SQL Comments

SQL supports single-line comments

--, and multi - line comments

Note:

SQL Single-line Comments

Single-line comments start with

Any text after

The following example uses a single - line comment as an explanation:

Example

SELECT * FROM Customers
WHERE Country = 'Germany';

The following example uses a single - line comment to comment away the end of a line:

Example

SELECT * FROM Customers -- WHERE City='Berlin';

The following example uses a single - line comment to temporarily prevent execution of an SQL statement:

Example

-- SELECT * FROM Customers;
SELECT * FROM Products;

SQL Multi-line Comments

Multi-line comments start with

Any text between

The following example uses a multi - line comment as an explanation:

Example

SELECT * FROM Customers
WHERE Country = 'Germany' AND City = 'Berlin';

The following example uses a multi - line comment to ignore many SQL statements:

Example

/* SELECT * FROM Customers;
SELECT * FROM Products;
SELECT * FROM Orders;
SELECT * FROM Categories; */
SELECT * FROM Suppliers;

To ignore just a part of an SQL code, you can also use multi - line comment:

Example

SELECT CustomerName, /*City,*/ Country FROM Customers;

The following example uses a multi - line comment to ignore part of an SQL statement:

Example

SELECT * FROM Customers WHERE (CustomerName LIKE 'L%'
OR CustomerName LIKE 'R%' /*OR CustomerName LIKE 'S%'
OR CustomerName LIKE 'T%'*/ OR CustomerName LIKE 'W%')
AND Country='USA'
ORDER BY CustomerName;