The Online Food Ordering Database Task 2

The Online Food Ordering Database Task 2

CPT310: Database Systems & Management

Fields

Datatypes

Relationship

d_id

int

Primary key

d_username

varchar

d_password

varchar

d_firstname

varchar

d_lastname

varchar

d_email

varchar

d_phone

varchar

Fields

Datatypes

Relationship

n_id

int

Primary key

n_username

varchar

n_password

varchar

n_firstname

varchar

n_lastname

varchar

n_email

varchar

n_phone

varchar

Fields

Datatypes

Relationship

p_id

int

primary key

p_username

varchar

p_password

varchar

p_firstname

varchar

p_lastname

varchar

p_email

varchar

p_phone

varchar

Fields

Datatypes

Relationship

Diagid

int

primary key

Nid

int

foreign key

NurseComment

varchar (200)

Did

int

foreign key

Diagnostic

varchar (200)

Medicine

varchar (200)

Diagdate

date

The Chen ER diagram has some advantages to the original database that we first made. Being a IT student, we find that to understand a Chen ER diagram we must first know what one is. Chen is the last name for the designer of this diagram. Dr. Peter Chen developed the model in 1976 and was one of the first pioneers in developing this model as well as software to match the model. The next part of the ER diagram which is Entity-Relationship and is widely acknowledged in the computer industry because there are many valuable advantages to using the Chen ER diagram.

Advantages of Chen ER diagram

The model is used to show non-technical people what your plans are before any coding is done, which saves hours of coding time because you can show your client the work that is being requested beforehand. Another advantage of this is before any coding is done you can potential catch any coding errors and address them before you spend time coding the program. This program is your blueprint for design and you as the creator of the program that you will be coding will let you know what to refer to with any questions about your program. The best part of this diagram is will allow you to work out any complex issues from the beginning to get you to the next part of the program and enable you to get to the point of being able to code the program without any issues or concerns. Programming is done through coding but requires strict and concise keystrokes the simplest syntax error can cause you to have serious issues with the program not working properly. Also, with this concept you can get a better basic visualization of what the final product will look like when you complete the coding and the project.

Summary

The ER model as we learned in our textbook and through reading is a high-level data model which in turn gives us the diagrams that are needed to complete the work at hand and get the software out to the client. The Entity relationship uses database information to show you how things are related in the model. The ER model is based upon 3 concepts in which we found out in our text. The 3 concepts are: Entities, Attributes, & Relationships (Coronel & Morris, 2019). We also found that there can be weak entities and as our assignment shows those ones do not have a key attribute.

References

Coronel, C., & Morris, S. (2019). Database systems: Design, implementation, and management (13th ed.). Boston, MA: Cengage.

Enhanced entity-relationship model (Links to an external site.). (n.d.).

Ren, S., & Li, H. (2020). Question Answering Model Based on Graph Knowledge and Entity Recognition. 2020 12th International Conference on Measuring Technology and Mechatronics Automation (ICMTMA), Measuring Technology and Mechatronics Automation (ICMTMA), 2020 12th International Conference On, 578–581. https://doi-org.proxy-library.ashford.edu/10.1109/ICMTMA50254.2020.00129 

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