Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
Apprendre How many? | Selecting
SQL Basics
course content

Contenu du cours

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(*).

Tâche

Swipe to start coding

Count number of Audi cars sold from audi_cars table.

Solution

Switch to desktopPassez à un bureau pour une pratique réelleContinuez d'où vous êtes en utilisant l'une des options ci-dessous
Tout était clair ?

Comment pouvons-nous l'améliorer ?

Merci pour vos commentaires !

Section 1. Chapitre 6
toggle bottom row

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(*).

Tâche

Swipe to start coding

Count number of Audi cars sold from audi_cars table.

Solution

Switch to desktopPassez à un bureau pour une pratique réelleContinuez d'où vous êtes en utilisant l'une des options ci-dessous
Tout était clair ?

Comment pouvons-nous l'améliorer ?

Merci pour vos commentaires !

Section 1. Chapitre 6
Switch to desktopPassez à un bureau pour une pratique réelleContinuez d'où vous êtes en utilisant l'une des options ci-dessous
We're sorry to hear that something went wrong. What happened?
some-alt