Cursusinhoud
SQL Basics
SQL Basics
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:
SELECT COUNT(*) FROM visitors
Please note, that for counting the total number of rows you must place
*within parenthesis, likeCOUNT(*).
Swipe to start coding
Count number of Audi cars sold from audi_cars table.
Oplossing
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande optiesBedankt voor je feedback!
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:
SELECT COUNT(*) FROM visitors
Please note, that for counting the total number of rows you must place
*within parenthesis, likeCOUNT(*).
Swipe to start coding
Count number of Audi cars sold from audi_cars table.
Oplossing
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande optiesBedankt voor je feedback!
Schakel over naar desktop voor praktijkervaringGa verder vanaf waar je bent met een van de onderstaande opties