Help dbms

[diya.]

assalamualikum to all


guyz yha per koi database ka bnda ya dnde hay ...

mjhy kuch help chahye dbms say related....


thankx

 

[Don]

post your question. I might help.

 

[diya.]

hamare event management per project hay to phr mjhy event managemnet system ki ER DIAGRAM CHAYE THE

i search on net but i cant find it...

 

[diya.]

and i have another question related to this but this one is little bit long ..can i pm u

 

[Don]

you can pm or post it here..

 

[diya.]

ER diagram ka bta day DON... AND dosra question may ap ko pm kr dati ho

 

[diya.]

You required to create a conceptual data model of the data requirements for a company that specializes in IT training.The company has 30 instructors and can handle up to 100 trainees per training session.The company offers five advanced courses each of which is taught by a teaching team of two or more instructors.Each instructors is assigned to a maximum of two teaching teams or may be assigned to do research.Each trainee undertakes one advanced technology course per training session


(a)Identify the main entity types for the company
(B) Identify the main relationship types and specify the multiplicity for each relationship.State any assumptions u make about the data
(c) Using ur answer for (a) & (B) draw a single ER diagram to represent the data requirements for the company

 

[Don]

Entity Relationship(ER) diagram banane k lie ap ko sab say pehle possible Entities verify karni hoti hai.
in your case, kuch entities yeh hongi [Instructor, Trainee, Course etc etc] Each entity can have many attributes.

us k baad ap ko Relationship define karna hai har entity ka. For Example: Intructor ka relationship Trainee k sath and then dono ka relationship Course/Program k sath.

There can be One To Many Or One to One or Many to Many relationship.

ONE TO ONE:

one to one relationship is not very common. Yeh tab use hota hai jab kissi table ki ek attribute ka relation dosray table ki ek attribute say ho. Is ki uncommon hone ki wajah yeh hai k jab single relationship hota hia to un ko ek sath hi rakh dia jata hai.
​

One To Many:

One to many is pretty common, yeh tab use hota hai jab ek attribute ka relation dosray table ki ek say zada attriubute k sath ho. For example: ek school may 1 teacher ka relationship bahut saray bacho k sath hota sakta hai laykin bahut saray bacho ka relation sirf ek teacher k sath hota hai (for one subject).​

Many to Many:

Many to many relationship tab occur hota hai jab ek table kaay multiple records dosray table k multiple records say correspond karte ho. for example:
Ek school may ek teacher kafi saray course perhata hai or un course may kafi saray bachay hote hain. is terhan Teacher or Course table ka relationship MANY to MANY ho ga.

​

Relationship build karnay k lie you can assign Foreign Key(FK). jo k table ko bata ta hai k wo kis terhan relate karta hai dosray table say.basically it links to the Primary key(PK) to related table. For example: ap k pass teacher or student ki do tables hain. ap student table may ek column add karein Teacher name ya id say jo k PK ho gi Teacher table ki. That way you can run strong queries through this relations.

------------

Now in your case. ER diagrams may basically ap ek box banate hain har entitiy ka alag alag box hota hai or us box k ander us entity k attributes hote hain. Then you jis entity ka relationship dosray entity k sath hota hai un dono ko ap ek line k throw connect karte hain.
Below is a good example of ER Diagram:

I hope you understand how database relationship works and what is ER diagram .. if you have any question do let me know.

 

[Don]

You required to create a conceptual data model of the data requirements for a company that specializes in IT training.The company has 30 instructors and can handle up to 100 trainees per training session.The company offers five advanced courses each of which is taught by a teaching team of two or more instructors.Each instructors is assigned to a maximum of two teaching teams or may be assigned to do research.Each trainee undertakes one advanced technology course per training session


(a)Identify the main entity types for the company
(B) Identify the main relationship types and specify the multiplicity for each relationship.State any assumptions u make about the data
(c) Using ur answer for (a) & (B) draw a single ER diagram to represent the data requirements for the company

Please not that do not simple copy paste my answer.
-----------

Ok so mere khayal say ap ko total 6 entities chaiye hain.

1. research
2. Instructor
3. Trainee
4. Advance course
5. Teaching Team
6. Training Sesseion

• So each instructor is assigned to a max of 2 teach team or may be assigned to do a research. so is terhan EK instructor ka relation many teaching team k sath banta hai or many research k sath.
• each course is taught by a teaching team of two or more inst. ek Teaching Team ka relation banta hai ek advance course k sath.
• ek advance course different session may teach kia ja sakta hai to is terhan ek Advance course ka relation banta hai Many Trainning Session k sath.
• Multiple sessions may Multiple Trainee hote hain is terhhan Many Training Session ka relation banta hai Many Traine k sath

---
Now you just have to draw that into a diagram:

again.. There may be some errors. maybe i got something wrong or maybe i have missed something.. So do not copy paste my answer blindly.

Regards,

 

[Hoorain]

sirf entities show ki
Relationship show nhi ki ?

 

[Don]

sirf entities show ki
Relationship show nhi ki ?

Is this not it ?

