SQL COUNT() Function

Oct 22, 2024Ikki

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The COUNT() function returns the number of rows that matches a specified criterion.

Example

Find the total number of rows in the Products table:

SELECT COUNT(\*)  
FROM Products;

Syntax

SELECT COUNT(_column_name_) FROM _table_name_ WHERE _condition_;

Demo Database

Below is a selection from the Products table used in the examples:

ProductID	ProductName	SupplierID	CategoryID	Unit	Price
1	Chais	1	1	10 boxes x 20 bags	18
2	Chang	1	1	24 - 12 oz bottles	19
3	Aniseed Syrup	1	2	12 - 550 ml bottles	10
4	Chef Anton's Cajun Seasoning	2	2	48 - 6 oz jars	22
5	Chef Anton's Gumbo Mix	2	2	36 boxes	21.35

Specify Column

You can specify a column name instead of the asterix symbol (*).

If you specify a column name instead of (*), NULL values will not be counted.

Example

Find the number of products where the ProductName is not null:

SELECT COUNT(ProductName)  
FROM Products;

Add a WHERE Clause

You can add a WHERE clause to specify conditions:

Example

Find the number of products where Price is higher than 20:

SELECT COUNT(ProductID)
FROM Products
WHERE Price > 20;

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Ignore Duplicates

You can ignore duplicates by using the DISTINCT keyword in the COUNT() function.

If DISTINCT is specified, rows with the same value for the specified column will be counted as one.

Example

How many different prices are there in the Products table:

SELECT COUNT(DISTINCT Price)  
FROM Products;

Use an Alias

Give the counted column a name by using the AS keyword.

Example

Name the column "Number of records":

SELECT COUNT(\*) AS \[Number of records\]  
FROM Products;

Use COUNT() with GROUP B

Here we use the COUNT() function and the GROUP BY clause, to return the number of records for each category in the Products table:

Example

SELECT COUNT(\*) AS \[Number of records\], CategoryID  
FROM Products  
GROUP BY CategoryID;