- Windows form based but with inheritance and an interface
3- any other more efficient approach?
If I were to choose option 2 I would require just a few guidance tips on what my baseclass should probably be.
Thank you
Well, technically speaking, this is not a stock management system only, if you are including orders. Stock is only the part taking care about stocking items.
What you look for, in a nutshell, is probably:
(Purchase)Orders: Handle their logic separately from stock logic. You will need Orders (List of orders) and OrdersLines tables. I'm just guessing, that you mean Purchase Orders.
(Customer)Orders - you will need similar for Customer Orders, if you don't sell the goods in shop, but to a partners per Invoices.
Item: Table Item - ut will hold details of each medicine - columns like, ItemNo, Name, Description, OrderCode, VendorReference, ReferencePicture, Price (if you have different prices for different quantities, you will need another separate table ItemPrices with ID linked to foreign key of Items), etc.
Stock: Tables StockCards (each linked to Item, it is to store data like minimum, maximum a and actual stock level, you might pre-define stock location), StockRecords (to record movements of goods in and out of stock), you can have also a separate StockLocations
And as for interface, I reccomend to do a List and Detail VB.NET form for each table. List will contain list of items and filters to find what you want. The Detail page will allow to show all the deatails and edit them. You can then load the forms into i.e. TabControl in your main application. And combine them, i.e. put a List into left panel of SplitContainer and detail into right one, and use DataGridView's CellClick to load item into the Detail module.
Im trying to build a hotel application system and now i have laid out plans for the DB. My requirements are a guest searches for availability for a room. A room could either be king or queen, and smoking or non smoking. Also the guest enters the check in and out date. Based on the search the guest enters their info and reserve a room. Based on the reservation the service agent receives the receipt(reservationId). The service agent books the room upon receiving the reservationId. A guest can reserve several rooms per reservation. Now below is how my DB looks right now.
My question is since a guest can have several rooms per reservation how could i represent multiple rooms per reservation. Note: This will be done using hibernate. And below is my actual setup now for my DB please feel free to correct me if my approach is wrong: Below is a draft of how my db looks:
Reservation(resId(PK), checkIndate, checkOutDate, roomType, roomProperties, guestId(FK)).
Guest(guestId(PK), fname, lname, email, license, address_details).
Room(roomId(PK), roomNumber, roomProperties, roomType, price).
Booking(bookId(PK), resId(Fk), roomId)
RoomOccupied(bookId(PK and FK), roomId(PK and FK), flagChecKIfOccupied(default value is 0 if not occupied or 1 if occupied)
Payment(paymentId(PK), resId(FK), finalPayment)
I am trying to attribute supplement sales to doctors. Ideally, our sales reps would code for this during checkout and the doctor would be represented in a field called 'provider code'. However, due to human error/ just not knowing who a patient's doctor is the sales reps will code the sale generically, and will code this as 'TEAM' under provider code.
When I run a report in crystal reports I have grouped the transactions by another field, 'Patient ID'. Although the sales are coded generically, based upon the Patient ID grouping it becomes fairly obvious as to which doctor vitamin sales should be attributed.
My problem has been how to write a report which recognizes those vitamin sales coded as 'TEAM' uniquely. I have tried to tackle the problem in a few ways but all have focused on trying to have the report recognize that being within a certain group (i.e. a group where a provider code other than 'TEAM' is present) acts as a unique identifier.
Any and all help would be greatly appreciated! Thank you in advance for your time!
EDIT: Data Example
**214**
ProviderCode PatientID TxnCode Amount
JLK 214 Cxxx xxx.xx
TEAM 214 Vxxx xxx.xx
So the report is grouped primarily by Patient ID. It seems intuitive that vitamin sales grouped next to a clinical code (which can only be attributed to a provided) should be attributed to that provider, in this particular case, JLK.
I want to have a field which summarizes the vitamin sales for each provider at our clinic.
I'm working on my final project for an intro to Access DB class. My assignment is a general "Create a DB with at least 3 tables, of which 2 are linked," with some specific requirements for types of tables (customer relations, financial management, product/service-related data).
I decided to create a database for a fictional airline. I need to track financial information, particularly the sale of tickets. I have a tblFlights table that includes a BaseFare field, a tblAirports table that includes airport fees and airport taxes and a tblInvoice table that currently only has invoice number and customer ID fields in it. I suppose that I would use a report to generate an actual invoice, not a table, right? So, I don't want to store a bunch of financial data in an invoice table, and maybe I shouldn't even have an invoice table? How do I keep track of how much money customers owe and how much they have paid?
I suppose that I would use a report to generate an actual invoice, not a table, right?
Yes, use a report.
So, I don't want to store a bunch of financial data in an invoice table, and maybe I shouldn't even have an invoice table? How do I keep track of how much money customers owe and how much they have paid?
Well, I suppose some industries might be able to get an airline to send them in invoice, but I've never heard of that myself. In my experience, you pay first, then they give you the ticket. So I'd expect a table of tickets, which would identify the flight, the seat (or its equivalent), the person's name, and something to indicate that it's paid (a Boolean flag, a price, something like that).