Create A Complete ERD In Crow’s Foot Notation

Create A Complete Erd In Crows Foot Notation That Can Be Impleme

Create a complete ERD in Crow’s Foot notation that can be implemented in the relational model using the following description of operations. Hot Water (HW) is a small start-up company that sells spas. HW does not carry any stock. A few spas are set up in a simple warehouse so customers can see some of the models available, but any products sold must be ordered at the time of the sale. HW can get spas from several different manufacturers. Each manufacturer produces one or more different brands of spas. Each and every brand is produced by only one manufacturer. Every brand has one or more models. Every model is produced as part of a brand. For example, Iguana Bay Spas is a manufacturer that produces Big Blue Iguana spas, a premium-level brand, and Lazy Lizard spas, an entry-level brand. The Big Blue Iguana brand offers several models, including the BBI-6, an 81-jet spa with two 6-hp motors, and the BBI-10, a 102-jet spa with three 6-hp motors. Every manufacturer is identified by a manufacturer code. The company name, address, area code, phone number, and account number are kept in the system for every manufacturer. For each brand, the brand name and brand level (premium, mid-level, or entry-level) are kept in the system. For each model, the model number, number of jets, number of motors, number of horsepower per motor, suggested retail price, HW retail price, dry weight, water capacity, and seating capacity must be kept in the system. An INVOICE is written by a SALESREP. Each sales representative can write many invoices, but each invoice is written by a single sales representative. The INVOICE is written for a single CUSTOMER. However, each customer can have many invoices. An INVOICE can include many detail lines (LINE), each of which describes one product bought by the customer. The product information is stored in a PRODUCT entity. The product’s vendor information is found in a VENDOR entity.

Sample Paper For Above instruction

Introduction

The design of a comprehensive Entity-Relationship Diagram (ERD) in Crow’s Foot notation is fundamental in establishing a clear blueprint for implementing relational databases. This paper articulates an ERD for Hot Water (HW), a start-up spa company, and integrates various entities, relationships, and constraints derived from the operational description provided. The objective is to create an ERD that accurately models HW’s operational realities, facilitates seamless database implementation, and ensures data integrity and normalization.

Entity Identification and Attributes

The primary entities extracted from the description include Manufacturer, Brand, Model, SalesRepresentative, Customer, Invoice, Line, Product, and Vendor. Each entity possesses specific attributes critical for operational and managerial functions:

- Manufacturer: manufacturer_code (PK), company_name, address, area_code, phone_number, account_number.

- Brand: brand_id (PK), brand_name, brand_level, manufacturer_code (FK).

- Model: model_number (PK), number_of_jets, number_of_motors, horsepower_per_motor, suggested_retail_price, HW_retail_price, dry_weight, water_capacity, seating_capacity, brand_id (FK).

- SalesRepresentative: salesrep_id (PK), name, contact_info.

- Customer: customer_id (PK), name, address, contact_info.

- Invoice: invoice_id (PK), invoice_date, salesrep_id (FK), customer_id (FK).

- Line: line_id (PK), invoice_id (FK), product_id (FK), quantity, unit_price.

- Product: product_id (PK), model_number (FK), vendor_id (FK), description.

- Vendor: vendor_id (PK), vendor_name, contact_info.

Relationships and Crow’s Foot Notation

The ERD models the following relationships:

- Manufacturer to Brand: One-to-Many (a manufacturer produces many brands).

- Brand to Model: One-to-Many (each brand has multiple models).

- Model to Product: One-to-One or One-to-Many (each model may correspond to one or several products, depending on configurations).

- Vendor to Product: One-to-Many (each vendor supplies multiple products).

- SalesRepresentative to Invoice: One-to-Many (a sales rep can write many invoices).

- Customer to Invoice: One-to-Many (a customer can have multiple invoices).

- Invoice to Line: One-to-Many (each invoice can contain many lines).

- Line to Product: Many-to-One (each line references one product).

The crow’s foot notation indicates "one" ends with a single line, and "many" ends with a three-pronged symbol, clarifying cardinality.

Normalization and Dependency Analysis

The ERD’s design adheres to normalization principles, primarily aiming for 3NF to reduce redundancy and ensure data consistency. The decomposition of composite dependencies and the elimination of partial dependencies underpin this normalization process, accommodating the complex relationships among manufacturers, brands, models, and sales transactions.

Implementation Considerations

Implementing this ERD involves translating entities and relationships into relational tables with appropriate primary and foreign keys. Referential integrity constraints will enforce relationships, and indexes will optimize query performance on frequently searched attributes like manufacturer_code, model_number, and customer_id.

Conclusion

A well-structured ERD in Crow’s Foot notation serves as the foundation for a reliable database system at HW. It delineates key entities, their attributes, and relationships, ensuring data integrity, facilitating operational efficiency, and supporting strategic decision-making. This design paves the way for implementing an effective relational database tailored to the needs of HW’s spa sales operations.

References

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