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Lære Retrieving Distinct Rows | Retrieving Data
TEST SQL COURSE E2E
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Kursusindhold

TEST SQL COURSE E2E

TEST SQL COURSE E2E

1. Sorting Retrieved Data
2. Retrieving Data
3. Failing init script
4. Long execution init script

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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;
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Opgave

Swipe to start coding

You have to retrieve distinct (unique) continent values.

Løsning

Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Var alt klart?

Hvordan kan vi forbedre det?

Tak for dine kommentarer!

Sektion 2. Kapitel 3
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book
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;
copy
Opgave

Swipe to start coding

You have to retrieve distinct (unique) continent values.

Løsning

Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Var alt klart?

Hvordan kan vi forbedre det?

Tak for dine kommentarer!

Sektion 2. Kapitel 3
Switch to desktopSkift til skrivebord for at øve i den virkelige verdenFortsæt der, hvor du er, med en af nedenstående muligheder
Vi beklager, at noget gik galt. Hvad skete der?
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