Motor Driving School Er Diagram Software
Second part of our tutorial on how to create a database structure for a driving school's reservation system. This tutorial consists of 4 questions of ER diagrams. Q1 is a The Motor Vehicle Branch administers driving tests and issues driver's licenses. . created by instructors of the equivalent lectures at the University of New South. A Entity Relationship Diagram showing Driving school. You can edit this Entity Relationship Diagram using Creately diagramming tool and include in your.
I need a data model for a driving school to allow customers to make reservations for lessons online. The driving school may have more than one instructor and more than one vehicle.
How to Design Relational Database with ERD?
The instructor is assigned to the lesson upon reservation. The vehicle assigned to the lesson should also be recorded if the lesson takes place.
Let me start with my very first table for this model, and that is customer. It is to store master data for customers. It will make my data model extensible to cater to other service areas as well, like administrative and legal work, of a driving school.
Subsequently, one request is created in the request table, and all preferences are stored against the request in the same table.
At the time of request submission, one puts a preference for vehicle, i. However, the vehicle would actually be assigned to a lesson when it takes place. When a request is processed, reservations are made for each lesson of the service request.
All of these details are captured in another transaction table called reservation. I have highlighted all transaction tables with a different color than all master tables. This model allows a customer to cancel an individual lesson as well as the service request as a whole.
If customer cancels the service request, then all remaining lessons, which are scheduled for the customer, are cancelled in the reservation table. Please refer the data model created by me using Vertabelo for column level details of all these tables. A few points regarding column creation: Transaction tables are highlighted in blue in the data model created in Vertabelo.
I have purposely put this column in the staff table so that I can extend my data model to support an automated process to assign instructor to a request based on his or her location. My system should first look for an available instructor in the same or closest vicinity.
Relations are defined between tables for cross referencing. The way it stores data makes users easy to understand the structure and content of the data.
Developers may use Structured Query Language SQL to query data, and add indexes to database for faster querying, making relational database performs well even when the amount of data increases over time. Therefore, despite being challenged by object database for years, relational database still remains to be the most prevalent way of storing enterprise data to this date.
How Relational Database Works Relational database stores data as collections of tables. Each table contributes a set of columns, which are the properties of the table that are worthwhile and need to make persist.
Relationships, critical elements in relational database can be added between tables to indicate that two sets of data are inter-related. Table A relational database consists of a collection of tables i. A table consists of columns, which are the properties of the table, and rows which are the records to store and retrieve.
Column Columns refer to a set of fields in tables. A column describes a property we are interested in storing for the table it belongs to. Relationship A relationship is a connection between two entities.
- How Relational Database Works
- Related Diagrams
It connects data in tables together in meaningful ways. For instance, knowing the information of a transaction is meaningless without knowing the customer who performed the transaction.
Hence, we would relate the customer and transaction tables to obtain complete information about a transaction. School An entity relationship diagram ERD is a visual form of relational databases. People use ERDs to model and design relational databases.
The following is an ERD that depicts the tables for a simple school system. School and Student are entities note: In ERD, the term "entity" is often used instead of "table". They are actually the same. In the School table, there are two columns - id and name.
A primary key is capable in uniquely defining records in a table. In other words, there must not be two or more school records that share the same id. Student, another table, has a foreign key column, namely SchoolId. It is a reference to the primary key Id in the School table.
Driving school ( Entity Relationship Diagram)
Note that foreign keys need not be unique. Multiple student records can share the same School ID. In a real world scenario, there can be multiple students studying at the same school and therefore have the same school id. Between the School and Student entities, there is a connector.