Data Analytics - Module 3

What is SQL used for in data analysis?

To store, organize, and analyze large datasets efficiently

Why might someone choose SQL over a spreadsheet?

SQL is better for handling large or complex datasets that spreadsheets struggle to process

What environment is needed to use SQL?

SQL must run within a database that understands the SQL language

What are the three core components of a basic SQL query?

SELECT, FROM, and WHERE

Where does the SELECT clause do in SQL?

It specifies the columns to retrieve from a table

What does the FROM clause do in SQL?

It indicates the table where the data is located

What does the WHERE clause do in SQL?

It filters the query results based on specified conditions

How does SQL help analysts filter large datasets?

By using WHERE conditions to narrow down data efficiently

Why does capitalization and indentation useful in SQL?

They improve readability and make queries easier to review

Is a semicolon required in SQL statements?

It is recommended under ANSI SQL-92, but not always required

What does the LIKE operator do in SQL?

It performs pattern matching using wildcards like %

What is the purpose of SELECT * in SQL?

It retrieves all columns from a table, but may reduce performance if overused

What are two types of comments in SQL?

Single-line (--) and block (/ ... /) comments

Why are comments useful in SQL queries?

They clarify complex logic and make queries easier to maintain and share.

What is an alias in SQL?

A temporary name for a table or column used to simplify query writing

What does the operator <> mean in SQL?

It means "not equal to."

How can SQL help identify business issues?

By enabling analysts to retrieve, filter, and interpret data patterns and outliers

What does data visualization do?

It presents information graphically to make complex data easier to understand.

Why is data visualization important to stakeholders?

It helps them interpret insights quickly without reading raw data.

What chart types are commonly used in data visualization?

Bar charts, line graphs, and pie charts

What is an attribute

A characteristic or quality of data used to label a column in a table

What is an observation

The attributes that describe a piece of data contained in a row of a table