TEST SQL COURSE E2E

TEST SQL COURSE E2E

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1. Sorting Retrieved Data

In this section, we will learn how to sort retrieved data using the ORDER BY clause. This clause, which must be the last in the SELECT statement, can be used to sort data on one or more columns as needed.\n

Sorting by Multiple Columns

2. Retrieving Data

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.

Retrieving Individual Columns

Retrieving Multiple Columns

Retrieving Distinct Rows

3. Failing init script

This section has failing init script

4. Long execution init script

This section has long execution init script

Course Content

TEST SQL COURSE E2E

TEST SQL COURSE E2E

1. Sorting Retrieved Data

Sorting Data Challenge Sorting by Multiple Columns

2. Retrieving Data

Retrieving Individual Columns Retrieving Multiple Columns Retrieving Distinct Rows

3. Failing init script

4. Long execution init script

Retrieving Distinct Rows

Note that the SELECT statement returns all rows in a given column. Nevertheless, what if we don't need all the values from a column (because they can be duplicated), and we only need unique values? For such cases, it is convenient to use the keyword DISTINCT. Moreover, this keyword is used immediately before the column names. Let's look at an example.


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SELECT DISTINCT region FROM country;

Task

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You have to retrieve distinct (unique) continent values.

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Section 2. Chapter 3

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Retrieving Distinct Rows

Note that the SELECT statement returns all rows in a given column. Nevertheless, what if we don't need all the values from a column (because they can be duplicated), and we only need unique values? For such cases, it is convenient to use the keyword DISTINCT. Moreover, this keyword is used immediately before the column names. Let's look at an example.


              1
            
SELECT DISTINCT region FROM country;

Task

Swipe to show code editor

You have to retrieve distinct (unique) continent values.

Switch to desktop for real-world practiceContinue from where you are using one of the options below

Everything was clear?

Thanks for your feedback!

Section 2. Chapter 3

Switch to desktop for real-world practiceContinue from where you are using one of the options below

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