Cardinality and Targeted Data Template

DAD 220 Module Four Lab Javier Jackson 1/29/2025 Overview Begin by doing the following steps in the IDE (Codio): L oad the classicmodels data set . S tart a new terminal session and r un this command: mysqlsampledatabase.sql W rite commands to use the classicmodels database and show its tables to verify that you are in the right place. Then perform the steps below to complete the lab. Manually enter any commands you are asked to write. At the end of each step, replace the bracketed text in this template with your screenshot, response, or both, as indicated. Submit your completed template for grading and feedback. Screenshots should be sized to about one-quarter of a page. Written responses should be in complete sentences. Rename this document by adding your last name to the file name before you submit it. Identify Cardinality and Table Relationships Retrieve employee tuples and identify the number of employees in San Francisco and New York. Command for San Francisco: select firstName, lastName, jobTitle, offices.city from employees inner join offices on employees.officeCode = offices.officeCode where state = 'CA'. Write and run a command to return records from New York on your own. Validate the completion of this step with a screenshot of these two tables. Retrieve order details for orderNumber 10330, 10338, and 10194 and identify what type of cardinality this represents in the entity relationship model. Retrieve the order details by running SELECT queries with WHERE clauses against the Orders table. Now, identify what type of cardinality this represents in the entity relationship model. This represents a one-to-many relationship because one order can have multiple products. Delete records from the payments table where the customer number equals 103. Run a DESCRIBE statement to identify fields in the Payments table first. You are creating a file with any name you choose. Select the records from the Payments table for customer number 103 before deleting them. Delete the records from the Payments table for customer number 103. Run a SELECT statement against the table to show that customer number 103 is no longer there. Retrieve customer records for sales representative Barry Jones and identify if the relationships are one-to-one or one-to-many. Remember: SELECT, FROM, INNER JOIN, and WHERE. Use Barry’s employeeNumber, 1504, and perform a join between the customer salesRepEmployeeNumber to retrieve these records. Identify whether these entities demonstrate one-to-one or many-to-many relationships. the relationship between employees and customers is one-to-many, each sales representative can be responsible for multiple customers. Retrieve records for customers who reside in Massachusetts and identify their sales rep and the relationship of entities. Identify if these entities demonstrate one-to-one or many-to-many relationships. Remember: SELECT, FROM, INNER JOIN, and WHERE. Use employee.firstName and employee.lastName in your command. Identify whether these entities demonstrate one-to-one or many-to-many relationships or one-to-many. Since one employee can be responsible for multiple customers, but each customer has only one sales rep, this is a oneto-many relationship. Add one customer record with your last name using an INSERT statement. You may use the name of a celebrity or fictional character if you don’t use your own name. You may use the name of a celebrity or fictional character if you don’t use your own name. Think of this as your signature. Complete these actions to get to the right place to enter this information: (1) Show databases, (2) use classicmodels, (3) show tables, (4) describe customers; You should now see all of the fields that you’ll need to fill in to complete this step. Reference your Module Two lab or resources on how to populate these fields if you need to. Populate the following fields: customerNumber customerName contactLastName contactFirstName phone addressLine1 addressLine2 city state postalCode country salesRepEmployeeNumber creditLimit Run a SELECT statement on the Customers table and capture it in a screenshot. Reflection: Use the lab environment or the screenshots you’ve worked with for this step. Address the prompts below in your reflection. Write a paragraph in response to each prompt: Define how cardinality is applied to the databases you’ve been working with. Explain why different numbers of records were returned from the different offices. Cardinality in databases refers to the relationship between different entities and how many instances of one entity relate to another. In the classicmodels database, cardinality defines how tables like employees, customers, orders, and payments are connected. The varying number of employee records returned from different offices is due to how employees are distributed across office locations. Some offices may have a higher number of employees . Compare and contrast the different queries you ran and how cardinality applies to them. The employee office query represents a one-to-one relationship (one office per employee). The order details query follows a one-to-many relationship (one order has multiple products). The customer sales Rep query also follows a one-to-many relationship (one sales rep serves many customers). Describe two of the crucial benefits of cardinality in this type of database. c ardinality helps keep data organized by defining how tables connect, like linking orders to customers. It makes searches faster by storing data in a smart way and avoiding duplicates. Setting clear relationships, like one-to-many, prevents mistakes such as missing or extra records. This makes the database work better, stay accurate, and handle more data over time.