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Lernen Aliases | Selecting
SQL Basics

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Aliases

The outputs of the last two tasks were single columns with single values. If you noticed, this column had a name count, which is not, to be honest representative. Seems like it's only a matter of taste. But in the future, when you will work with multiple tables, will join one table to another, the same names will be a huge problem. Even from the point of interpreting the data.

In SQL you can easily declare a new name to a column by using AS statement. For example,

12
SELECT COUNT(DISTINCT(country)) AS "number of countries" FROM visitors
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This query will return a single value in the single column named number of countries, which is much readable than count.

Please note, that the aliases you use must be placed within double-quotes. Using single quotes will result in SQL error!

Aufgabe

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Extract unique types of fuel consumed by cars (column fueltype) and name this column as "Fuel type".

Lösung

Switch to desktopWechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwenden
War alles klar?

Wie können wir es verbessern?

Danke für Ihr Feedback!

Abschnitt 1. Kapitel 8

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book
Aliases

The outputs of the last two tasks were single columns with single values. If you noticed, this column had a name count, which is not, to be honest representative. Seems like it's only a matter of taste. But in the future, when you will work with multiple tables, will join one table to another, the same names will be a huge problem. Even from the point of interpreting the data.

In SQL you can easily declare a new name to a column by using AS statement. For example,

12
SELECT COUNT(DISTINCT(country)) AS "number of countries" FROM visitors
copy

This query will return a single value in the single column named number of countries, which is much readable than count.

Please note, that the aliases you use must be placed within double-quotes. Using single quotes will result in SQL error!

Aufgabe

Swipe to start coding

Extract unique types of fuel consumed by cars (column fueltype) and name this column as "Fuel type".

Lösung

Switch to desktopWechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwenden
War alles klar?

Wie können wir es verbessern?

Danke für Ihr Feedback!

Abschnitt 1. Kapitel 8
Switch to desktopWechseln Sie zum Desktop, um in der realen Welt zu übenFahren Sie dort fort, wo Sie sind, indem Sie eine der folgenden Optionen verwenden
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