-- (Comment) (Transact-SQL)
Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)
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.
Transact-SQL syntax conventions
To view Transact-SQL syntax for SQL Server 2014 and earlier, see Previous versions documentation.
Is the character string that contains the text of the comment.
Use two hyphens (--) for single-line or nested comments. Comments inserted with -- are terminated by a new line, which is specified with a carriage return character (U+000A), line feed character (U+000D), or a combination of the two. There is no maximum length for comments. The following table lists the keyboard shortcuts that you can use to comment or uncomment text.
|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).
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