| title | Slash Star (Block Comment) (Transact-SQL) | ||||
|---|---|---|---|---|---|
| description | Slash Star (Block Comment) (Transact-SQL) | ||||
| author | rwestMSFT | ||||
| ms.author | randolphwest | ||||
| ms.reviewer | |||||
| ms.date | 07/27/2017 | ||||
| ms.prod | sql | ||||
| ms.prod_service | database-engine, sql-database | ||||
| ms.technology | t-sql | ||||
| ms.topic | reference | ||||
| ms.custom | |||||
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| monikerRange | = azuresqldb-current || = azuresqldb-mi-current || >= sql-server-2016 || >= sql-server-linux-2017 || = azuresqledge-current || = azure-sqldw-latest || >= aps-pdw-2016 |
[!INCLUDE sql-asdb-asdbmi-asa-pdw]
Indicates user-provided text. The text between the /* and */ is not evaluated by the server.
Transact-SQL Syntax Conventions
/*
text_of_comment
*/
[!INCLUDEsql-server-tsql-previous-offline-documentation]
text_of_comment
Is the text of the comment. This is one or more character strings.
Comments can be inserted on a separate line or within a [!INCLUDEtsql] statement. Multiple-line comments must be indicated by /* and */. A stylistic convention often used for multiple-line comments is to begin the first line with /*, subsequent lines with **, and end with */.
There is no maximum length for comments.
Nested comments are supported. If the /* character pattern occurs anywhere within an existing comment, it is treated as the start of a nested comment and, therefore, requires a closing */ comment mark. If the closing comment mark does not exist, an error is generated.
For example, the following code generates an error.
DECLARE @comment AS VARCHAR(20);
GO
/*
SELECT @comment = '/*';
*/
SELECT @@VERSION;
GO To work around this error, make the following change.
DECLARE @comment AS VARCHAR(20);
GO
/*
SELECT @comment = '/*';
*/ */
SELECT @@VERSION;
GO The following example uses comments to explain what the section of the code is supposed to do.
USE AdventureWorks2012;
GO
/*
This section of the code joins the Person table with the Address table,
by using the Employee and BusinessEntityAddress tables in the middle to
get a list of all the employees in the AdventureWorks2012 database
and their contact information.
*/
SELECT p.FirstName, p.LastName, a.AddressLine1, a.AddressLine2, a.City, a.PostalCode
FROM Person.Person AS p
JOIN HumanResources.Employee AS e ON p.BusinessEntityID = e.BusinessEntityID
JOIN Person.BusinessEntityAddress AS ea ON e.BusinessEntityID = ea.BusinessEntityID
JOIN Person.Address AS a ON ea.AddressID = a.AddressID;
GO -- (Comment) (Transact-SQL)
Control-of-Flow Language (Transact-SQL)