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Lernen How many? | Selecting
SQL Basics
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Kursinhalt

SQL Basics

SQL Basics

1. Selecting
2. Filtering
3. Aggregating
4. Sorting
5. Grouping
6. Practicing

book
How many?

What if you want to know the exact number of observations in your database? Counting manually sounds like a very very bad idea.

Fortunately, SQL has the built-in functionality of counting rows. To count the number of rows in the whole dataset use COUNT *. For example, we can count the total number of our website being visited by using the following query:

12
SELECT COUNT(*) FROM visitors
copy

Please note, that for counting the total number of rows you must place * within parenthesis, like COUNT(*).

Aufgabe

Swipe to start coding

Count number of Audi cars sold from audi_cars table.

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 6
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book
How many?

What if you want to know the exact number of observations in your database? Counting manually sounds like a very very bad idea.

Fortunately, SQL has the built-in functionality of counting rows. To count the number of rows in the whole dataset use COUNT *. For example, we can count the total number of our website being visited by using the following query:

12
SELECT COUNT(*) FROM visitors
copy

Please note, that for counting the total number of rows you must place * within parenthesis, like COUNT(*).

Aufgabe

Swipe to start coding

Count number of Audi cars sold from audi_cars table.

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 6
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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