 

[Hoorain]

yup ye sirf entities hain ERD nhi hay

aisi hoing ERD na

Two entities direct kaise attach hoing aik dusre se withour any relationship

 

[Don]

I think you are talking about the attributes.. I did not bother with Attributes tho.
And the pic you have posted is very small I cannot read the text.

 

[Hoorain]

i m not talking about attributes attributes directly attach hote hain Entities k saath aik entity dusri entity k saath directly attach to nhi hoti darmayn may relationship hota hay Diamond shape k through,,maine ab tak jita parha us may to aise hi tha without relationship to nhi dekhi maine ERD,

ye simple si ERD's hain aap daikhain

ye hay main

Poora strucutre hay aur poori organization ya insititute may interdepartmental relationship ya system show hoga to hi diagram complete hogi na

 

[Hoorain]

ye aik hay aap k waali but is may bhi relationship Arrows k ooper show ki hay

 

[Don]

Well triangle wali diagram to may nay na kabi dekhi na kabi banai. Although second diagram may sirf relationship ko explain kia hai .. Arrows show karte hain relationship ko or un k upper jo text hai wo us ko describe kar raha hai. Yes I did not describe the relationship on the diagram. But it is possible agar ap Attributes may yeh bata dein k kon si Primary key hai or kon c Foreign Key to bi sense ban jata hai.

For example this diagram:

Is may nay to Triangle hai or na hi Relationship ko briefly describe kia gaya hai. laykin still yeh valid diagram hai kiun k is may define kia gaya hai kis entity ka kis k sath relation banta haii. but yes idher yeh nai bataya gaya k kaysa relation hai kiun k Database Software ko yeh janna zaroori nai hota hai yeh sirf hamare understanding k lie hai...

 

[Hoorain]

hmmmm ye iska to meko bhi nhi pta

 

[diya.]

Entity Relationship(ER) diagram banane k lie ap ko sab say pehle possible Entities verify karni hoti hai.
in your case, kuch entities yeh hongi [Instructor, Trainee, Course etc etc] Each entity can have many attributes.

us k baad ap ko Relationship define karna hai har entity ka. For Example: Intructor ka relationship Trainee k sath and then dono ka relationship Course/Program k sath.

There can be One To Many Or One to One or Many to Many relationship.

ONE TO ONE:

one to one relationship is not very common. Yeh tab use hota hai jab kissi table ki ek attribute ka relation dosray table ki ek attribute say ho. Is ki uncommon hone ki wajah yeh hai k jab single relationship hota hia to un ko ek sath hi rakh dia jata hai.
​

One To Many:

One to many is pretty common, yeh tab use hota hai jab ek attribute ka relation dosray table ki ek say zada attriubute k sath ho. For example: ek school may 1 teacher ka relationship bahut saray bacho k sath hota sakta hai laykin bahut saray bacho ka relation sirf ek teacher k sath hota hai (for one subject).​

Many to Many:

Many to many relationship tab occur hota hai jab ek table kaay multiple records dosray table k multiple records say correspond karte ho. for example:
Ek school may ek teacher kafi saray course perhata hai or un course may kafi saray bachay hote hain. is terhan Teacher or Course table ka relationship MANY to MANY ho ga.

​

Relationship build karnay k lie you can assign Foreign Key(FK). jo k table ko bata ta hai k wo kis terhan relate karta hai dosray table say.basically it links to the Primary key(PK) to related table. For example: ap k pass teacher or student ki do tables hain. ap student table may ek column add karein Teacher name ya id say jo k PK ho gi Teacher table ki. That way you can run strong queries through this relations.

------------

Now in your case. ER diagrams may basically ap ek box banate hain har entitiy ka alag alag box hota hai or us box k ander us entity k attributes hote hain. Then you jis entity ka relationship dosray entity k sath hota hai un dono ko ap ek line k throw connect karte hain.
Below is a good example of ER Diagram:

I hope you understand how database relationship works and what is ER diagram .. if you have any question do let me know.

thankk u so much DON .,..kafi had tk smjh b a gya hay ...

 

[diya.]

Well triangle wali diagram to may nay na kabi dekhi na kabi banai. Although second diagram may sirf relationship ko explain kia hai .. Arrows show karte hain relationship ko or un k upper jo text hai wo us ko describe kar raha hai. Yes I did not describe the relationship on the diagram. But it is possible agar ap Attributes may yeh bata dein k kon si Primary key hai or kon c Foreign Key to bi sense ban jata hai.

For example this diagram:

Is may nay to Triangle hai or na hi Relationship ko briefly describe kia gaya hai. laykin still yeh valid diagram hai kiun k is may define kia gaya hai kis entity ka kis k sath relation banta haii. but yes idher yeh nai bataya gaya k kaysa relation hai kiun k Database Software ko yeh janna zaroori nai hota hai yeh sirf hamare understanding k lie hai...

yha addrees r phone number per primary key nae lgae ge kia because yae to sb k unique hoty hay r jo unique hoty hay un per he primary key lgte hay i thnk

 

[diya.]

thankx hoorain for describing r yae jo ap nay traingle r entity ki shapes bne the yae me ko nae pata the bus erd may pata the k is is trha bnta hay ..thankx for ur reply