{"id":3592,"date":"2024-04-01T09:32:03","date_gmt":"2024-04-01T02:32:03","guid":{"rendered":"https:\/\/www.sqlservertutorial.net\/?page_id=3592"},"modified":"2024-04-01T09:34:56","modified_gmt":"2024-04-01T02:34:56","slug":"sql-server-count-star","status":"publish","type":"page","link":"https:\/\/www.sqlservertutorial.net\/sql-server-aggregate-functions\/sql-server-count-star\/","title":{"rendered":"SQL Server COUNT(*) Function"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to use the SQL Server COUNT<\/code>(*) to obtain the number of rows that meet certain criteria.<\/p>\n\n\n\n

Introduction to the SQL Server COUNT(*) function #<\/a><\/h2>\n\n\n\n

In SQL Server, the COUNT()<\/code> function is an aggregate function<\/a> that returns the number of values in a set of values.<\/p>\n\n\n\n

The COUNT(*)<\/code> is a form of the COUNT()<\/code> function that returns the total number of rows that meet certain criteria.<\/p>\n\n\n\n

In practice, you often use the COUNT(*)<\/code> to count rows in a table, whether any columns contain NULL<\/code> or duplicate values or not.<\/p>\n\n\n\n

Here’s the basic syntax of the COUNT(*)<\/code> function:<\/p>\n\n\n

SELECT<\/span> \n  COUNT<\/span>(*) \nFROM<\/span> \n  table_name;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
SQL Server COUNT(*) function examples #<\/a><\/h2>\n\n\n\n
Let’s take some examples of using the SQL Server COUNT(*)<\/code> function. <\/p>\n\n\n\n
We’ll use the production.products<\/code> and production.brands<\/code> tables from the sample database<\/a> for the demonstration:<\/p>\n\n\n\n
\"Sample<\/figure>\n\n\n\n
1) Basic SQL Server COUNT(*) function example #<\/a><\/h3>\n\n\n\n
The following example uses the COUNT(*)<\/code> function to return the number of rows in the production.products<\/code> table:<\/p>\n\n\n
SELECT<\/span> \n  COUNT<\/span>(*) product_count \nFROM<\/span> \n  production.products;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
product_count\n-------------<\/span>\n321<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
The output indicates that the products<\/code> table has 321 rows.<\/p>\n\n\n\n
2) Using the COUNT(*) function with a condition #<\/a><\/h3>\n\n\n\n
The following example uses the COUNT(*)<\/code> to retrieve the number of products whose list prices are greater than 900:<\/p>\n\n\n
SELECT<\/span> \n  COUNT<\/span>(*) product_count \nFROM<\/span> \n  production.products \nWHERE<\/span> \n  list_price > 900<\/span>;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
product_count\n-------------<\/span>\n139<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example:<\/p>\n\n\n\n
The query may include other clauses such as JOIN<\/a><\/code>, WHERE<\/a><\/code>, GROUP<\/code> BY<\/code><\/a>, and HAVING<\/a><\/code> clauses.<\/p>\n\n\n\n