Is this database structure correct? Please help

[badmanmc]

I am fairly new to mysql and wanted to practice making a database and tables. As well as filling the tables with made up data and then practicing queries. I wanted to emulate a real life database project.

So I decided to make a database for a Car Dealership.

the database consists of three tables...Car...Buyer..Repairs. The structure is displayed below.

CAR table -

car_id int(5) primary key
make varchar(15)
model varchar(15)
year int(4)
origin varchar(15)
buyer int(5) foreign key references buyer_id in the BUYER table
cost double(5,2)

BUYER table -

buyer_id int(5) primary key
name varchar(20)
address varchar(20)
tel int(10)
car_id int(5) foreign key references car_id in the CAR table

REPAIRS table-

part_id int(5) primary key
origin varchar(15)
cost double(5,2)
car_id int(5) foreign key references car_id in the CAR table

(SCREENSHOT ATTACHED)

Do you see any problems in this structure?
anything I should have done differently?
anything I could do to improve database performance?

Please bare with me as I am new to this and wish to be a DBA one day soon!

All comments will be appreciated!!

Thanks people

[timothybard]

Here are some recommendations I have:

1) Remove the car_id field from the buyer table; what is the purpose of that field?
2) Create a table to track the make of the car; instead of typing in the make for each car in the car table, I would use a table to track all the makes of cars.
3) Create a table to track the model of each car.
4) Break out the repairs table; I would use one table to track when a person brings in a car for a repair and use another table to track all the parts that need to be worked on during the repair session.

[badmanmc]

Thanks!!

Really appreciate the reply it really helps. The reply doesnt just help me with this database but helps me in learning the best practices of database design.

Thanks :)

[pclfw]

Have a look through this http://www.geekgirls.com/databases_from_scratch_1.htm

Very good intro to DB design.