Comments make your SQL queries easier to read and understand.


-- single-line SQL comment

/* C comment, 
   can be multiple lines [*/]


Comments aren't SQL commands, but can occur in SQL queries. They are treated as whitespace by the parser. They can begin anywhere whitespace can be found, including inside expressions that span multiple lines.

Two styles of comments are supported:
SQL comments
These comments extend only to the end of the current line.
C comments
These comments can span any number of lines. If there is no terminating delimiter, they extend to the end of the input; this is not treated as an error. A new SQL statement can begin on the line after a multiline comment ends. C comments do not nest, and SQL comments inside a C comment are ignored.