Comments

Use the comment notation to attach comments to statements, batches, and stored procedures. Comments are not executed and have no maximum length.

You can insert a comment on a line by itself or at the end of a command line. Two comment styles are available: the “slash-asterisk” style:

/* text of comment */

and the “double-hyphen” style:

-- text of comment

• Slash-Asterisk Style Comments
  The /* style comment is a Transact-SQL extension. Multiple-line comments are acceptable, as long as each comment starts with “/*” and ends with “*/”. Everything between “/*” and “*/” is treated as part of the comment. The /* form permits nesting.
• Double-Hyphen Style Comments
  This comment style begins with two consecutive hyphens followed by a space (-- ) and terminates with a new-line character. Therefore, you cannot use multiple-line comments.