Relational Database Context Diagram (1 Viewer)

[bradyjoosse]

Hey,

For the first assessment task for IPT we are doing databases and we have to create a relational database then a context diagram (along with some other stuff which I am confident with). I am unsure how to go from an Schema/ERD to a context diagram and understanding how to draw one. I am just asking at the moment before I have actually created the database within Microsoft Access (but I do have my dataset I am using).

I hope someone can help it would be greatly appreciated

 

[cossine]

Hey,

For the first assessment task for IPT we are doing databases and we have to create a relational database then a context diagram (along with some other stuff which I am confident with). I am unsure how to go from an Schema/ERD to a context diagram and understanding how to draw one. I am just asking at the moment before I have actually created the database within Microsoft Access (but I do have my dataset I am using).

I hope someone can help it would be greatly appreciated

So you just need to know what context diagram is. Context diagram and ERD are two completely different concepts.

 

[bradyjoosse]

So you just need to know what context diagram is. Context diagram and ERD are two completely different concepts.

I do know what a context diagram is I've just not had them in the context of databases until now. I've made a few before I am just struggling to understand what sort of things I need to do in the context diagram for it to be correct for a relational database.

 

[jimmysmith560]

The following screenshots are from my database project for a fictional company called "Sharma Landscaping Equipment" back when I did my HSC. I thought I'd include them as an example, hoping that you would find them useful:



This is the set of relationships that my database had based on the tables that I had created.



This was the context diagram I had made based on the database.

I hope this helps!

 

[bradyjoosse]

The following screenshots are from my database project for a fictional company called "Sharma Landscaping Equipment" back when I did my HSC. I thought I'd include them as an example, hoping that you would find them useful:

View attachment 36951

This is the set of relationships that my database had based on the tables that I had created.

View attachment 36952

This was the context diagram I had made based on the database.

I hope this helps!

Thank you so much this is exactly what I needed comparing the ERD with all the relationships to a context diagram out of curosity how would a database junction (joining table / the sub entity that connects two entities together) work in an context diagram or does it not matter / not included?

 

[jimmysmith560]

Thank you so much this is exactly what I needed comparing the ERD with all the relationships to a context diagram out of curosity how would a database junction (joining table / the sub entity that connects two entities together) work in an context diagram or does it not matter / not included?

No worries. If I correctly understood your question, I think that you just need to assess the significance of all main entities and identify those that are the most important, which would then be included in the context diagram as external entities. In my case, only customers and suppliers were suitable as external entities to be included in the context diagram.

 

[bradyjoosse]

Hey @jimmysmith560 its been a while as I have done it in access and doing the context diagram now I am still struggling to understand converting it I have attached a screenshot of my access relationship diagram.



Thanks

 

[jimmysmith560]

Hey @jimmysmith560 its been a while as I have done it in access and doing the context diagram now I am still struggling to understand converting it I have attached a screenshot of my access relationship diagram.

View attachment 37048

Thanks

Hey @bradyjoosse, I think that a bit of context as to your project would be beneficial to better understand the nature of the different elements as well as the relationships between them. From your attachment, I believe that your context diagram could look something like this:

​

In addition to the packer entity, this context diagram assumes the existence of an inventory given the InventoryItem element. Of course, whether this is applicable to your project is something that you can determine or perhaps manipulate.

 

[bradyjoosse]

I think that a bit of context as to your project would be beneficial to better understand the nature of the different elements as well as the relationships between them.

Its an relational database for an inventory system for a school "tech team" which has different pieces of equipment such as cameras which are stored in packers which are pretty much pelican cases and flight cases.

 

[bradyjoosse]

Does the sort of diagram you have done work for my context I mean it makes sense kind of but unsure.

 

[jimmysmith560]

Does the sort of diagram you have done work for my context I mean it makes sense kind of but unsure.

While I created the initial context diagram without much context (no pun intended), I believe that it would still work. Minor adjustments would be required to reflect the exact details (such as the actual name) of your system.

Its an relational database for an inventory system for a school "tech team" which has different pieces of equipment such as cameras which are stored in packers which are pretty much pelican cases and flight cases.

Now that you have provided this information, perhaps the context diagram could be adjusted to look as follows:



In such a case, the inventory system handles requests made by the school tech team accordingly.

 

[bradyjoosse]

While I created the initial context diagram without much context (no pun intended), I believe that it would still work. Minor adjustments would be required to reflect the exact details (such as the actual name) of your system.



Now that you have provided this information, perhaps the context diagram could be adjusted to look as follows:

View attachment 37087

In such a case, the inventory system handles requests made by the school tech team accordingly.

Ok thank you so much for your time and effort this has been a great help to my understanding to use in the future.