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Questions and Answers
What is the primary purpose of data modeling?
What is the primary purpose of data modeling?
What are the three components of a data model?
What are the three components of a data model?
What is an example of a qualitative attribute?
What is an example of a qualitative attribute?
What is the first step in creating a data model?
What is the first step in creating a data model?
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What is an entity in the context of data modeling?
What is an entity in the context of data modeling?
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What is the purpose of the exercise in identifying attributes for different entities?
What is the purpose of the exercise in identifying attributes for different entities?
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What is a characteristic of a well-designed data model?
What is a characteristic of a well-designed data model?
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What is the final step in creating a data model?
What is the final step in creating a data model?
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What is the primary function of a Database Management System (DBMS)?
What is the primary function of a Database Management System (DBMS)?
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What is the relationship between a table and an entity in a relational database?
What is the relationship between a table and an entity in a relational database?
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What is the purpose of the SQL language in a relational database?
What is the purpose of the SQL language in a relational database?
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What is the function of the CREATE TABLE command in SQL?
What is the function of the CREATE TABLE command in SQL?
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What type of database management system is MySQL?
What type of database management system is MySQL?
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What is the correct syntax to create a new database in MySQL?
What is the correct syntax to create a new database in MySQL?
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What is the purpose of the USE command in MySQL?
What is the purpose of the USE command in MySQL?
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What is the correct syntax to insert data into a table in MySQL?
What is the correct syntax to insert data into a table in MySQL?
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What is the correct syntax to retrieve data from a table in MySQL?
What is the correct syntax to retrieve data from a table in MySQL?
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What is the correct syntax to update data in a table in MySQL?
What is the correct syntax to update data in a table in MySQL?
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Study Notes
Data Modeling Concepts
- Data modeling is similar to building design or engineering drawings in the real world
- A data model contains:
- Entities (things of interest that we want to store data about)
- Attributes (information about the entities)
- Relationships (how the entities relate to each other)
Entities
- An entity is something of interest that we want to store data about
- Entities can be physical real-world objects or conceptual things
- Examples of entities:
- Book
- Author
- Story
- News article
- Customer
- Address
Attributes
- An attribute is a specific characteristic or data point about an entity
- Attributes can be:
- Qualitative (non-numeric)
- Quantitative (numeric)
- Examples of attributes for a book entity:
- Title
- Number of pages
- Author
- Genre
Process of Creating a Data Model
- Step 1: Identify significant entities about which we want to store data
- Step 2: Create a logical data model to explain the relationships between entities
- Step 3: Determine the attributes for each entity
- Step 4: Design the database tables
- Step 5: Implement the design using Structured Query Language (SQL)
Exercise
- Identify at least 10 attributes for each of the following entities:
- Person
- Car
- Country
- Smartphone
- Bank account
- Class
- Pet
- Apartment
- Create a table with columns for:
- Attribute
- Data type
- Description
- Is it required or not?
Data Modeling Concepts
- Data modeling is a process of creating a conceptual representation of data structures and relationships.
- A data model consists of three key components: entities, attributes, and relationships.
Entities
- Entities are objects or concepts of interest that we want to store data about.
- Examples of entities include physical objects, people, and conceptual things.
- Entities can be classified into two categories: physical real-world objects and conceptual things.
Attributes
- Attributes are specific characteristics or data points about an entity.
- Attributes can be qualitative (non-numeric) or quantitative (numeric).
- Examples of attributes for a book entity include title, number of pages, author, and genre.
Process of Creating a Data Model
- The process of creating a data model involves five steps:
Step 1: Identify Entities
- Identify significant entities about which we want to store data.
Step 2: Create Logical Data Model
- Create a logical data model to explain the relationships between entities.
Step 3: Determine Attributes
- Determine the attributes for each entity.
Step 4: Design Database Tables
- Design the database tables based on the logical data model and attributes.
Step 5: Implement the Design
- Implement the design using Structured Query Language (SQL).
Database Management Systems (DBMS)
- A DBMS is a computer system that stores, organizes, manages, and processes data.
- It enables users to define, record, query, update, and manage data.
- DBMS provides functionality to create, host, and manage databases.
Relational Databases
- Relational databases store data in tables with relationships between them.
- This course focuses on relational databases, specifically MySQL.
Entities and Attributes
- Entities are real-life things about which we want to store data.
- Examples of entities include a person, a book, a car, or a building.
- Attributes are the data itself, which can be physical characteristics (e.g., weight, height, color) or other types of information.
Data Models
- A data model is a larger design that includes multiple entities and their attributes.
- It is a conceptual design that helps us organize and structure data.
- Data models are similar to building designs or plans.
Databases and Tables
- A database is a collection of entities, which are stored in tables.
- A table is a physical representation of an entity, with each attribute becoming a field within the table.
- A database can contain multiple tables, and each table can have multiple fields.
MySQL
- MySQL is a specific relational database management system (RDBMS) used for this course.
- It is a software that runs as a server, and can be accessed using a client application like MySQL Workbench.
- MySQL uses a language called SQL (Structured Query Language) to interact with the database.
SQL Basics
- SQL is a language used to interact with relational databases.
- There are six basic constructs in SQL:
- CREATE TABLE: creates a new table.
- ALTER TABLE: modifies an existing table.
- DROP TABLE: deletes a table.
- INSERT: adds new records to a table.
- UPDATE: modifies existing records in a table.
- DELETE: deletes records from a table.
Exercise
- Create a table about an entity called "person" with three fields: first name, last name, and gender.
- Use the CREATE TABLE command to define the table.
- Use the INSERT statement to add three records to the table.
- Use the SELECT statement to list the records.
- Use the UPDATE statement to modify the records.
- Use the DELETE statement to delete the records from the table.
Connecting to MySQL Server
- Use the username as your last name and student ID as the password.
- In the port session, leave the port number as 3306.
Configuring MySQL Workbench
- The main window is where you will type SQL commands and send them to the server.
- The left-hand side window displays databases, which can be expanded to show tables, views, stored procedures, and functions.
Creating a New Database
- To create a new database, use the SQL command
CREATE DATABASE. - The command should end with a semicolon (
;).
Creating a New Table
- To create a new table, use the SQL command
CREATE TABLE. - Define the fields (attributes) of the table, including data types and lengths.
Using the Database
- To use the newly created database, use the SQL command
USE. - Once inside the database, you can create tables, insert data, and perform other operations.
Inserting Data into a Table
- To insert data into a table, use the SQL command
INSERT INTO. - Specify the columns and values to be inserted.
Retrieving Data from a Table
- To retrieve data from a table, use the SQL command
SELECT. - Example:
SELECT first_name, last_name, gender FROM person;
Updating Data in a Table
- To update data in a table, use the SQL command
UPDATE. - Example:
UPDATE person SET last_name = 'Do' WHERE first_name = 'Jane';
Exercise Summary
- Create a database table called "person" with three columns: first_name, last_name, and gender.
- Insert three records into the table using the INSERT command.
- Retrieve the data from the table using the SELECT command.
- Update one of the records using the UPDATE command.
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Description
This quiz covers the basics of data modeling, including entities, attributes, and relationships. Learn how data modeling is similar to building design and engineering drawings.
