MySQl and inheritance

[meethsingh]

kiddha ppl?

does anyone know if mysql supports inheritance (supertype/subtype relationships)?

if so, how is it achievied?

if not what are the alternatives..

[shindasingh]

What would you want to inherit in mysql??

[Guest]

Normally inheritence is a OOP concept not a database design thingy. In php you can create a class, that can be inherited by another class.

[meethsingh]

thanks for getting back to me.

as a simple axample, say if you had a type person with the attributes:

person(id, name, address, dob)

then you had a further two types say employee and student. each of theses types would have its own attributes:

student(department, grade, etc)

employee(position, salary, etc)

idealy you would want both student and employee to extend person and store the person attributes aswell as the individual attributes. (that is an employee also has [name, adress, etc] aswell as [salary, position etc])

i believe databases such as oracle and postgreSQL allow type inheritance. but i'm not sure about Mysql..

so i just wanted to know if Mysql supports type inheritance as i'm planning to use it on a project i'm working on.

[Guest]

I am not aware of type inheritence or a lot of database stuff as i normally get the databases prebuilt and just have to develop code for them. But What i do know of Db Design is that your probelm can be solved by traditional approach.

person(id, name, address, dob)

student(department, grade, fk:person_id)

employee(position, salary, fk:person_id)

As you can see that Each Student and Employee has a Record of Person type.

If you wanted to pull out name, address , dob for a student then you would just do a Join

[shindasingh]

Yea,

Unlike OOP the way to link or JOIN two fields in databases is by having the common id as explained by Amardeep Singh

[meethsingh]

singhs thanks for helping me out. i got my answer yesterday. its baiscally no.

looks like i got to redesign the database. :x

the use of foreign keys and a join never occured to me..... thanks! hopefully it will work.