Introduction to Modern Databases/

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SELECT Queries Basics

SELECT Queries Basics

Learn how to query, filter, sort, and rename data using essential SQL SELECT statement.

We'll cover the following...

Suppose the CEO of our OnlineStore asks: Which of our products are the most expensive? Or can I get a list of all our VIP customers?. We wouldn’t want to scroll through thousands of rows of raw data to find the answers. This is where SELECT queries come in!

They are the primary way we ask questions and retrieve specific information from our database. It’s like having a conversation with our data, where we ask precisely for what we need and get a clear, organized answer.

By the end of this lesson, we will be able to:

  • Understand the fundamental structure of a SELECT query.

  • Retrieve all or specific columns of data from a table.

  • Filter data to get only the rows that match our criteria using the WHERE clause.

  • Sort the results in a meaningful way using the ORDER BY clause.

  • Rename columns in our output for better readability using aliases.

SELECT statement

The SELECT statement is the most frequently used and fundamental command in SQL. Its primary function is to retrieve (or select) data from one or more tables. Think of it as the command used to access and view information without altering the underlying data. Whenever data retrieval from a database is required, the process typically begins with the SELECT statement.

The most basic structure of a query involves two parts: ...