DISTINCT Clause - ( SQL Server Clauses )

In SQL, the DISTINCT clause is used to return only distinct (unique) values from a query. It removes duplicate rows from the query results.

Syntax

The basic syntax for DISTINCT clause is as follows:

SELECT DISTINCT column1, column2, ...
FROM table_name
WHERE condition;

• DISTINCT keyword is used to remove the duplicates.
• column1, column2, ... are the columns to be retrieved.
• table_name is the table name from which the data is to be retrieved.
• WHERE is an optional clause to filter the results.

Example

Let's take an example of a students table:

id	name	age	course
1	Alice	20	Science
2	Bob	19	Arts
3	Charlie	21	Science
4	David	19	Commerce
5	Eve	20	Arts

SELECT DISTINCT course FROM students;

The query above returns the unique values from the course column:

course
Science
Arts
Commerce

Output

The output of the query is a table containing distinct values of the selected columns.

Explanation

The DISTINCT clause is used to filter out the duplicate values from the query result. The SELECT statement selects the specified columns from the specified table, and the DISTINCT clause ensures that only unique values are returned for the specified columns.

Use

Use the DISTINCT clause when you want to remove duplicates or retrieve only the unique values from a query.

Important Points

• The DISTINCT keyword is used to remove duplicate rows from the query results.
• The DISTINCT keyword is used in conjunction with the SELECT statement to select the specified columns from the specified table.
• The DISTINCT clause is used when you want to get unique values for the specified columns.

Summary

In this page, we discussed DISTINCT clause in SQL Server Clauses. We covered the syntax, example, output, explanation, use, important points, and summary of DISTINCT clause. The DISTINCT clause is used to select only unique values from a table or set of tables when running a query. It is useful in situations where you need to eliminate duplicates from the result set.