Tutorialsteacher

Follow Us

Articles
  • C#
  • C# OOP
  • ASP.NET Core
  • ASP.NET MVC
  • LINQ
  • Inversion of Control (IoC)
  • Web API
  • JavaScript
  • TypeScript
  • jQuery
  • Angular 11
  • Node.js
  • D3.js
  • Sass
  • Python
  • Go lang
  • HTTPS (SSL)
  • Regex
  • SQL
  • SQL Server
  • PostgreSQL
  • MongoDB
  • SQL Server - Get Started
  • Install SQL Server
  • SQL Server Management Studio
  • SQL Server - Windows Authentication
  • SQL Server - Authentication
  • SQL Server - Create New User
  • SQL Server - GRANT/REVOKE Permissions to User
  • SQL Server - Data Types
  • SQL Server - Naming Conventions
  • SQL Server - CREATE Database
  • SQL Server - CREATE Table
  • Add Columns
  • Identity Column
  • Rename Column, Table
  • Drop Columns
  • SQL Server - Schema
  • SQL Server - Tables Relations
  • SQL Server - Primary Keys
  • Modify/Delete Primary Keys
  • SQL Server - Foreign Keys
  • Modify/Delete Foreign Keys
  • SQL Server - Check Constraints
  • SQL Server - Unique Constraints
  • SQL Server - Views
  • Modify/Delete Views
  • SQL Server - Functions
  • SQL Server - Stored Procedures
  • Stored Procedure Parameters
  • SQL Server - Indexes
  • Non-clustered Indexes
  • Modify/Delete Indexes
  • SQL Server - Triggers
  • DDL Triggers
  • LOGON Triggers
  • Enable/Disable Triggers
  • Modify/Delete Triggers
  • SQL Server - Sequence
  • SQL Server - Synonyms
  • SQL Server - IF ELSE Statement
  • SQL Server - Loops
  • SQL Server - Insert Data
  • SQL Server - Update Data
  • SQL Server - Delete Data
  • SQL Server - Select Query
  • WHERE Clause
  • GROUP BY Clause
  • HAVING Clause
  • ORDER BY Clause
  • SQL Server - Inner Join
  • Left Join
  • Right Join
  • Full Join
  • Self Join
  • Dynamic SQL
  • Built-in Functions
Entity Framework Extensions - Boost EF Core 9
  Bulk Insert
  Bulk Delete
  Bulk Update
  Bulk Merge

SQL Server COUNT() Function

In SQL Server, the COUNT() is an aggregate function that returns the number of records in the SELECT query.

COUNT( [ ALL | DISTINCT] expression)

Parameters

ALL: Applies the aggregate function to all the values in the group. All values are counted. This is the default value.

DISTINCT: Applies the aggregate function to only distinct not null values.

expression: An expression of any type except text, ntext, or image.

The * specifies that the COUNT() function should consider all rows to arrive at the total table rows count.

  • COUNT(*) returns the number of rows in a table. This includes duplicates and null values.
  • COUNT(*) does not take any other parameter and does not support DISTINCT.
  • COUNT(*) does not need an expression as it does not use any information about any particular column.

Return Value

Returns an integer value.

Use the COUNT_BIG() function for return values bigger than 2^31-1.

Example 1:

In this simple example, the COUNT(*) returns the total number of rows in the Employee table.

Example: COUNT(*)
SELECT COUNT(*) AS EmpCount FROM Employee;

Example 2:

The following example get the total distinct departmentId value and the count of distinct DepartmentId value in the Employee table.

Example: COUNT()
SELECT COUNT(DISTINCT DepartmentId) AS UniqueCount, COUNT(DepartmentId) AS ActualCount FROM Employee;
TUTORIALSTEACHER.COM

TutorialsTeacher.com is your authoritative source for comprehensive technologies tutorials, tailored to guide you through mastering various web and other technologies through a step-by-step approach.

Our content helps you to learn technologies easily and quickly for learners of all levels. By accessing this platform, you acknowledge that you have reviewed and consented to abide by our Terms of Use and Privacy Policy, designed to safeguard your experience and privacy rights.

[email protected]

ABOUT USTERMS OF USEPRIVACY POLICY
copywrite-symbol

2024 TutorialsTeacher.com. (v 1.2) All Rights Reserved.