The Lab For This Week Addresses Taking A Logical Database De

The Lab For This Week Addresses Taking A Logical Database Design Data

The lab for this week addresses taking a logical database design (data model) and transforming it into a physical model (tables, constraints, and relationships). As part of the lab, you will need to download the zip file titled CIS336Lab3Files from Doc Sharing. This zip file contains the ERD, Data Dictionary, and test data for the tables you create as you complete this exercise. Your job will be to use the ERD Diagram found below as a guide to define the table structures and constraints using both CREATE TABLE and ALTER TABLE statements. Once this has been done, you will need to write the INSERT INTO TABLE statements to insert the data provided into the table.

The data should verify that the constraints you have created are valid and define the correct referential and data integrity constraints asked for. Lastly, you will write SELECT statements to query the tables and verify the data was populated. Please use exactly the data provided, without addition, deletion, or alteration except as directed, as your results may be evaluated against expected results generated using this exact data set.

For this lab, you will be creating SQL statements to build a series of relational tables, using SQL CREATE statements in a script file format for the Student Database. You will then populate those tables through the use of INSERT statements with sample data.

You will need to create a script file and name it YourName_Lab3.txt containing the following code: the drop table statements listed later in the specifications of this lab, the CREATE TABLE statements necessary to build the six tables, the INSERT statements to insert all of the sample data, and six select statements to verify the data is in the tables and accessible.

To help you accomplish this, you are supplied with the ERD Diagram and the exact data to be inserted into each table, which can be found via the Doc Sharing tab. Use the names for the tables and columns as listed in the ERD; do not change them as it affects your grade.

Create all NOT NULL constraints, PK constraints, and FK constraints as indicated in the ERD. Create all tables and constraints before populating any tables with data. Since FK constraints will be enforced when inserting data, consider which tables must be created before others to avoid FK violations. For example, the COURSE table has a self-referencing FK for prerequisites—records with prerequisites must be inserted after their prerequisite records.

Some data contains FK constraints that cannot be resolved based on provided data. For such records, you should comment out or delete the insert statements for these records to avoid errors, without modifying or adding new data. All character strings in insert statements must be in single quotes; insert NULL without quotes when needed. Your script file must execute without errors and produce tables with data identical to the expected set.

Paper For Above instruction

The process of transforming a logical database design into a physical one involves meticulous translation of the ERD into SQL scripts that define table structures, constraints, and data insertion. This process ensures the database maintains data integrity, enforces relationships, and adheres to the original design specifications.

Introduction

Designing a relational database necessitates an understanding of both logical data models and the physical implementation within a database management system (DBMS). Logical design, represented by ER diagrams, provides an abstract view of entities, attributes, and relationships. Transitioning this into a physical schema involves creating appropriate tables, defining primary and foreign keys, enforcing constraints, and populating tables with sample data. This process ensures data consistency, integrity, and support for the application's requirements.

Creating the Database Schema

The initial step involves defining the database schema based on the ERD. Using the provided diagram, SQL CREATE TABLE statements are written for each of the six tables. These statements include column definitions with data types, NOT NULL constraints, and primary key (PK) constraints to identify unique records. For example, the Student table might include student_id as the PK, with columns for name, major, and other attributes. Each table’s constraints are carefully crafted to reflect the ERD specifications.

Creating constraints is crucial for maintaining data integrity. NOT NULL constraints guarantee that essential fields cannot be left empty. PK constraints ensure entity integrity by uniquely identifying each record. Foreign key (FK) constraints enforce referential integrity between related tables, such as linking students to their enrolled courses.

One of the complexities arises from self-referencing relationships, such as courses with prerequisites. The COURSE table contains a self-referenced FK to indicate prerequisite courses. Proper ordering of table creation and data insertion is necessary to prevent violations—prerequisite records must exist before dependent course records.

Additionally, some supplied data may contain references that cannot be resolved due to missing prerequisite records, intentionally designed as exercises. Such records, for example, with unresolved FK dependencies, are to be omitted to ensure script execution without errors.

Populating the Tables with Data

Once the schema with constraints is established, the next step involves inserting sample data into each table. Using precise INSERT INTO statements, data is loaded as per the provided datasets. Character strings are wrapped in single quotes, and NULL values are inserted without quotes. The order of insertion is critical to honor foreign key dependencies; parent records must be inserted before child records referencing them.

After data insertion, validation is performed through SELECT statements, retrieving all records from each table to verify correctness. The use of DESCRIBE and SHOW CREATE TABLE commands helps confirm that the table structures and constraints are properly implemented.

Testing and Validation

Execution of the entire script from beginning to end should produce a fully populated database with no errors. The validation process involves running select queries to inspect data accuracy. If errors occur, they are addressed by adjusting the insertion order, commenting out problematic data, or correcting constraint definitions. This ensures the physical model accurately reflects the logical design after implementation.

Conclusion

Transforming a logical design into a physical database involves precise SQL scripting encompassing table creation, constraint enforcement, data insertion, and validation. This process is fundamental for establishing a reliable, consistent, and functional relational database aligned with initial requirements and integrity rules. Proper management of foreign key dependencies, data integrity constraints, and data validation ensures a robust database capable of supporting application needs effectively.

References

• Elmasri, R., & Navathe, S. B. (2016). Database Systems (6th ed.). Pearson.
• Coronel, C., & Morris, S. (2015). Database Systems: Design, Implementation, & Management (11th ed.). Cengage Learning.