MySQL is not supporting single line comments here. What would be the reason?

问题

Here is what I am getting when I use single line comment (using --):

ERROR 1064 (42000): You have an error in your SQL syntax

Actually I am using these comments in a procedure to show what exactly a line does. Then I checked directly at the MySQL command line, but I got this error:

mysql> select 1;--test select
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

    -> ;
check the manual that corresponds to your MySQL server version for the right syntax to use near '--test select' at line 1

Do I need to configure a file to support this? It is working fine if I use multi-line comments (using /* Something */).

I googled and went through MySQL documentation. In that it has shown me it supports ( -- ). What could be the error?

回答1:

From MySQL documentation:

From a “-- ” sequence to the end of the line. In MySQL, the “-- ” (double-dash) comment style requires the second dash to be followed by at least one whitespace or control character (such as a space, tab, newline, and so on).

You need some space character after --, for example:

mysql> select 1;-- test select

回答2:

Your syntax is wrong - read about comment syntax.

Just add a space after --:

mysql> select 1; -- test select
+---+
| 1 |
+---+
| 1 |
+---+
1 row in set (0.00 sec)

来源：https://stackoverflow.com/questions/14435989/mysql-is-not-supporting-single-line-comments-here-what-would-be-the-reason