-- (Comment) (Transact-SQL)

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2008)yesAzure SQL DatabaseyesAzure SQL Data Warehouse yesParallel Data Warehouse

Indicates user-provided text. Comments can be inserted on a separate line, nested at the end of a Transact-SQL command line, or within a Transact-SQL statement. The server does not evaluate the comment.

Topic link icon Transact-SQL Syntax Conventions

Syntax


-- text_of_comment  

Arguments

text_of_comment
Is the character string that contains the text of the comment.

Remarks

Use two hyphens (--) for single-line or nested comments. Comments inserted with -- are terminated by the newline character. There is no maximum length for comments. The following table lists the keyboard shortcuts that you can use to comment or uncomment text.

Action Standard
Make the selected text a comment CTRL+K, CTRL+C
Uncomment the selected text CTRL+K, CTRL+U

For more information about keyboard shortcuts, see SQL Server Management Studio Keyboard Shortcuts.

For multiline comments, see Slash Star (Block Comment) (Transact-SQL).

Examples

The following example uses the -- commenting characters.

-- Choose the AdventureWorks2012 database.  
USE AdventureWorks2012;  
GO  
-- Choose all columns and all rows from the Address table.  
SELECT *  
FROM Person.Address  
ORDER BY PostalCode ASC; -- We do not have to specify ASC because   
-- that is the default.  
GO  

See Also

Control-of-Flow Language (Transact-SQL)