COUNT() - Cate Richter

The COUNT () function can count the number of records (rows) of a given table.

SELECT count(column_name)
FROM table_name;

Example1:

We have a table Customer with this data:

CustomerID	Name	Hair	Salary
1	Alechandro	brown	100
2	Katerina	blonde	150
3	Lucie	blonde	30
4	Thomas	black	40
5	Theodor	black	120
6	Thomassino	black	99
7	Knor	brown	50
8	Thor	blonde	10
9	Lucie	pink	70

SELECT count(name)
FROM Customer;

The result is 9. We have a total of 9 lines with the name filled in.

COUNT(NAME)
9

Example2

Now we are interested in unique names from the Customer table.

SELECT count(distinct name)
FROM Customer;

The result is 8. We have a total of 8 unique lines with the name filled in.

COUNT(NAME)
8

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