Summary  
This chapter covers the use of the asterisk wildcard (`*`) in a SQL `SELECT` statement to retrieve all columns from a table in a single query.  

General domain of usage  
Relational database querying

Instead of listing each column, you can use the asterisk `*` to retrieve all columns from the table at once. This is especially useful when you need to view all the data in a table without manually typing out each column name. Here’s an example:

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In this section, we will learn how to use the SQL SELECT statement to get a single table column, multiple table columns, and all table columns. We will also find out how to return unique values.

In this section, we’ll explore how to organize and prioritize the data returned by a query using the ORDER BY clause. Placed at the end of a SELECT statement, this clause lets you sort your results by one or multiple columns, either in ascending or descending order, enabling more meaningful and easily interpretable data output.

In this section, we will learn how to filter returned data using the SELECT statement's WHERE clause. We will learn how to test for equality, inequality, more and less significant than value ranges, and NULL values.

In this section, we’ll explore how to refine your search conditions by combining WHERE clauses with the AND and OR operators. We’ll also cover how the NOT operator can be used to exclude certain results.

In this section, we will learn what the SQL aggregate functions are and how to use them to summarize table data.

Retrieving All Columns

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